WO2019038789A1

WO2019038789A1 - A recombinant vector comprising a fusion dna for cell surface display, and uses thereof

Info

Publication number: WO2019038789A1
Application number: PCT/IN2018/050544
Authority: WO
Inventors: Preeti Srivastava; Sabita RANGRA
Original assignee: Indian Institute Of Technology, Delhi
Priority date: 2017-08-25
Filing date: 2018-08-24
Publication date: 2019-02-28

Abstract

The present disclosure provides a recombinant vector comprising BclB or BclA fused to a gene of interest encoding a fusion polypeptide for cell surface display of the fusion polypeptide. Also provided is a recombinant host cell comprising the recombinant vector and its uses, along with method of expressing the fusion polypeptide in the host cell.

Description

A RECOMBINANT VECTOR COMPRISING A FUSION DNA FOR CELL SURFACE DISPLAY, AND USES THEREOF

FIELD OF THE INVENTION

[1] The present disclosure relates to the field of recombinant DNA technology. In particular, the present disclosure relates to a recombinant vector comprising a fusion DNA for cell surface display of the fusion polypeptide encoded by the fusion DNA, and uses thereof. BACKGROUND OF THE INVENTION

[2] Cell membrane acts as a barrier between the cell constituents and its outer environment. Exchange of materials in cells takes place through two major pathways, namely, exocytic and endocytic pathway. As the name suggests, exocytic pathway aids in transporting materials synthesized in the cell to the outer environment, whereas, through endocytic pathway the cell internalizes the material from the outer environment into the cell (Tokarev et.al. Landes Bioscience and Springer Science+Business Media, 2009).

[3] Advances in the field of recombinant DNA technology have resulted in development of cell display systems such as phage and yeast display technology. The system allows display of intracellular peptides onto the host cell surface. The system can be exploited for various biotechnological and biomedical purposes, such as, screening of a target library, vaccine development, biosensors, and biocatalyst (Chen et.al. Biotechnol. Bioeng. 2002. 79(5): 496- 503).

[4] Amongst all the display system, phage display system is the most common type of display system employed for high throughput screening of peptide and enzyme libraries. However, there is a limitation with respect to the size of the heterologous protein that can be displayed using phage. [5] The display system mainly comprises a scaffold protein that is capable of displaying a heterologous peptide onto the host cell surface. Scaffold proteins such as OmpA of E. coli is used widely for surface display of peptides.

[6] US6919075 reveals a bacteriophage displaying aP epitopes for use in immunizing against plaque forming diseases.

[7] US 6300065 provides a genetic method for tethering polypeptides to the yeast cell wall in a form accessible for binding to macromolecules.

SUMMARY OF THE INVENTION

[8] In an aspect of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1.

[9] In an aspect of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1.

[10] In an aspect of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1.

[11] In an aspect of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein the fusion polypeptide having amino acid sequence is selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18.

[12] In an aspect of the present disclosure, there is provided a method for converting dibenzothiophene to dibenzothiophene sulfone, said method comprising: (a) obtaining a sample comprising dibenzothiophene; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 11, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene to dibenzothiophene sulfone, wherein said SEQ ID NO: 11 comprises a fusion of SEQ ID NO: 1 and SEQ ID no: 3.

[13] In an aspect of the present disclosure, there is provided a method for converting dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, said method comprising: (a) obtaining a sample comprising dibenzothiophene sulfone; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 15, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, wherein said SEQ ID NO: 15 is a fusion of SEQ ID NO: l and SEQ ID NO: 7. [14] In an aspect of the present disclosure, there is provided a method for converting hydroxyphenyl benzene sulfonate to hydroxybiphenyl, said method comprising: (a) obtaining a sample comprising hydroxyphenyl benzene sulfonate; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 17, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert hydroxyphenyl benzene sulfonate to hydroxybiphenyl, wherein said SEQ ID NO: 17 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 9.

[15] In an aspect of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19.

[16] In an aspect of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19.

[17] In an aspect of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19.

[18] In an aspect of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein the fusion polypeptide having amino acid sequence is selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO: 28.

[19] In an aspect of the present disclosure, there is provided a method for converting dibenzothiophene to dibenzothiophene sulfone, said method comprising: (a) obtaining a sample comprising dibenzothiophene; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 21, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene to dibenzothiophene sulfone, wherein said SEQ ID NO: 21 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 3.

[20] In an aspect of the present disclosure, there is provided a method for converting dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, said method comprising: (a) obtaining a sample comprising dibenzothiophene sulfone; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 25, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence is as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, wherein said SEQ ID NO: 25 comprises a sequence of SEQ ID NO: 19 and SEQ ID NO: 7.

[21] In an aspect of the present disclosure, there is provided a method for converting to hydroxyphenyl benzene sulfonate to hydroxybiphenyl, said method comprising: (a) obtaining a sample comprising hydroxyphenyl benzene sulfonate; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 27, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert hydroxyphenyl benzene sulfonate to hydroxybiphenyl, wherein said SEQ ID NO: 27 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 9.

[22] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[23] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.

[24] Figure 1A depicts the recombinant vector construct comprising DszC in pET 29a+ vector, in accordance with an embodiment of the present disclosure. [25] Figure IB depicts the recombinant vector construct comprising BclB+ DszC in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

[26] Figure 2A shows SDS gel image depicting the expression of intracellular and surface displayed DszC protein in induced and uninduced cell culture samples, in accordance with an embodiment of the present disclosure.

[27] Figure 2B shows SDS gel image depicting the expression of intracellular and surface displayed DszC protein in induced and uninduced cell culture supernatant and outer cell membrane fraction samples, in accordance with an embodiment of the present disclosure.

[28] Figure 3 represents a graph depicting the Peptide mass fingerprint data for DszC protein analysed by MALDI-ToF technique, in accordance with an embodiment of the present disclosure.

[29] Figure 4 represents a graph depicting the conversion of DBT to DBT sulfone by intracellular and surface displayed DszC enzyme, in accordance with an embodiment of the present disclosure.

[30] Figure 5 represents a graph depicting the effect of supplementing NADH as cofactor on production of DBT sulfone.

[31] Figure 6A represents thin layer chromatography data with cells containing surface displayed DszC enzyme, in accordance with an embodiment of the present disclosure.

[32] Figure 6B represents thin layer chromatography data with cells containing intracellular DszC enzyme, in accordance with an embodiment of the present disclosure.

[33] Figure 7 depicts the recombinant vector construct comprising BclB+ DszA (pSR3 +Ζ νζΑ) in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

[34] Figure 8 depicts the recombinant vector construct comprising BclB+ DszB (pSR3 +Ζ νζΑ) in pET 29a+ vector, in accordance with an embodiment of the present disclosure. [35] Figure 9 depicts the recombinant vector construct comprising BclB+ DszD (pSR3 +Ζ νζΑ) in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

[36] Figure 10 depicts the recombinant vector construct comprising BclA+ DszA (pSR4+ZXvzA) in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

[37] Figure 11 depicts the recombinant vector construct comprising BclA+ DszB (pSR4+ZXvzfi) in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

[38] Figure 12 depicts the recombinant vector construct comprising BclA+ DszD (pSR4+ZXvz ) in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

[39] Figure 13 depicts the recombinant vector construct comprising BclA+ DszC (pSR5) in pET 29a+ vector, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[40] Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions, and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features.

Definitions

[41] For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

[42] The articles "a", "an" and "the" are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

[43] The terms "comprise" and "comprising" are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as "consists of only".

[44] Throughout this specification, unless the context requires otherwise the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps.

[45] The term "including" is used to mean "including but not limited to". "Including" and "including but not limited to" are used interchangeably.

[46] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.

[47] Desulphurization is a chemical process of removal of sulphur from a material. The process is of particular importance as it allows removal of sulphur from fuels and petroleum hydrocarbon and thereby prevents the release of harmful sulphur compounds into the environment. Hydrodesulphurization is the conventional chemical process used in refineries for reduction of sulphur in fuels and petroleum. The process however, involves high cost and reduced energetic fuel value. An alternate to the above mentioned chemical process is bio-desulphurization which removes sulphur from fuels by means of living organisms. The added advantage of bio-desulphurization is that, it removes organosulphur from fuels without degrading the carbon skeleton of the compound. Desulphurization of dibenzothiophene requires mass transfer of substrate into the bacteria for making it accessible to the intracellular DszC enzyme, which is a limiting step.

[48] The present invention provides a recombinant vector which comprises a fusion DNA that encodes for a fusion polypeptide. The fusion DNA further comprises either BclA or BclB, and a gene of interest fused together to encode a fusion polypeptide. The recombinant vector when transformed in a host cell, drives the expression of the encoded fusion polypeptide onto the surface of the host cell, thereby forming a cell display system for the fusion polypeptide.

[49] One of the examples displayed in the present disclosure is that of the intracellular DszC enzyme, which is a monooxygenase useful for conversion of dibenzothiophene (DBT) to dibenzothiophene sulfone in 4S biodesulphurization pathway. A recombinant vector is produced comprising the gene encoding for DszC enzyme (SEQ ID NO: 3) fused with BclB (SEQ ID NO: 1) to form a fusion DNA (SEQ ID NO: 11) and transformed in a bacterial cell. Further the bacterial cell harbouring the recombinant vector when grown under suitable condition expresses the recombinant DszC polypeptide (SEQ ID NO: 12) on its surface, thereby making the polypeptide readily available for conversion of DBT to DBT sulfone. Similarly, a bacterial display system comprising BclA+ DszC has also been provided in the present disclosure. Thus, BclB and BclA are useful for the display of intracellular proteins on the surface of a host cell.

[50] Therefore, a person skilled in the art can use the present disclosed display system comprising BclA or BclB for displaying any protein encoded by a gene of interest onto the surface of range of host cells.

[51] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally-equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein.

[52] Table of sequences SEQ ID NO: 1 DNA - BclB - N-Terminal

SEQ ID NO: 2 Protein - BclB - N-Terminal

SEQ ID NO: 3 DNA - DszC

SEQ ID NO: 4 Protein - DszC

SEQ ID NO: 5 DNA - DszD

SEQ ID NO: 6 Protein - DszD

SEQ ID NO: 7 DNA - DszA

SEQ ID NO: 8 Protein - DszA

SEQ ID NO: 9 DNA - DszB

SEQ ID NO: 10 Protein - DszB

SEQ ID NO: 11 ΌΝΑ - BclB + DszC

SEQ ID NO: 12 Protein - BclB+ DszC

SEQ ID NO: 13 DNA - BclB+ DszD

SEQ ID NO: 14 Protein - BclB+ DszD

SEQ ID NO: 15 DNA - BclB+ DszA

SEQ ID NO: 16 Protein - BclB+ DszA

SEQ ID NO: 17 DNA - BclB+ DszB

SEQ ID NO: 18 Protein - BclB+ DszB

SEQ ID NO: 19 DNA - BclA - N-Terminal

SEQ ID NO: 20 Protein - BclA - N-Terminal

SEQ ID NO: 21 DNA - BclA + DszC

SEQ ID NO: 22 Protein - BclA+ DszC

SEQ ID NO: 23 DNA - BclA + DszD

SEQ ID NO: 24 Protein - BclA+ DszD

SEQ ID NO: 25 DNA - BclA + DszA SEQ ID NO: 26 Protein - BclA+ DszA

SEQ ID NO: 27 DNA - BclA + DszB

SEQ ID NO: 28 Protein - BclA+ DszB

SEQ ID NO: 29 Forward Primer for BclB

SEQ ID NO: 30 Reverse Primer for BclB

SEQ ID NO: 31 Forward Primer for DszC

SEQ ID NO: 32 Reverse Primer for DszC

SEQ ID NO: 33 Forward Primer for BclA

SEQ ID NO: 34 Reverse Primer for BclA

SEQ ID NO: 35 DNA - BclB full length

SEQ ID NO: 36 Protein - BclB full length

SEQ ID NO: 37 DNA - BclA full length

SEQ ID NO: 38 Protein - BclA full length

Sequences:

[53] SEQ ID NO: 1 depicts nucleotide sequence of N-terminal region of BclB

TTGAAACAGAATGACAAATTATGGTTGGATAAAGGCATAATAGGCCCAG AAAATATTGGACCTACCTTCCCGGTTCTTCCCCCA

[54] SEQ ID NO: 2 depicts amino acid sequence of N-terminal domain of BclB LKQNDKLWLDKGIIGPENIGPTFPVLPP

[55] SEQ ID NO: 3 depicts nucleotide sequence of DszC

ATGACTCTGTCCGTTGAAAAGCAGCACGTTCGACCCGGCGATGCCGACAA CGATCCCGTCGCAGTCGCCCGTGGGCTCGCCGAGAAGTGGCGAGCCACCG CCGTCGAGCGTGATCGCGCCGGGGGTTCGGCAACAGTCGAGCGCGAAGA CCTGCGCGCGAGCGGCCTGCTGTCGCTGCTGATCCCACGCCAGTACGGCG GGTGGGGCGCGGACTGGCCCACCGCCATCGAAGTGGTCCGAGAAATCGC CGCAGCCGATGGATCTTTGGGACACCTGCTCGGCTACCACCTCAGCAGCG CCCCGATGATCGAACTGTTCGGCTCGCAGGAACAAGAACAACGGCTATAC CGGCAAATCGCGCAGAACGACTGGTGGACCGGGAACGCCTCCAGCGAAA ACAACAGCCACGTGCTGGACTGGAAGGTCAGCGCCAGCCCGACCGAGGA CGGCGGTTATCTGCTCAACGGCACCAAGCACTTCTGCAGCGGCGCCAAGG GTTCGGACCTGTTGCTGGTCTTCGGCGTCATCCAGGACGATTCTCCGCAGC AGGGCGCGATCATCGCGGCCGTCATCCCGACATCCCGGCACGGCGTTCAG GTCAACGACGACTGGGCCGCCATCGGCATGCGGCAGACCGACAGCGGAT CCACCGATTTCCACAGCGTCAAGGTCGAGCCTGACGAAGTGCTGGGTGAG CCCAACGCCTTCATTGTCGCCTTCATCCAGTCCGAGCGCGGCAGCCTCTTC GCGCCCATAGTGCAATTGATCTTCGCCAACGTCTATTTAGGGATCGCGCA CGGCGCACTCGACGCCGCCCGGGAGTACACCCGCACTCAGGCCAGGCCAT GGACACCGGCCGGGGTTCAACAGGCAACCGAGGATCCCTACGTCCTGCGC GCCTATGGTGAATTCACCATCGCATTGCAGGGCGCCGACGCCGCTGCCCG CGAAGCGGCCCATCTGCTGCAGACGGTGTGGGACAAGGGCGATGCGCTC ACCCCCGAGGACCGCGGCGAACTGATGGTGAAGATCTCCGGGGTCAAAG CGTTGGCCACGAACGCCGCCCTCGACGTCAACAGCGGAATCTTCGAGGTG ATCGGAGCGCGCGGAACACATCCCAAGTACGGTTTCGACCGCTTCTGGCG CAACGTACGCACGCACACCCTCCACGATCCGGTGTCCTACAAGATCGCCG ACGTCGGCAAACACACCCTCAACGGGCAGTACCCGATTCCCGGCTTCACC TCCTAG

[56] SEQ ID NO: 4 depicts amino acid sequence of DszC protein

MTLSVEKQHVRPGDADNDPVAVARGLAEKWRATAVERDRAGGSATVERED LRASGLLSLLIPRQYGGWGADWPTAIEVVREIAAADGSLGHLLGYHLSSAPM IELFGSQEQEQRLYRQIAQNDWWTGNASSENNSHVLDWKVSASPTEDGGYL LNGTKHFCSGAKGSDLLLVFGVIQDDSPQQGAIIAAVIPTSRHGVQVNDDWA AIGMRQTDSGSTDFHSVKVEPDEVLGEPNAFIVAFIQSERGSLFAPIVQLIFAN VYLGIAHGALDAAREYTRTQARPWTPAGVQQATEDPYVLRAYGEFTIALQG ADAAAREAAHLLQTVWDKGDALTPEDRGELMVKISGVKALATNAALDVNS GIFEVIGARGTHPKYGFDRFWRNVRTHTLHDPVSYKIADVGKHTLNGQYPIP GFTS [57] SEQ ID NO: 5 depicts nucleotide sequence of DszD {Rhodococcus erythropolis accession number: AB051429.1)

ATGTCTGACAAGCCGAATGCCGTTTCCAGCCACACCACCCCCGACGTCCC CGAAGTAGCAGCGACGCCCGAGTTGTCCACCGGCATCTGCGCCGGTGACT ACCGTGCAGCGCTTCGCCGCCACCCCGCAGGTGTCACCGTCGTGACCCTC GATTCGGGTACCGGCCCGGTGGGTTTCACCGCCACCTCGTTCTCGTCCGTC TCCCTGGAGCCGCCGCTCGTCTCGTTCAACATCGCGGAGACGTCGTCGAG CATCAATGCGCTCAAGGCAGCCGAGTCCTTGGTGATCCACCTTCTCGGCG AACATCAGCAACATCTGGCCCAGCGCTTTGCGCGTAGCGCCGATCAGCGT TTTGCAGACGAGTCACTGTGGGCAGTGCTCGACACCGGGGAGCCGGTTCT GCACGGCACCCCCAGCTGGATGCGCGTCAAGGTCGACCAGTTGATCCCTG TCGGCGACCACACGCTGGTCATCGGACTCGTCACGCGGGTTCACGCCGAA GAGGACGACGAATCCGCTGCCGCACCGCTGCTCTACCACGAGGGCAAGT ACTACCGCCCGACTCCGTTA GGTCAATAG

[58] SEQ ID NO: 6 depicts amino acid sequence of DszD protein

MSDKPNAVSSHTTPDVPEVAATPELSTGICAGDYRAALRRHPAGVTVVTLDS GTGPVGFTATSFSSVSLEPPLVSFNIAETSSSINALKAAESLVIHLLGEHQQHLA QRFARSADQRFADESLWAVLDTGEPVLHGTPSWMRVKVDQLIPVGDHTLVI GLVTRVHAEEDDESAAAPLLYHEGKYYRPTPLGQ

[59] SEQ ID NO: 7 depicts nucleotide sequence of DszA

ATGGCTCAACGGCGACAACTGCATCTGGCCGGTTTCTTCTCGGCTGGCAA TGTGACTCATGCACATGGGGCGTGGCGGCATACGGACGCGTCGAATGGTT TTTTGACCGGGAAGTACTACCAACACATCGCCCGCACTCTGGAGCGCGGC AAGTTCGATCTGTTGTTCCTGCCTGACGGATTGGCCGTCGAGGACAGCTA CGGCGACGACCTGCGAACCGGTGTCGGCCTCGGCGGGCAGGGTGCAGTC GCCTTGGAGCCGGCCAGCGTGATAGCGACCATGGCCGCGGTCACCGAAC ACCTCGGTCTCGGGGCAACCATTTCGGCGACCTACTATCCCCCGTATCAC GTTGCTCGGGTGTTCGCGACGCTCGATCAATTGTCGGGGGGCCGGGTTTC GTGGAACGTGGTCACCTCGCTCAACGACGCTGAAGCGCGCAACTTCGGTA TTGATCAGCATCTGGAACACGACGCCCGTTACGACCGCGCCGATGAGTTC TTGGATGCGGTCAAGAAACTCTGGAACAGCTGGGATGAGGATGCGCTCGT ACTGGACAAGGCGGCAGGCGTGTTCGCCGATCCCACGAAGGTTCACTACG TGGATCACCACGGGGAGTGGCTGAATGTGCGCGGGCCTCTGCAGGTGCCT CGTTCACCTCAGGGTGAGCCGGTGATCCTGCAGGCCGGGTTGTCGCCGCG AGGTCGGCGCTTCGCCGGGCGGTGGGCCGAGGCCGTTTTCAGTGTCGCAC CCGATCTGGGATTGATGCAGGCTACATATCACGACATCAAAGCCCAGGTG AAGGCTGCGGGGCGTGATCCGGATCAGACGAAGATCTTCACCGCCGTGAT GCCGGTGTTGGGCGAGACCGAGGCCGTGGCGCAGGACCGGCTGGAATAC CTGAACAGTCTGGTGCATCCGGAGGTCGGACTTTCGACGCTGTCTAGTCA TACCGGCATCAACTTGGCGGAGTACCCGTTGGACACGCCGATCACGACGA TCCTGCGGGATCTGCAGGATCGCAACGTGCCGACGCAACTGCACATGTTC GCGGCCGCGATGCACGCCGAGGAGCTCACTTTGGCGGAGCTGGGTCGGC GGTATGGAACCAACGTGGGCTTCGTTCCGCAGTGGGCCGGCACGGCCGAG C AGATCGCCGAGGAGTTGATCCGCC ACTTCGACGCCGGCGCCGCGGATGG CTTCATTGTTTCTCCGGCCTTTCTGCCTGGCGCGTATGACGAATTCGTCGA CCAGGTGGTGCCGGTTCTGCAGGACCGCGGCTACTTCCGCACCGAATACG AGGGCAACACCCTGCGCGACCACCTGGGTCTGCGCGAACCACGACCGTTA GGACAACCTTCATGGCAGGCCGCCTCAGCCCCGGAAACCCCGGTTCAGAA CTTGATACCGGCATCCTCGACACACTGA

[60] SEQ ID NO: 8 depicts amino acid sequence of DszA protein

MAQRRQLHLAGFFSAGNVTHAHGAWRHTDASNGFLTGKYYQHIARTLERG KFDLLFLPDGLAVEDSYGDDLRTGVGLGGQGAVALEPASVIATMAAVTEHL GLGATISATYYPPYHVARVFATLDQLSGGRVSWNVVTSLNDAEARNFGIDQ HLEHDARYDRADEFLDAVKKLWNSWDEDALVLDKAAGVFADPTKVHYVD HHGEWLN VRGPLQ VPRS PQGEP VILQ AGLS PRGRRFAGRW AE A VFS V APDL GLMQATYHDIKAQVKAAGRDPDQTKIFTAVMPVLGETEAVAQDRLEYLNSL VHPEVGLSTLSSHTGINLAEYPLDTPITTILRDLQDRNVPTQLHMFAAAMHAE ELTLAELGRRYGTNVGFVPQWAGTAEQIAEELIRHFDAGAADGFIVSPAFLPG AYDEFVDQVVPVLQDRGYFRTEYEGNTLRDHLGLREPRPLGQPSWQAASAP ETPVQNLIPASSTH

[61] SEQ ID NO: 9 depicts nucleotide sequence of DszB

ATGGCAGGCCGCCTCAGCCCCGGAAACCCCGGTTCAGAACTTGATACCGG CATCCTCGACACACTGACCTACAGCAACTGCCCGATACCCAACGCGCTGC TCACGGCGTGGGAATCAGGTTTCCTCGACGCCGCCGGCATCGAACTCGAC ATCCTCAGCGGCAAGCAGGGAACGGTCCACTTCACCTACGACCAGCCCGC CTACACCCGCTATGGCGGTGAGATCCCGCCACTGCTCAGCGAGGGGTTGC GGGCACCCGGACGCACGCGTCTACTCGGCATCACCCCGATCCTGGGGCGT CAGGGCTTCTTCGTCGGCGATCGCAGCCCGATCACAGTGGCCGCCGACCT TGCCGGACGCCGAATAGGAGTGTCGGCTTCGGCGATTCGCATCCTGCGTG GCGAACTGGGGGACTATCTCCAGCTGGATCCCTGGCGGCAGACGCTGGTA GCGCTGGGCTCGTGGGAGGCGCGCGCGTTGTTGCACACCCTCGAGCACGG TGAGCTCGATGTGGACGACGTCGAGCTGGTGCCGATCAACAGTCCTGGCG TCGATGTCCCCGCCGAGCAGTTGG AAGACGCCGCG ACCCTCAAGGGTGCG GACCTGTTTCCCGATGTGGCCGCAGGCCAGGCCGCGGTGCTGGACCGCGG TGAGGTTGACGCCCTGTTCAGTTGGTTGCCCTGGGCTGCGGAGTTGGAAG GCACCGGCGCCCGCCCGGTGGTGGATCTCGGCCTCGATGAGCGCAATGCC TATGCCAGCGTGTGGACGGTCAGCAGCGAACTGGTCGTTGACCGGCCTGA CCTCGTTCAACGACTGGTCGACGCAGTCGTCGACGCCGGGTTGTGGGCAC GCGACCACGGCGATGCGGTGACCCGCCTGCACGCCGCGAACCTGGGCGT ATCCCCCGACGCAGTCGGCCACGGATTCGGCGCCGACTTCCAGCAGCGTT TGGTTCCGCGCCTGGATCCCGACGCGGTCGCCCTGCTGGATCGCACACAG CAATTCCTGCTCAGCAACCAGTTGCTGCAGGAGCCCGTCGCCCTCGATCA GTGGGCGGCTCCGGAATTTCTGAACACCAGCCTCAACCGTCACCGATAG

[62] SEQ ID NO: 10 depicts amino acid sequence of DszB protein

MAGRLSPGNPGSELDTGILDTLTYSNCPIPNALLTAWESGFLDAAGIELDILSG KQGTVHFTYDQPAYTRYGGEIPPLLSEGLRAPGRTRLLGITPILGRQGFFVGD RSPITVAADLAGRRIGVSASAIRILRGELGDYLQLDPWRQTLVALGSWEARAL LHTLEHGELDVDDVELVPINSPGVDVPAEQLEDAATLKGADLFPDVAAGQA AVLDRGEVDALFSWLPWAAELEGTGARPVVDLGLDERNAYASVWTVSSEL VVDRPDLVQRLVDAVVDAGLWARDHGDAVTRLHAANLGVSPDAVGHGFG ADFQQRLVPRLDPDAVALLDRTQQFLLSNQLLQEPVALDQWAAPEFLNTSLN RHR

[63] SEQ ID NO: 11 depicts nucleotide sequence of BclB+ DszC fusion DNA TTGAAACAGAATGACAAATTATGGTTGGATAAAGGCATAATAGGCCCAG AAAATATTGGACCTACCTTCCCGGTTCTTCCCCCAGAGCrCATGACTCTGT CCGTTGAAAAGCAGCACGTTCGACCCGGCGATGCCGACAACGATCCCGTC GCAGTCGCCCGTGGGCTCGCCGAGAAGTGGCGAGCCACCGCCGTCGAGC GTGATCGCGCCGGGGGTTCGGCAACAGTCGAGCGCGAAGACCTGCGCGC GAGCGGCCTGCTGTCGCTGCTGATCCCACGCCAGTACGGCGGGTGGGGCG CGGACTGGCCCACCGCCATCGAAGTGGTCCGAGAAATCGCCGCAGCCGAT GGATCTTTGGGACACCTGCTCGGCTACCACCTCAGCAGCGCCCCGATGAT CGAACTGTTCGGCTCGCAGGAAC AAGAAC AACGGCTATACCGGC AAATC GCGCAGAACGACTGGTGGACCGGGAACGCCTCCAGCGAAAACAACAGCC ACGTGCTGGACTGGAAGGTCAGCGCCAGCCCGACCGAGGACGGCGGTTA TCTGCTCAACGGCACCAAGCACTTCTGCAGCGGCGCCAAGGGTTCGGACC TGTTGCTGGTCTTCGGCGTCATCCAGGACGATTCTCCGCAGCAGGGCGCG ATCATCGCGGCCGTCATCCCGACATCCCGGCACGGCGTTCAGGTCAACGA CGACTGGGCCGCCATCGGCATGCGGCAGACCGACAGCGGATCCACCGATT TCCACAGCGTCAAGGTCGAGCCTGACGAAGTGCTGGGTGAGCCCAACGCC TTCATTGTCGCCTTCATCCAGTCCGAGCGCGGCAGCCTCTTCGCGCCCATA GTGCAATTGATCTTCGCCAACGTCTATTTAGGGATCGCGCACGGCGCACT CGACGCCGCCCGGGAGTACACCCGCACTCAGGCCAGGCCATGGACACCG GCCGGGGTTCAACAGGCAACCGAGGATCCCTACGTCCTGCGCGCCTATGG TGAATTCACCATCGCATTGCAGGGCGCCGACGCCGCTGCCCGCGAAGCGG CCCATCTGCTGCAGACGGTGTGGGACAAGGGCGATGCGCTCACCCCCGAG GACCGCGGCGAACTGATGGTGAAGATCTCCGGGGTCAAAGCGTTGGCCA CGAACGCCGCCCTCGACGTCAACAGCGGAATCTTCGAGGTGATCGGAGCG CGCGGAACACATCCCAAGTACGGTTTCGACCGCTTCTGGCGCAACGTACG CACGCACACCCTCCACGATCCGGTGTCCTACAAGATCGCCGACGTCGGCA AACACACCCTCAACGGGCAGTACCCGATTCCCGGCTTCACCTCCTAG

[64] SEQ ID NO: 12 depicts amino acid sequence of BclB+ DszC fusion polypeptide

LKQNDKLWLDKGIIGPENIGPTFPVLPPELMTLSVEKQHVRPGDADNDPVAV ARGLAEKWRATAVERDRAGGSATVEREDLRASGLLSLLIPRQYGGWGADW PTAIEVVREIAAADGSLGHLLGYHLSSAPMIELFGSQEQEQRLYRQIAQNDW WTGNASSENNSHVLDWKVSASPTEDGGYLLNGTKHFCSGAKGSDLLLVFGV IQDDSPQQGAIIAAVIPTSRHGVQVNDDWAAIGMRQTDSGSTDFHSVKVEPD EVLGEPNAFIVAFIQSERGSLFAPIVQLIFANVYLGIAHGALDAAREYTRTQAR PWTPAGVQQATEDPYVLRAYGEFTIALQGADAAAREAAHLLQTVWDKGDA LTPEDRGELMVKISGVKALATNAALDVNSGIFEVIGARGTHPKYGFDRFWRN VRTHTLHDPVS YKIAD VGKHTLNGQYPIPGFTS

[65] SEQ ID NO: 13 depicts nucleotide sequence of BclB+ DszD fusion DNA TTGAAACAGAATGACAAATTATGGTTGGATAAAGGCATAATAGGCCCAG AAAATATTGGACCTACCTTCCCGGTTCTTCCCCCAGAGCrCATGTCTGACA AGCCGAATGCCGTTTCCAGCCACACCACCCCCGACGTCCCCGAAGTAGCA GCGACGCCCGAGTTGTCCACCGGCATCTGCGCCGGTGACTACCGTGCAGC GCTTCGCCGCCACCCCGCAGGTGTCACCGTCGTGACCCTCGATTCGGGTA CCGGCCCGGTGGGTTTCACCGCCACCTCGTTCTCGTCCGTCTCCCTGGAGC CGCCGCTCGTCTCGTTCAACATCGCGGAGACGTCGTCGAGCATCAATGCG CTCAAGGCAGCCGAGTCCTTGGTGATCCACCTTCTCGGCGAACATCAGCA ACATCTGGCCCAGCGCTTTGCGCGTAGCGCCGATCAGCGTTTTGCAGACG AGTCACTGTGGGCAGTGCTCGACACCGGGGAGCCGGTTCTGCACGGCACC CCCAGCTGGATGCGCGTCAAGGTCGACCAGTTGATCCCTGTCGGCGACCA CACGCTGGTCATCGGACTCGTCACGCGGGTTCACGCCGAAGAGGACGACG AATCCGCTGCCGCACCGCTGCTCTACCACGAGGGCAAGTACTACCGCCCG ACTCCGTTAGGTCAATAG

[66] SEQ ID NO: 14 depicts amino acid sequence of BclB+ DszD fusion polypeptide

LKQNDKLWLDKGIIGPENIGPTFPVLPPELMSDKPNAVSSHTTPDVPEVAATP ELSTGICAGDYRAALRRHPAGVTVVTLDSGTGPVGFTATSFSSVSLEPPEVSF NIAETSSSINALKAAESLVIHLLGEHQQHLAQRFARSADQRFADESLWAVLDT GEPVLHGTPiSWMRVKVDQLIPVGDHTLVIGLVTRVHAEEDDESAAAPLLYH EGKYYRPTPLGQ

[67] SEQ ID NO: 15 depicts nucleotide sequence of BclB+ DszA fusion DNA

TTGAAACAGAATGACAAATTATGGTTGGATAAAGGCATAATAGGCCCAG AAAATATTGGACCTACCTTCCCGGTTCTTCCCCCAGAGCrCATGGCTCAAC GGCGACAACTGCATCTGGCCGGTTTCTTCTCGGCTGGCAATGTGACTCAT GCACATGGGGCGTGGCGGCATACGGACGCGTCGAATGGTTTTTTGACCGG G AAGTACTACCAAC AC ATCGCCCGCACTCTGGAGCGCGGC AAGTTCGATC TGTTGTTCCTGCCTGACGGATTGGCCGTCGAGGACAGCTACGGCGACGAC CTGCGAACCGGTGTCGGCCTCGGCGGGCAGGGTGCAGTCGCCTTGGAGCC GGCCAGCGTGATAGCGACCATGGCCGCGGTCACCGAACACCTCGGTCTCG GGGCAACCATTTCGGCGACCTACTATCCCCCGTATCACGTTGCTCGGGTGT TCGCGACGCTCGATCAATTGTCGGGGGGCCGGGTTTCGTGGAACGTGGTC ACCTCGCTCAACGACGCTGAAGCGCGCAACTTCGGTATTGATCAGCATCT GGAACACGACGCCCGTTACGACCGCGCCGATGAGTTCTTGGATGCGGTCA AGAAACTCTGGAACAGCTGGGATGAGGATGCGCTCGTACTGGACAAGGC GGCAGGCGTGTTCGCCGATCCCACGAAGGTTCACTACGTGGATCACCACG GGGAGTGGCTGAATGTGCGCGGGCCTCTGCAGGTGCCTCGTTCACCTCAG GGTGAGCCGGTGATCCTGCAGGCCGGGTTGTCGCCGCGAGGTCGGCGCTT CGCCGGGCGGTGGGCCGAGGCCGTTTTCAGTGTCGCACCCGATCTGGGAT TGATGCAGGCTACATATCACGACATCAAAGCCCAGGTGAAGGCTGCGGG GCGTGATCCGGATCAGACGAAGATCTTCACCGCCGTGATGCCGGTGTTGG GCGAGACCGAGGCCGTGGCGCAGGACCGGCTGGAATACCTGAACAGTCT GGTGCATCCGGAGGTCGGACTTTCGACGCTGTCTAGTCATACCGGCATCA ACTTGGCGGAGTACCCGTTGGACACGCCGATCACGACGATCCTGCGGGAT CTGCAGGATCGCAACGTGCCGACGCAACTGCACATGTTCGCGGCCGCGAT GCACGCCGAGGAGCTCACTTTGGCGGAGCTGGGTCGGCGGTATGGAACC AACGTGGGCTTCGTTCCGCAGTGGGCCGGCACGGCCGAGCAGATCGCCGA GGAGTTGATCCGCCACTTCGACGCCGGCGCCGCGGATGGCTTCATTGTTT CTCCGGCCTTTCTGCCTGGCGCGTATGACGAATTCGTCGACCAGGTGGTG CCGGTTCTGCAGGACCGCGGCTACTTCCGCACCGAATACGAGGGCAACAC CCTGCGCGACCACCTGGGTCTGCGCGAACCACGACCGTTAGGACAACCTT CATGGCAGGCCGCCTCAGCCCCGGAAACCCCGGTTCAGAACTTGATACCG GCATCCTCGACACACTGA

[68] SEQ ID NO: 16 depicts amino acid sequence of BclB+ DszA fusion polypeptide

LKQNDKLWLDKGIIGPENIGPTFPVLPPELMAQRRQLHLAGFFSAGNVTHAH GAWRHTDASNGFLTGKYYQHIARTLERGKFDLLFLPDGLAVEDSYGDDLRT GVGLGGQGAVALEPASViATMAAVTEHLGLGATISATYYPPYHVARVFATL DQLSGGRVSWNWTSLNDAEARNFGIDQHLEHDARYDRADEFLDAVKKLW NSWDEDALVLDKAAGVFADPTKVHYVDHHGEWL VRGPLQVPRSPQGEPV ILQAGLSPRGRRFAGRWAEAVFSVAPDLGLMQATYHDIKAQVKAAGRDPDQ TKIFTAVMPVIXiETEAVAQDRLEYLNSLVHPEVGLST SSHTGINLAEYPLDT PITTILRDLQDRNVPTQLHMFAAAMHAEELTLAELGRRYGTNVGFVPQWAG TAEQ1AEELIRHFDAGAADGFIVSPAFLPGAYDEFVDQVVPVLQDRGYFRTEY EGNTLRDHLGLREPRPLGQPSWQAASAPETPVQNLIPASSTH

[69] SEQ ID NO: 17 depicts nucleotide sequence of BclB+ DszB fusion DNA

TTGAAACAGAATGACAAATTATGGTTGGATAAAGGCATAATAGGCCCAG AAAATATTGGACCTACCTTCCCGGTTCTTCCCCCAGAGCrCATGGCAGGCC GCCTCAGCCCCGGAAACCCCGGTTCAGAACTTGATACCGGCATCCTCGAC ACACTGACCTACAGCAACTGCCCGATACCCAACGCGCTGCTCACGGCGTG GGAATCAGGTTTCCTCGACGCCGCCGGCATCGAACTCGACATCCTCAGCG GCAAGCAGGGAACGGTCCACTTCACCTACGACCAGCCCGCCTACACCCGC TATGGCGGTGAGATCCCGCCACTGCTCAGCGAGGGGTTGCGGGCACCCGG ACGCACGCGTCTACTCGGCATCACCCCGATCCTGGGGCGTCAGGGCTTCT TCGTCGGCGATCGCAGCCCGATCACAGTGGCCGCCGACCTTGCCGGACGC CGAATAGGAGTGTCGGCTTCGGCGATTCGCATCCTGCGTGGCGAACTGGG GGACTATCTCCAGCTGGATCCCTGGCGGCAGACGCTGGTAGCGCTGGGCT CGTGGGAGGCGCGCGCGTTGTTGCACACCCTCGAGCACGGTGAGCTCGAT GTGGACGACGTCGAGCTGGTGCCGATCAACAGTCCTGGCGTCGATGTCCC CGCCGAGCAGTTGGAAGACGCCGCGACCCTCAAGGGTGCGGACCTGTTTC CCGATGTGGCCGCAGGCCAGGCCGCGGTGCTGGACCGCGGTGAGGTTGA CGCCCTGTTCAGTTGGTTGCCCTGGGCTGCGGAGTTGGAAGGCACCGGCG CCCGCCCGGTGGTGGATCTCGGCCTCGATGAGCGCAATGCCTATGCCAGC GTGTGGACGGTCAGCAGCGAACTGGTCGTTGACCGGCCTGACCTCGTTCA ACGACTGGTCGACGC AGTCGTCGACGCCGGGTTGTGGGC ACGCGACCACG GCGATGCGGTGACCCGCCTGCACGCCGCGAACCTGGGCGTATCCCCCGAC GCAGTCGGCCACGGATTCGGCGCCGACTTCCAGCAGCGTTTGGTTCCGCG CCTGGATCCCGACGCGGTCGCCCTGCTGGATCGCACACAGCAATTCCTGC TCAGCAACCAGTTGCTGCAGGAGCCCGTCGCCCTCGATCAGTGGGCGGCT CCGGAATTTCTGAACACCAGCCTCAACCGTCACCGATAG

[70] SEQ ID NO: 18 depicts amino acid sequence of BclB+ DszB fusion polypeptide

LKQNDKLWLDKGIIGPENIGPTFPVLPPELMAGRLSPGNPGSELDTGILDTLTY SNCPIPNALLTAWESGFLDAAGIELDILSGKQGTVHFTYDQPAYTRYGGEIPPL LSEGLRAPGRTRLLGITPILGRQGFFVGDRSPITVAADLAGRRIGVSASAIRILPv GELGDYLQLDPWRQTLVALGSWEARALLHTLEHGELDVDDVELVPINSPGV DVPAEQLEDAATLKGADLFPDVAAGQAAVLDRGEVDALFSWLPWAAELEG TGARPVVDLGLDERNAYASVWTVSSELVVDRPDLVQRLVDAVVDAGLWAR DHGDAVTRLHAANLGVSPDAVGHGFGADFQQRLVPRLDPDAVALLDRTQQ FLLS NQLLQEP V ALDQW A APEFLNTS LNRHR

[71] SEQ ID NO: 19 depicts nucleotide sequence of N-terminal region of BclA ATGTCAAATAATAATTATTCAAATGGATTAAACCCCGATGAATCTTTATA GCTAGTGCATTTGACCCTAATCTTGTAGGACCTACATTACCACCGATACCA

[72] SEQ ID NO: 20 depicts amino acid sequence of N-terminal domain of BclA protein

MSNNNYSNGLNPDESLSASAFDPNLVGPTLPPIPPF

[73] SEQ ID NO: 21 depicts nucleotide sequence of BclA+ DszC fusion DNA ATGTCAAATAATAATTATTCAAATGGATTAAACCCCGATGAATCTTTATC AGCTAGTGCATTTGACCCTAATCTTGTAGGACCTACATTACCACCGATACC AGAGCrCATGACTCTGTCCGTTGAAAAGCAGCACGTTCGACCCGGCGATG CCGACAACGATCCCGTCGCAGTCGCCCGTGGGCTCGCCGAGAAGTGGCGA GCCACCGCCGTCGAGCGTGATCGCGCCGGGGGTTCGGCAACAGTCGAGC GCGAAGACCTGCGCGCGAGCGGCCTGCTGTCGCTGCTGATCCCACGCCAG TACGGCGGGTGGGGCGCGGACTGGCCCACCGCCATCGAAGTGGTCCGAG AAATCGCCGCAGCCGATGGATCTTTGGGACACCTGCTCGGCTACCACCTC AGCAGCGCCCCGATGATCGAACTGTTCGGCTCGCAGGAACAAGAACAAC GGCTATACCGGCAAATCGCGCAGAACGACTGGTGGACCGGGAACGCCTC CAGCGAAAACAACAGCCACGTGCTGGACTGGAAGGTCAGCGCCAGCCCG ACCGAGGACGGCGGTTATCTGCTCAACGGCACCAAGCACTTCTGCAGCGG CGCCAAGGGTTCGGACCTGTTGCTGGTCTTCGGCGTCATCCAGGACGATT CTCCGCAGCAGGGCGCGATCATCGCGGCCGTCATCCCGACATCCCGGCAC GGCGTTCAGGTCAACGACGACTGGGCCGCCATCGGCATGCGGCAGACCG ACAGCGGATCCACCGATTTCCACAGCGTCAAGGTCGAGCCTGACGAAGTG CTGGGTGAGCCCAACGCCTTCATTGTCGCCTTCATCCAGTCCGAGCGCGG CAGCCTCTTCGCGCCCATAGTGCAATTGATCTTCGCCAACGTCTATTTAGG GATCGCGCACGGCGCACTCGACGCCGCCCGGGAGTACACCCGCACTCAG GCCAGGCCATGGACACCGGCCGGGGTTCAACAGGCAACCGAGGATCCCT ACGTCCTGCGCGCCTATGGTGAATTCACCATCGCATTGCAGGGCGCCGAC GCCGCTGCCCGCGAAGCGGCCCATCTGCTGCAGACGGTGTGGGACAAGG GCGATGCGCTCACCCCCGAGGACCGCGGCGAACTGATGGTGAAGATCTCC GGGGTCAAAGCGTTGGCCACGAACGCCGCCCTCGACGTCAACAGCGGAA TCTTCGAGGTGATCGGAGCGCGCGGAACACATCCCAAGTACGGTTTCGAC CGCTTCTGGCGCAACGTACGCACGCACACCCTCCACGATCCGGTGTCCTA CAAGATCGCCGACGTCGGCAAACACACCCTCAACGGGCAGTACCCGATTC CCGGCTTCACCTCCTAG

[74] SEQ ID NO: 22 depicts amino acid sequence of BclA+ DszC fusion polypeptide

MSNNNYSNGLNPDESLSASAFDPNLVGPTLPPIPELMTLSVEKQHVRPGDAD

NDPVAVARGLAEKWRATAVERDRAGGSATVEREDLRASGLLSLLIPRQYGG

WGADWPTAIEVVREIAAADGSLGHLLGYHLSSAPMIELFGSQEQEQRLYRQI AQNDWWTGNASSENNSHVLDWKVSASPTEDGGYLLNGTKHFCSGAKGSDL LLVFGVIQDDSPQQGAIIAAVIPTSRHGVQVNDDWAAIGMRQTDSGSTDFHS VKVEPDEVLGEPNAFIVAFIQSERGSLFAPIVQLIFANVYLGIAHGALDAAREY TRTQARPWTPAGVQQATEDPYVLRAYGEFTIALQGADAAAREAAHLLQTV WDKGDALTPEDRGELMVKISGVKALATNAALDVNSGIFEVIGARGTHPKYG FDRFWRNVRTHTLHDPVSYKIADVGKHTLNGQYPIPGFTS

[75] SEQ ID NO: 23 depicts nucleotide sequence of BclA+ DszD fusion DNA ATGTCAAATAATAATTATTCAAATGGATTAAACCCCGATGAATCTTTATC AGCTAGTGCATTTGACCCTAATCTTGTAGGACCTACATTACCACCGATACC AGAGCrCATGTCTGACAAGCCGAATGCCGTTTCCAGCCACACCACCCCCG ACGTCCCCGAAGTAGCAGCGACGCCCGAGTTGTCCACCGGCATCTGCGCC GGTGACTACCGTGCAGCGCTTCGCCGCCACCCCGCAGGTGTCACCGTCGT GACCCTCGATTCGGGTACCGGCCCGGTGGGTTTCACCGCCACCTCGTTCTC GTCCGTCTCCCTGGAGCCGCCGCTCGTCTCGTTCAACATCGCGGAGACGT CGTCGAGCATCAATGCGCTCAAGGCAGCCGAGTCCTTGGTGATCCACCTT CTCGGCGAACATCAGCAACATCTGGCCCAGCGCTTTGCGCGTAGCGCCGA TCAGCGTTTTGCAGACGAGTCACTGTGGGCAGTGCTCGACACCGGGGAGC CGGTTCTGCACGGCACCCCCAGCTGGATGCGCGTCAAGGTCGACCAGTTG ATCCCTGTCGGCGACCACACGCTGGTCATCGGACTCGTCACGCGGGTTCA CGCCGAAGAGGACGACGAATCCGCTGCCGCACCGCTGCTCTACCACGAG GGCAAGTACTACCGCCCGACTCCGTTAGGTCAATAG

[76] SEQ ID NO: 24 depicts amino acid sequence of BclA+ DszD fusion polypeptide

MSNNNYSNGLNPDESLSASAFDPNLVGPTLPPIPELMSDKPNAVSSHTTPDVP EVAATPELSTGICAGDYRAALRRHPAGVTVVTLDSGTGPVGFTATSFSSVSLE PPLVSFNI AETS S S IN ALK A AES LVIHLLGEHQQHL AQRFARS ADQRFADES L WAVLDTGEPVLHGTPSWMRVKVDQLIPVGDHTLVIGLVTRVHAEEDDESAA APLLYHEGKYYRPTPLGQ

[77] SEQ ID NO: 25 depicts nucleotide sequence of BclA+ DszA fusion DNA ATGTCAAATAATAATTATTC AAATGG ATTAAACCCCG ATGAATCTTTATC AGCTAGTGCATTTGACCCTAATCTTGTAGGACCTACATTACCACCGATACC AGAGCrCATGGCTCAACGGCGACAACTGCATCTGGCCGGTTTCTTCTCGGC TGGCAATGTGACTCATGCACATGGGGCGTGGCGGCATACGGACGCGTCGA ATGGTTTTTTGACCGGGAAGTACTACCAACACATCGCCCGCACTCTGGAG CGCGGCAAGTTCGATCTGTTGTTCCTGCCTGACGGATTGGCCGTCGAGGA CAGCTACGGCGACGACCTGCGAACCGGTGTCGGCCTCGGCGGGCAGGGT GCAGTCGCCTTGGAGCCGGCCAGCGTGATAGCGACCATGGCCGCGGTCAC CGAACACCTCGGTCTCGGGGCAACCATTTCGGCGACCTACTATCCCCCGT ATCACGTTGCTCGGGTGTTCGCGACGCTCGATCAATTGTCGGGGGGCCGG GTTTCGTGGAACGTGGTCACCTCGCTCAACGACGCTGAAGCGCGCAACTT CGGTATTGATCAGCATCTGGAACACGACGCCCGTTACGACCGCGCCGATG AGTTCTTGGATGCGGTCAAGAAACTCTGGAACAGCTGGGATGAGGATGCG CTCGTACTGGACAAGGCGGCAGGCGTGTTCGCCGATCCCACGAAGGTTCA CTACGTGGATCACCACGGGGAGTGGCTGAATGTGCGCGGGCCTCTGCAGG TGCCTCGTTCACCTCAGGGTGAGCCGGTGATCCTGCAGGCCGGGTTGTCG CCGCGAGGTCGGCGCTTCGCCGGGCGGTGGGCCGAGGCCGTTTTCAGTGT CGCACCCGATCTGGGATTGATGCAGGCTACATATCACGACATCAAAGCCC AGGTGAAGGCTGCGGGGCGTGATCCGGATCAGACGAAGATCTTCACCGC CGTGATGCCGGTGTTGGGCGAGACCGAGGCCGTGGCGCAGGACCGGCTG GAATACCTGAACAGTCTGGTGCATCCGGAGGTCGGACTTTCGACGCTGTC TAGTCATACCGGCATCAACTTGGCGGAGTACCCGTTGGACACGCCGATCA CGACGATCCTGCGGGATCTGCAGGATCGCAACGTGCCGACGCAACTGCAC ATGTTCGCGGCCGCGATGCACGCCGAGGAGCTCACTTTGGCGGAGCTGGG TCGGCGGTATGGAACCAACGTGGGCTTCGTTCCGCAGTGGGCCGGCACGG CCGAGCAGATCGCCGAGGAGTTGATCCGCCACTTCGACGCCGGCGCCGCG GATGGCTTCATTGTTTCTCCGGCCTTTCTGCCTGGCGCGTATGACGAATTC GTCGACCAGGTGGTGCCGGTTCTGCAGGACCGCGGCTACTTCCGCACCGA ATACGAGGGCAACACCCTGCGCGACCACCTGGGTCTGCGCGAACCACGA CCGTTAGGACAACCTTCATGGCAGGCCGCCTC AGCCCCGGAAACCCCGGT TCAGAACTTGATACCGGCATCCTCGACACACTGA

[78] SEQ ID NO: 26 depicts amino acid sequence of BclA+ DszA fusion polypeptide

MSNNNYSNGLNPDESLSASAFDPNLVGPTLPPIPELMAQRRQLHLAGFFSAG NVTHAHGAWRHTDASNGFLTGKYYQHIARTLERGKFDLLFLPDGLAVEDSY GDDLRTGVGLGGQGAVALEPASVIATMAAVTEHLGLGATISATYYPPYHVA RVFATLDQLSGGRVSWNVVTSLNDAEARNFGIDQHLEHDARYDRADEFLDA VKKLWNSWDEDALVLDKAAGVFADPTKVHYVDHHGEWLNVRGPLQVPRS PQGEPVILQAGLSPRGRRFAGRWAEAVFSVAPDLGLMQATYHDIKAQVKAA GRDPDQTKIFTAVMPVLGETEAVAQDRLEYLNSLVHPEVGLSTLSSHTGINLA EYPLDTPITTILRDLQDRNVPTQLHMFAAAMHAEELTLAELGRRYGTNVGFV PQWAGTAEQIAEELIRHFDAGAADGFIVSPAFLPGAYDEFVDQVVPVLQDRG YFRTEYEGNTLRDHLGLREPRPLGQPSWQAASAPETPVQNLIPASSTH

[79] SEQ ID NO: 27 depicts nucleotide sequence of BclA+ DszB fusion DNA ATGTCAAATAATAATTATTCAAATGGATTAAACCCCGATGAATCTTTATC AGCTAGTGCATTTGACCCTAATCTTGTAGGACCTACATTACCACCGATACC AGAGCrCATGGCAGGCCGCCTCAGCCCCGGAAACCCCGGTTCAGAACTTG ATACCGGCATCCTCGACACACTGACCTACAGCAACTGCCCGATACCCAAC GCGCTGCTCACGGCGTGGGAATCAGGTTTCCTCGACGCCGCCGGCATCGA ACTCGACATCCTCAGCGGCAAGCAGGGAACGGTCCACTTCACCTACGACC AGCCCGCCTACACCCGCTATGGCGGTGAGATCCCGCCACTGCTCAGCGAG GGGTTGCGGGCACCCGGACGCACGCGTCTACTCGGCATCACCCCGATCCT GGGGCGTCAGGGCTTCTTCGTCGGCGATCGCAGCCCGATCACAGTGGCCG CCGACCTTGCCGGACGCCGAATAGGAGTGTCGGCTTCGGCGATTCGCATC CTGCGTGGCGAACTGGGGGACTATCTCCAGCTGGATCCCTGGCGGCAGAC GCTGGTAGCGCTGGGCTCGTGGGAGGCGCGCGCGTTGTTGCACACCCTCG AGCACGGTGAGCTCGATGTGGACGACGTCGAGCTGGTGCCGATCAACAGT CCTGGCGTCGATGTCCCCGCCGAGCAGTTGGAAGACGCCGCGACCCTCAA GGGTGCGGACCTGTTTCCCGATGTGGCCGCAGGCCAGGCCGCGGTGCTGG ACCGCGGTGAGGTTGACGCCCTGTTCAGTTGGTTGCCCTGGGCTGCGGAG TTGGAAGGCACCGGCGCCCGCCCGGTGGTGGATCTCGGCCTCGATGAGCG CAATGCCTATGCCAGCGTGTGGACGGTCAGCAGCGAACTGGTCGTTGACC GGCCTGACCTCGTTCAACGACTGGTCGACGCAGTCGTCGACGCCGGGTTG TGGGCACGCGACCACGGCGATGCGGTGACCCGCCTGCACGCCGCGAACCT GGGCGTATCCCCCGACGCAGTCGGCCACGGATTCGGCGCCGACTTCCAGC AGCGTTTGGTTCCGCGCCTGGATCCCGACGCGGTCGCCCTGCTGGATCGC ACACAGCAATTCCTGCTCAGCAACCAGTTGCTGCAGGAGCCCGTCGCCCT CGATCAGTGGGCGGCTCCGGAATTTCTGAACACCAGCCTCAACCGTCACC GATAG

[80] SEQ ID NO: 28 depicts amino acid sequence of BclA+ DszB fusion polypeptide

MSNNNYSNGLNPDESLSASAFDPNLVGPTLPPIPELMAGRLSPGNPGSELDTG ILDTLTYSNCPIPNALLTAWESGFLDAAGIELDILSGKQGTVHFTYDQPAYTR YGGEIPPLLSEGLRAPGRTRLLGITPILGRQGFFVGDRSPITVAADLAGRRIGVS ASAIRILRGELGDYLQLDPWRQTLVALGSWEARALLHTLEHGELDVDDVEL VPINSPGVDVPAEQLEDAATLKGADLFPDVAAGQAAVLDRGEVDALFSWLP WAAELEGTGARPVVDLGLDERNAYASVWTVSSELVVDRPDLVQRLVDAVV DAGLWARDHGDAVTRLHAANLGVSPDAVGHGFGADFQQRLVPRLDPDAVA LLDRTQQFLLSNQLLQEPVALDQWAAPEFLNTSLNRHR

[81] SEQ ID NO: 29 depicts forward primer sequence for BclB

GCT ACA 7A 7GTTGA AAC AG A ATG AC A A ATT ATG

[82] SEQ ID NO: 30 depicts reverse primer sequence for BclB

GTCAGAGC7XTGGGGGAAGAACCGGGAAGGTAGG

[83] SEQ ID NO: 31 depicts forward primer sequence for DszC

GTCAGAGC7XATGACTCTGTCCGTTGAAAAGCAGCAC

[84] SEQ ID NO: 32 depicts reverse primer sequence for DszC

CCGCCCAAGC7TCTAGGAGGTGAAGCCGGGAATCGGGTA

[85] SEQ ID NO: 33 depicts forward primer sequence for BclA

GCTACA TA 7GGCTAC ATATGTCAAATA ATA ATTATTC

[86] SEQ ID NO: 34 depicts reverse primer sequence for BclA

GTCAGAGC7XTGACGAGCTCTGGTATCGGTGGTAATG

[87] SEQ ID NO: 35 depicts nucleotide sequence of full length BclB

TTGAAACAGAATGACAAATTATGGTTGGATAAAGGCATAATAGGCCCAG AAAATATTGGACCTACCTTCCCGGTTCTTCCCCCAATTCATATTCCAACAG GAATAACGGGAGCAACCGGTGCAACAGGAATAACGGGAGCAACAGGTCC GACGGGAACAACAGGAGCGACCGGTGCGACAGGAATAACGGGAGTGACC GGTGCAACAGGAATAACGGGAGTGACCGGTGCAACAGGAATAACGGGAG TGACCGGTGCAACAGGAATAACGGGAGTGACCGGTGCAACAGGAATAAC GGGAGTGACAGGTCCGACGGGAATAACGGGAGCAACAGGTCCGACGGGA ACAACAGGAGTAACCGGTCCAACGGGAGACACAGGTCTAGCAGGAGCAA CGGGCCCGACAGGAGCAACAGGTCTAGCAGGAGCAACGGGCCCAACAGG AGATACTGGAGCAACGGGCCCGACAGGAGCAACAGGTCTAGCAGGAGCA ACAGGCCCGACAGGAGCAACAGGTCTAACGGGAGCAACTGGTGCAACAG GAGCAACTGGTGGCGGAGCTATTATTCCATTCGCTTCCGGTACAACACCA GCTCTGTTAGTTAATGCGGTATTAGCTAATACAGGGACTCTTCTTGGATTT GGATTTAGTCAGCCTGGCATAGCTCCAGGTGTGGGAGGAACTCTCACAAT ACTACCAGGTGTTGTAGGTGATTATGCATTTGTAGCACCACGTGATGGAA TTATCACTTCATTAGCAGGATTCTTTAGTGCAACAGCGGCGTTAGCTCCAT TGACACCTGTTCAAATTCAGATGCAAATATTTATCGCACCTGCTGCAAGT AATACGTTTACACCAGTAGCGCCACCTCTATTATTAACACCAGCATTACC AGCAATAGCAATTGGTACTACAGCAACAGGAATCCAAGCTTATAATGTTC CAGTAGTTGCTGGGGATAAAATATTAGTATATGTTTCATTAACAGGAGCT AGTCCAATAGCTGCAGTTGCCGGATTTGTAAGCGCAGGTCTTAATATC GTCTAA

[88] SEQ ID NO: 36 depicts amino acid sequence of BclB protein

LKQNDKLWLDKGIIGPENIGPTFPVLPPIHIPTGITGATGATGITGATGPTGTTG ATGATGITGVTGATGITGVTGATGITGVTGATGITGVTGATGITGVTGPTG1T GATGPTGTTGVTGPTGDTGLAGATGPTGATGLAGATGPTGDTGATGPTGAT GLAGATGPTGATGLTGATGATGATGGGAIIPFASGTTPALLVNAVLANTGTL LGFGFSQPGIAPGVGGTLTiLPGVVGDYAFVAPRDGirrSLAGFFSATAALAPL TPVQIQMQIFIAPAASNTFTPVAPPLLLTPALPAIAIGTTATGIQAYNVPVVAG DKJLVYVSLTGASPIAAVAGFVSAGLNIV

[89] SEQ ID NO: 37 depicts nucleotide sequence of full length BclA

ATGTCAAATAATAATTATTCAAATGGATTAAACCCCGATGAATCTTTATC AGCTAGTGCATTTGACCCTAATCTTGTAGGACCTACATTACCACCGATACC ACCATTTACCCTTCCTACCGGACCAACTGGGCCGACTGGACCGACTGGGC CGACTGGGCCAACTGGACCAACTGGGCCGACTGGGCCAACTGGACCAAC TGGACCAACTGGGCCAACTGGACCAACTGGGCCAACTGGGCCAACTGGA GACACTGGTACTACTGGACCAACTGGGCCAACTGGACCAACTGGACCAAC TGGGCCAACTGGTGCTACCGGACTGACTGGACCGACTGGACCGACTGGGC CATCCGGACTAGGACTTCCAGCAGGACTATATGCATTTAACTCCGGTGGG ATTTCTTTAGATTTAGGAATTAATGATCCAGTACCATTTAATACTGTTGGA TCTCAGTTTGGTACAGCAATTTCTCAATTAGATGCTGATACTTTCGTAATT AGTGAAACTGGATTCTATAAAATTACTGTTATCGCTAATACTGCAACAGC AAGTGTATTAGGAGGTCTTACAATCCAAGTGAATGGAGTACCTGTACCAG GTACTGGATCAAGTTTGATTTCACTCGGAGCACCTATCGTTATTCAAGCAA TTACGCAAATTACGACAACTCCATCATTAGTTGAAGTAATTGTTACAGGG CTTGGACTATCACTAGCTCTTGGCACGAGTGCATCCATTATTATTGAAAAA GTTGCTTAA

[90] SEQ ID NO: 38 depicts amino acid sequence of BclA protein

MSNNNYSNGLNPDESLSASAFDPNLVGPTLPPIPPFTLPTGPTGPTGPTGPTGP TGPTGPTGPTGPTGPTGPTGPTGPTGPTGDTGTTGPTGPTGPTGPTGPTGATGL TGPTGPTGPS GLGLP AGLY AFNS GGIS LDLGINDP VPFNT VGS QFGT AIS QLD A DTFVISETGFYKITVIANTATASVLGGLTIQVNGVPVPGTGSSLISLGAPIVIQAI TQITTTPSLVEVIVTGLGLSLALGTSASIIIEKVA

[91] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: l.

[92] In an embodiment of the present disclosure, there is provided a recombinant vector as described herein, wherein the promoter is selected from the group consisting of T7 promoter, Tac promoter, and Trc promoter.

[93] In an embodiment of the present disclosure, there is provided a recombinant vector as described herein, wherein the promoter is T7 promoter.

[94] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 14. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 18.

[95] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 12, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1. In another embodiment, the gene of interest is represented by SEQ ID NO: 3

[96] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO:3, SEQ ID NO:5, SEQ ID NO:7, and SEQ ID NO:9, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9

[97] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 11, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3, and said SEQ ID NO: 11 is a fusion of SEQ ID NO: 1 and SEQ ID NO: 3. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. [98] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 13, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5, and said SEQ ID NO: 13 is a fusion of SEQ ID NO: 1 and SEQ ID NO: 5. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 14.

[99] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 15, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7, and said SEQ ID NO: 15 is a fusion of SEQ ID NO: 1 and SEQ ID NO: 7. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 16.

[100] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 17, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9, and said SEQ ID NO: 17 is a fusion of SEQ ID NO: 1 and SEQ ID NO: 9. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 18

[101] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest.

[102] In an embodiment of the present disclosure, there is provided a recombinant host cell as described herein, wherein the host cell is selected from the group consisting of a bacteriophage, a bacterial cell, an yeast cell, a plant cell, and a fungal cell. [103] In an embodiment of the present disclosure, there is provided a recombinant host cell as described herein, wherein the host cell is a bacterial cell.

[104] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 14. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 18.

[105] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 12, wherein the fusion DNA comprises BclB having nucleotide sequence is as set forth in SEQ ID NO: 1, and a gene of interest. In an embodiment, the fusion DNA is represented by SEQ ID NO: 11, and the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[106] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence is as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9.

[107] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 11, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3, wherein SEQ ID NO: 11 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[108] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 13, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5, wherein SEQ ID NO: 13 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 5. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 14. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[109] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 15, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7, wherein SEQ ID NO: 15 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter. [110] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 17, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9, wherein SEQ ID NO: 17 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 9. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 18. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[111] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1. In another embodiment, the promoter is T7 promoter.

[112] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 14. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 18.

[113] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 12, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest. In an embodiment, the fusion DNA is represented by SEQ ID NO: 11, and the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the promoter is T7 promoter.

[114] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence is as set forth in SEQ ID NO: 1 , and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. IN one of the embodiment, the gene of interest is represented by SEQ ID NO: 9.

[115] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 11, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3, and said SEQ ID NO: 11 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the promoter is T7 promoter. In yet another embodiment, the bacterial cell display system is used for conversion of dibenzothiophene to dibenzothiophene sulfone.

[116] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 13, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5, and said SEQ ID NO: 13 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 5. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 14.

[117] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 15, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7, and said SEQ ID NO: 15 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 7. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In yet another embodiment, the bacterial cell display system is used for conversion of dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate.

[118] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 17, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9, and said SEQ ID NO: 17 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 9. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 18. In yet another embodiment, the bacterial display system is used for conversion of hydroxyphenyl benzene sulfonate to hydroxybiphenyl .

[119] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1 ; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18.1n an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 14. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 18.

[120] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface as described herein, wherein the host cell is selected from the group comprising of a bacteriophage, a bacterial cell, an yeast cell, a plant cell, and a fungal cell.

[121] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface as described herein, wherein the host cell is a bacterial cell.

[122] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest; (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 12. In one of the embodiment, the fusion DNA is represented by SEQ ID NO: 11, and the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the host cell is a bacterial cell.

[123] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence is as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9. In one of the other embodiment, the host cell is a bacterial cell.

[124] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 11, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein said SEQ ID NO: 11 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the host cell is a bacterial cell. In yet another embodiment the promoter is T7 promoter.

[125] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 13, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein said SEQ ID NO: 13 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 5. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 14. In another embodiment, the host cell is a bacterial cell.

[126] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 15, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein said SEQ ID NO: 15 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In another embodiment, the host cell is a bacterial cell.

[127] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 17, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein said SEQ ID NO: 17 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 9. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 18. In another embodiment, the host cell is a bacterial cell.

[128] In an embodiment of the present disclosure, there is provided a method for converting dibenzothiophene to dibenzothiophene sulfone, said method comprising: (a) obtaining a sample comprising dibenzothiophene; (b) obtaining a recombinant host cell comprising the recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 11, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene to dibenzothiophene sulfone, wherein said SEQ ID NO: 11 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 12. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[129] In an embodiment of the present disclosure, there is provided a method for converting dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, said method comprising: (a) obtaining a sample comprising dibenzothiophene sulfone; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 15, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, wherein said SEQ ID NO: 15 is a fusion of SEQ ID NO: l and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 16. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[130] In an embodiment of the present disclosure, there is provided a method for converting hydroxyphenyl benzene sulfonate to hydroxybiphenyl, said method comprising: (a) obtaining a sample comprising hydroxyphenyl benzene sulfonate; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 17, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB having nucleotide sequence as set forth in SEQ ID NO: 1, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert hydroxyphenyl benzene sulfonate to hydroxybiphenyl, wherein said SEQ ID NO: 17 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 9. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 18. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[131] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19.

[132] In an embodiment of the present disclosure, there is provided a recombinant vector as described herein, wherein the promoter is selected from the group consisting of T7 promoter, Tac promoter, and Trc promoter.

[133] In an embodiment of the present disclosure, there is provided a recombinant vector as described herein, wherein the promoter is T7 promoter.

[134] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO: 28, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 28.

[135] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 22, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19. In another embodiment, the gene of interest is represented by SEQ ID NO: 3. In yet another embodiment, the promoter is T7 promoter.

[136] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9

[137] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 21, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3, and SEQ ID NO: 11 is a fusion of SEQ ID NO: 19 and SEQ ID NO: 3. In another embodiment the fusion polypeptide is represented by SEQ ID NO: 22.

[138] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 23, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5, and SEQ ID NO: 23 is a fusion of SEQ ID NO: 19 and SEQ ID NO: 5. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 24.

[139] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 25, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7, and SEQ ID NO: 25 is a fusion of SEQ ID NO: 19 and SEQ ID NO: 7. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 26.

[140] In an embodiment of the present disclosure, there is provided a recombinant vector comprising a fusion DNA represented by SEQ ID NO: 27, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9, and SEQ ID NO: 27 is a fusion of SEQ ID NO: 19 and SEQ ID NO: 9. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 28

[141] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest.

[142] In an embodiment of the present disclosure, there is provided a recombinant host cell as described herein, wherein the host cell is selected from the group consisting of a bacteriophage, a bacterial cell, an yeast cell, a plant cell, and a fungal cell.

[143] In an embodiment of the present disclosure, there is provided a recombinant host cell as described herein, wherein the host cell is a bacterial cell. [144] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO: 28, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 28.

[145] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 22, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest. In an embodiment, the fusion DNA is represented by SEQ ID NO: 21, and the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[146] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9. [147] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 21, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3, wherein SEQ ID NO: 21 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[148] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 23, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5, wherein SEQ ID NO: 23 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 5. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In another embodiment the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[149] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 25, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7, wherein SEQ ID NO: 25 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In another embodiment the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[150] In an embodiment of the present disclosure, there is provided a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 27, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9, wherein SEQ ID NO: 27 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 9. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 28. In another embodiment the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[151] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19. In another embodiment, the promoter is T7 promoter.

[152] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO: 28, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 28.

[153] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 22, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest. In an embodiment, the fusion DNA is represented by SEQ ID NO: 21, and the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the promoter is T7 promoter. In yet another embodiment, the bacterial display system is used for conversion of dibenzothiophene to dibenzothiophene sulfone.

[154] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence is as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9.

[155] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 21, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3, and SEQ ID NO: 21 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 3. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In yet another embodiment, the promoter is T7 promoter.

[156] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 23, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5, and SEQ ID NO: 23 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 5. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In yet another embodiment, the promoter is T7 promoter.

[157] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 25, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7, and SEQ ID NO: 25 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. . In another embodiment, the promoter is T7 promoter. In yet another embodiment, the bacterial display system can is used for conversion of dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate.

[158] In an embodiment of the present disclosure, there is provided a bacterial cell display system comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 27, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9, and said SEQ ID NO: 27 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 9. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 28. In yet another embodiment, the bacterial display system is used for conversion of hydroxyphenyl benzene sulfonate to hydroxybiphenyl .

[159] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence as set forth in SEQ ID NO: 19; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide having amino acid sequence selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO: 28. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In yet another embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In one of the embodiment, the fusion polypeptide is represented by SEQ ID NO: 28.

[160] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface as described herein, wherein the host cell is selected from the group comprising of a bacteriophage, a bacterial cell, an yeast cell, a plant cell, and a fungal cell.

[161] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface as described herein, wherein the host cell is a bacterial cell.

[162] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest; (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 22. In one of the embodiment, the fusion DNA is represented by SEQ ID NO: 21, and the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the host cell is a bacterial cell. In another embodiment, the promoter is T7 promoter.

[163] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence is as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide. In an embodiment, the gene of interest is represented by SEQ ID NO: 3. In another embodiment, the gene of interest is represented by SEQ ID NO: 5. In yet another embodiment, the gene of interest is represented by SEQ ID NO: 7. In one of the embodiment, the gene of interest is represented by SEQ ID NO: 9. In one of the other embodiment, the host cell is a bacterial cell.

[164] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 21, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein SEQ ID NO: 21 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[165] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 23, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 5; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein SEQ ID NO: 23 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 5. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 24. In another embodiment, the host cell is a bacterial cell.

[166] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 25, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein SEQ ID NO: 25 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In another embodiment, the host cell is a bacterial cell.

[167] In an embodiment of the present disclosure, there is provided a method for expressing a fusion polypeptide on a host cell surface, said method comprising: (a) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 27, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9; and (b) growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein SEQ ID NO: 27 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 9. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 28. In another embodiment, the host cell is a bacterial cell.

[168] In an embodiment of the present disclosure, there is provided a method for converting dibenzothiophene to dibenzothiophene sulfone, said method comprising: (a) obtaining a sample comprising dibenzothiophene; (b) obtaining a recombinant host cell comprising the recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 21, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 3; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene to dibenzothiophene sulfone, wherein said SEQ ID NO: 21 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 3. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 22. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[169] In an embodiment of the present disclosure, there is provided a method for converting dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, said method comprising: (a) obtaining a sample comprising dibenzothiophene sulfone; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 25, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 7; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, wherein SEQ ID NO: 25 is a fusion of SEQ ID NO: 19 and SEQ ID NO: 7. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 26. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[170] In an embodiment of the present disclosure, there is provided a method for converting hydroxyphenyl benzene sulfonate to hydroxybiphenyl, said method comprising: (a) obtaining a sample comprising hydroxyphenyl benzene sulfonate; (b) obtaining a recombinant host cell comprising a recombinant vector, said vector comprising a fusion DNA represented by SEQ ID NO: 27, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA having nucleotide sequence as set forth in SEQ ID NO: 19, and a gene of interest having nucleotide sequence as set forth in SEQ ID NO: 9; (c) contacting the sample with the host cell of step (b) to obtain a mixture; and (d) incubating the mixture under suitable conditions for the growth of the host cell to convert hydroxyphenyl benzene sulfonate to hydroxybiphenyl, wherein SEQ ID NO: 27 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 9. In an embodiment, the fusion polypeptide is represented by SEQ ID NO: 28. In another embodiment, the host cell is a bacterial cell. In yet another embodiment, the promoter is T7 promoter.

[171] In an embodiment of the present disclosure, there is provided a bacterial cell surface display system as described herein, wherein the bacterial cell surface display system is used for bio-desulfurization of Dibenzothiophene (DBT).

[172] Although the subject matter has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the subject matter, will become apparent to persons skilled in the art upon reference to the description of the subject matter. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present subject matter as defined.

EXAMPLES

[173] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may vary.

The examples provided below illustrate the display system comprising BclB+ DszC and BclA+DszC. It also provides the recombinant vector constructs of BclB+ DszA, BclB+ DszB, BclB+ DszD, BclA+ DszA, BclA+ DszB, BclA+ DszD. The illustration can further be followed for producing display system comprising either BclB or BclA fused with a gene of interest encoding a fusion polypeptide for the purpose of displaying the fusion polypeptide onto the surface of a host cell.

Example 1

Materials and Methods

[174] Construction of the plasmid for bacterial cell surface display in E. coli: The present example illustrates the preparation of recombinant vectors and includes the recombinant vector BclB+DszC and BclA+DszC. Sequences for other recombinant DNA, viz. BclB+DszA, BclB+DszB, BclB+DszD, BclA+DszA, BclA+DszB, BclA+DszD has also been provided in the current specification and a person skilled in the art will be able to prepare the recombinant vector constructs comprising the aforementioned genes. The recombinant vector constructs for all the recombinant DNA has also been provided as below:

[175] Following plasmid constructs were prepared for the present study:

1. Plasmid comprising only BclB gene (pSR3, MTCC 25147): N-terminal region of BclB gene (sequence as shown in SEQ ID NO: 1) was amplified from the genomic DNA of Bacillus anthracis sterne using BclB-F and BclB-R primers (sequence as shown in SEQ ID NO: 29 and SEQ ID NO: 30), and cloned between Ndel and Sad restriction sites in pET29a+ plasmid containing T7 promoter. The plasmid obtained was named as pSR3. The PCR program employed for amplification of BclB gene was: 95 °C- 3 min (initial denaturation), 95 °C- 1 min, 58 °C- 1 min, 72 °C- 1 min (30 cycles), 72 °C- 10 min (final extension).

2. Plasmid comprising only DszC gene (pSRl, MTCC 25145): DszC gene (sequence as shown in SEQ ID NO: 3) was amplified from the genomic DNA of Gordonia species (IITR100 MCC2877) using DszC-F and DszC-R primers (Sequences as shown in SEQ ID NO: 31 and SEQ ID NO: 32). Polymerase chain reaction (PCR) was performed using PCR thermal cycler (Eppendorf, Master cycler, Nexus gradient, Germany). The PCR program employed for amplification of DszC gene was: 95 °C- 3 min (initial denaturation), 95 °C- 1 min, 58 °C- 1 min, 72 °C- 2 min (30 cycles), 72 °C - 10 min (final extension). The PCR product obtained was digested with Hindlll and Sacl restriction enzymes and ligated to pET29a+ digested with the same restriction enzymes. The construct obtained was transformed in DH5-a host cell and named as pSRl (depicted in Figure 1).

3. Bacterial cell display system comprising BclB and DszC (pSR 2, MTCC 25146): In order to clone BclB gene to DszC gene, pSRl was used as vector. It was digested with restriction enzymes, Sacl and Ndel followed by gel purification. Subsequently, N- terminal region of BclB gene was amplified same as above. Amplified BclB gene was gel purified and digested with restriction enzymes- Sacl and Ndel (insert). The above insert and vector were ligated and transformed in DH5-a host cell (named as pSR2). Example 2 1. Plasmid comprising only BclA gene (pSR4, MTCC 25148): The plasmid comprising BclA genewas synthesized by GenScript in pUC19 vector between restriction sites Ndel and Sacl. BclA gene was amplified using BclA-F and BclA-R primers, followed by gel purification (insert), the same was cloned in pET29a+ between Ndel and Sacl restriction sites and named as pSR4 (depicted in Figure 2). The PCR program employed for amplification of BclA gene was: 95 °C- 3 min (initial denaturation), 95 °C- 1 min, 58 °C- 1 min, 72 °C- 1 min (30 cycles), 72 °C- 10 min (final extension).

2. Bacterial cell display system comprising BclA and DszC (pSR5, MTCC 25149): To clone BclA gene upstream to DszC, pSRl (prepared earlier) was used as vector. N- terminal region of BclA gene was amplified using BclA-F and BclA-R primers (sequence as shown in SEQ ID NO: 33 and SEQ ID NO: 34), followed by gel purification (insert). Vector and insert for BclA gene were digested with restriction enzymes- Sacl and Ndel, ligated and transformed in DH5-a host cell (named as pSR5). All the clones prepared were confirmed by colony PCR, restriction digestion analysis and DNA sequencing.

Example 3

[176] Expression and SDS PAGE analysis of DszC protein: Confirmed plasmids of pSRl (pET29a+DszC), pSR2 (pET29a+DszC+BclB) and pSR5 (pET29a+DszC+BclA) as prepared earlier, were transformed in E. coli- pLysS competent cells for protein expression. The cells were cultivated in Luria-Bertani (LB procured form HiMedia) medium, supplemented with 50 μg/ml kanamycin, at 37 °C and 180 rpm. Maximum induction was observed when the cells were induced with 1 mM isopropyl β-D-l-thiogalactopyranoside (IPTG procured from HiMedia) at an OD₆oo ~ 0.5- 0.6 and further grown at 30 °C/ 180 rpm for 2- 3 hours. Post incubation, the cells were harvested for lysate preparation. The lysate was then analyzed on 12% SDS-PAGE and stained with Coomassie dye for visualization of bands.

[177] Expression and SDS PAGE analysis of DszC protein on the surface of E. coli: To determine whether the expressed protein is displayed on the surface of E. coli, outer membrane protein fraction was isolated and analysed on an SDS-PAGE. Briefly, cells were harvested from 5 ml induced cell broth (prepared as above) by centrifugation at 3500 rpm for 5 minutes at 4 °C. Pellet thus obtained, was washed twice with lOmM Na₂HP0₄ buffer (pH 7.2). Cells were disrupted by three cycles of sonication with amplitude 20% pulse on/off 5 sees each. Partially disrupted cells were removed by centrifugation at 10000 rpm for 2 min at 4°C, post which membrane proteins and lipid layers were isolated by centrifuging at 12000 rpm for 30 min at 4°C. The pellet obtained was suspended in 0.5 ml of lOmM Na₂HP0₄buffer (pH 7.2), 0.5% (w/v) SDS was added and incubated for 30 min at 37°C. Membrane proteins were obtained by centrifugation of insoluble pellet at 10000 rpm for 30 min at 4°C. Insoluble pellet was washed with lOmM Na₂HP0₄ buffer (pH 7.2) and finally the insoluble pellet was resuspended in 50μ1 of TE (Tris-EDTA) buffer of pH 8.0, and analysed on 12% SDS- PAGE. The desired band corresponding to the displayed DszC protein was excised from the SDS gel and analysed by MALDI-ToF (Matrix Assisted Laser Desorption/Ionization- Time of flight spectrometer).

Example 4

[178] MALDI ToF Analysis of membrane expressed DszC protein: Peptide mass fingerprint was generated using trypsin In-gel digestion protocol of Bruker Daltonics. The Coomassie stained SDS gel with expression band of DszC protein was destained and washed twice with distilled water. The bands were cut into 1 mm cubes and collected in 0.5 ml microfuge tube. The gel pieces were washed with water and 50mM NH4HCO3/ acetonitrile 1+1 (v/v) solution for 15 min. Excess solution was removed and acetonitrile was added to cover the gel pieces. Excess acetonitrile and was removed and the gel pieces were rehydrated in 50 mM NH₄HC03Solution for 5 minutes. Equal volume of acetonitrile was added and incubated for 15 minutes, post which excess acetonitrile was removed. Acetonitrile was added to cover the gel pieces and removed once the shrinkage in gel pieces was observed. The gel pieces were dried down in a vacuum centrifuge. The gel pieces were incubated in lOmM dithiothreitol (DTT)/ 50mM NH₄HCo3Solution (freshly prepared) and incubated for 45 min at 56 °C for rehydration. Post incubation the tubes were chilled to room temperature. Excess solution was removed and quickly replaced with 55mM iodoacetamide in 50mM NtUHCCbsolution, and the tubes were incubated for 30 min at room temperature in dark. Excess of iodoacetamide solution was removed and the gel pieces were washed twice with 50mM NH4HCO3/ acetonitrile (1+1, v/v) solution, 15 min per change. Acetonitrile was added to cover gel pieces so that gel pieces shrink together. Excess acetonitrile was removed and the gel pieces were dried down in a vacuum centrifuge. Freshly prepared trypsin solution (25 ng/μΐ in 25mM NH4HCO3) was added to cover the gel pieces and incubated at 37 °C for 1 hour. Excess of enzyme solution was removed and 25mM NFLtHCOssolution was added and incubated at 37 °C overnight to keep the gel pieces wet. Next day, the gel plugs were covered completely with extraction buffer and incubated at room temperature for 30 minutes and excess of NH4HC03Solution was removed. Gel plugs were completely covered with extraction buffer (50/50 0.1 %TF A/ Acetonitrile) and extraction of peptides was supported by ultrasonication for few minutes to improve the extraction yields. Extracted peptide(s) were proceeded for MALDI-TOF analysis.

Example 5

The present example illustrates the use of surface displayed DszC enzyme for the conversion of dibenzothiophene to dibenzothiophene sulfone.

[179] Bio-desulphurization of dibenzothiophene (DBT): To estimate the amount of DBT (substrate)getting converted to DBT sulfone by intracellular DszC enzyme and DszC enzyme displayed on surface using BclB (SEQ ID NO: 12) or BclA (SEQ ID NO: 22), cells expressed earlier were used. Briefly, a single colony of pSRl, pSR2, and pSR5 was inoculated in 5 ml LB and grown overnight. 1% of the overnight grown culture was inoculated in 500 ml LB containing 50 μg/ml kanamycin. Cells were grown until OD₆oo reached to -0.5 and then induced with ImM IPTG. Cells were further allowed to grow at 30°C for 2 hours for expression of protein. Post incubation, the culture was supplemented with 0.5 mM NADH and 25ppm of (DBT)and incubated at 30°C, 180 rpm followed by sampling at 20 minutes' interval. Extraction was carried out and High-performance liquid chromatography (HPLC) was performed to calculate the conversion of DBT to DBT sulfone.

Example 6

[180] Effect of supplementation of NADH in the medium on conversion of DBT to DBT sulfone: NADH is required as a cofactor for DszC enzyme. Since NADH is not permeable to the cytoplasmic membrane, it was supplemented additionally for the activity of surface displayed DszC enzyme whereas, the intracellular DszC enzyme is capable of utilizing cellular supply of cofactors. In order to determine the effect of cofactor addition in media, 1% inoculum of overnight grown bacterial culture of intracellular DszC and membrane displayed DszC (as described above), was added to 300 ml Luria broth supplemented with 50 μg/ml kanamycin, 25 ppm DBT, 0.5mM NADH. The culture was grown at 37 °C, 180 rpm and the cells were induced with ImM IPTG at OD₆oo ~ 0.5. Samples were withdrawn at various time intervals followed by extraction and then detection of DBT-sulfone by HPLC.

Example 7

[181] Thin layer Chromatography (TLC): In order to demonstrate the active display of DszC enzyme on the bacterial cell surface, metabolism of DBT by desulfurizing enzyme DszC and production of metabolite after metabolism of DBT by enzyme DszC were analysed on TLC plate. Briefly, 5ml LB broth was supplemented with 50 μg/ml kanamycin, 0.135mM DBT and 0.5mM NADH. Single colony, each of pSRl (only DszC) and pSR2 (BclB+ DszC) was inoculated separately in the above broth and the cells were allowed to grow at 37 °C/ 180rpm till O.D₆oo -0.5-0.6. Once desired O.D. was attained, the cells were induced with ImM IPTG and further allowed to grow at 30 °C/ 180rpm. Samples were taken at different time points of 3 hours, 6 hours and overnight. For harvesting, sample was collected and centrifuged at 5000rpm for 5 mins, supernatant was collected in a separate falcon, and the pellet was resuspended in 5ml of sodium phosphate buffer (pH 7.2). Metabolite extraction was carried out by acidifying the culture and then extracting thrice with equal volume of ethyl acetate. Extracted metabolites were dissolved in 200μ1 of acetone: heptane ( 1 : 1). Samples were spotted on TLC plate and developed using mobile phase chloroform: toluene (1:3). Metabolite(s) were seen under normal light and under UV254 lamp.

Results of the different experiments conducted

[182] Expression and SDS PAGE analysis of DszC protein: As illustrated in example 3, SDS page analysis was performed to confirm the expression of DszC protein in supernatant and on the bacterial cell surface. Figure 2A depicts the SDS PAGE analysis of DszC protein expression in the culture of induced and uninduced samples and Figure 2B depicts the SDS PAGE analysis of DszC protein expression on the bacterial cell surface in fractionated outer membrane samples. Description of the lanes for Figure 2A and Figure 2B is provided in Table 1 and Table 2, respectively.

Table 1 (Figure 2A):

Table 2 (Figure 2B):

Note: UI is uninduced sample, I is induced sample, SN is supernatant, and OM is outer membrane Expression of DszC protein (molecular weight- ~45KDa) in supernatant of cells comprising DszC alone (amino acid sequence as shown in SEQ ID NO: 4), and BclB+ DszC (molecular weight- -48.4 lKDa and amino acid sequence as shown in SEQ ID NO: 12), and BclA+ DszC (molecular weight- ~48.8KDa and amino acid sequence as shown in SEQ ID NO: 22) can be observed in Figure 2A. Expression of protein is higher in induced samples (Lanes 2, 4 and 6) as compared to the uninduced samples (Lanes 1, 3 and 5) for all the cell supernatants, thereby confirming the induction and expression of DszC protein. In Figure 2B, expression of DszC protein is apparent in outer membrane fractions as well. For cell culture sample comprising DszC alone (pSRl), expression of the protein is higher in supernatant (Lane 2) than in the outer membrane fraction (Lane 3). Whereas, for cell culture samples comprising BclB+ DszC and BclA+ DszC, expression of protein is higher in outer membrane (Lane 6 and 9) fraction as compared to the supernatant (Lane 5 and 8). Thus, the data of SDS PAGE analysis confirms, that when anchored to BclA or BclB, there is higher expression of DszC protein on the bacterial cell surface.

[183] MALDI-ToF Analysis of membrane expressed DszC protein: Figure 3 represents the graph depicting the peptide mass fingerprint data of DszC protein obtained through MALDI-ToF technique. The procedure for the analysis is same as described in Example 4. The Mascot score is found to be significant with a score of 546, and the fingerprint matches with that of DszC protein.

[184] Bio-desulphurization of dibenzothiophene (DBT): Figure 4 depicts the HPLC data and evidences the conversion of DBT to DBT sulfone. The procedure followed is as described in example 5. Surprisingly, in case of membrane displayed DszC (BclB+ DszC and BclA+ DszC) maximum conversion of DBT to DBT sulfone is achieved in 40 minutes, whereas in case of intracellular DszC, maximum conversion is achieved in 120 minutes. Thus, the conversion of DBT to DBT sulfone is achieved 3 times faster in case of membrane displayed DszC as compared to the intracellular DszC. Additionally, the production of DBT sulfone is higher in BclB+ DszC than in BclA+ DszC. [185] Effect of supplementation of NADH in the medium on bio-desulphurization of DBT: Figure 5 represents a graph depicting the effect of NADH in the conversion of DBT to DBT sulfone. The procedure followed is as described in Example 6. It can be contemplated, that addition of NADH in the medium increases the production of DBT sulfone in case of membrane displayed DszC (BclB+ DszC) protein. Moreover, the production increases with increase in time from 2 hours to 24 hours.

[186] Thin layer chromatography: Figure 6A and 6B represent the TLC data depicting the metabolism of DBT by DszC enzyme and production of metabolite, i.e. DBT sulfone, for surface displayed DszC and intracellular DszC respectively. The procedure followed is as described in Figure 7. Description of the lanes have been provided in

Table 3.

Table 3 (Figure 6A):

10 Metabolite extracted from supernatant of surface displayed BclB+ DszC (I/overnight)

^ote: I is induced, UI is uninduced.

Table 4 (Figure 6B)

Lanes Sample

1 DBT

2 DBT sulfone

3 Metabolite extracted from pellet of intracellular DszC (UI)

4 Metabolite extracted from supernatant of intracellular DszC (UI)

5 Metabolite extracted from pellet of intracellular DszC (I/3hours)

6 Metabolite extracted from supernatant of intracellular DszC (I/3hours)

7 Metabolite extracted from pellet of intracellular DszC (I/6hours)

8 Metabolite extracted from supernatant of intracellular DszC (I/6hours)

9 Metabolite extracted from pellet of intracellular DszC (I/overnight)

10 Metabolite extracted from supernatant of intracellular DszC

(I/overnight)

^ote: I is induced, UI is uninduced.

In case of intracellular DszC (pSRl), DBT will be first transported inside the cell and upon action by DszC get converted into DBT-sulfone. Therefore, production of DBT- sulfone will first appear inside cell and then the metabolite will be transported outside the cell, as can be observed in Figure 6B, which shows presence of DBT sulfone in cell pellet as well as culture supernatant (lane 5 to lane 10). Whereas, in case of surface displayed DszC (pSR2 BclB+ DszC), there is no need of transportation of DBT inside the cell, and the production of DBT-sulfone is extracellular. This is further made evident in Figure 6A, which shows presence of DBT sulfone exclusively in the cell culture supernatant (lane 6, 8 and 10).

[187] The results obtained, ascertain the advantages achieved by expressing a desired protein on the cell surface as compared to intracellular expression of the protein. Since, presence of sulphur in fuels act as a major pollutant, the cell surface display mechanism disclosed in the present invention has huge implications in enhancing and expediting the process of bio-desulphurization. This can be achieved by expressing different enzymes or proteins playing a role in this pathway on the cell surface of bacteria followed by sequential treatment with sample.

Advantages of the present disclosure: Overall, present disclosure provides a recombinant vector comprising fusion DNA, and the fusion DNA further comprises either BclB or BclA, fused to a gene of interest wherein the fusion DNA encodes a fusion polypeptide, for the purpose of displaying the fusion polypeptide on the surface of a host cell. For the present study, the gene of interest demonstrated is DszC (encodes for enzyme for bio-desulphurization). The bacterial cell displaying the recombinant DszC protein on the surface is useful for conversion of substrate to desired product and the conversion achieved is 3 times faster when compared to intracellular DszC protein. The system can further be used for effectively displaying other intracellular enzymes on cell surface thereby reducing the time for conversion of substrates to desired products. The system can also be used for displaying proteins, ligands and antibodies on a host cell surface.

Claims

I/We Claim:

1. A recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclB, and a gene of interest, and wherein BclB having nucleotide sequence is as set forth in SEQ ID NO: 1.

2. The recombinant vector as claimed in claim 1, wherein the promoter is selected from the group consisting of T7 promoter, Tac promoter, and Trc promoter.

3. The recombinant vector as claimed in claim 1, wherein the fusion polypeptide having amino acid sequence is selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18.

4. The recombinant vector as claimed in claim 3, wherein the fusion polypeptide having amino acid sequence is as set forth in SEQ ID NO: 12

5. The recombinant vector as claimed in claim 1, wherein the gene of interest having nucleotide sequence is selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID NO: 7, and SEQ ID NO: 9.

6. The recombinant vector as claimed in claim 1 , wherein the fusion DNA is represented by SEQ ID NO: 11 , and wherein the SEQ ID NO: 11 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 3.

7. The recombinant vector as claimed in claim 1, wherein the fusion DNA is represented by SEQ ID NO: 13, and wherein the SEQ ID NO: 13 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 5.

8. The recombinant vector as claimed in claim 1, wherein the fusion DNA is represented by SEQ ID NO: 15, and wherein the SEQ ID NO: 15 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 7.

9. The recombinant vector as claimed in claim 1, wherein the fusion DNA is represented by SEQ ID NO: 17, and wherein the SEQ ID NO: 17 comprises a fusion of SEQ ID NO: 1 and SEQ ID NO: 9.

10. A recombinant host cell comprising the recombinant vector as claimed in any of the claims 1-9.

11. The recombinant host cell as claimed in claim 10, wherein the host cell is selected from the group consisting of a bacteriophage, a bacterial cell, an yeast cell, a plant cell, and a fungal cell.

12. The recombinant host cell as claimed in claim 11, wherein the host cell is a bacterial cell.

13. A bacterial cell display system comprising the recombinant vector as claimed in any of the claims 1-9.

14. A method for expressing a fusion polypeptide on a host cell surface, said method comprising: a. obtaining a recombinant host cell as claimed in any of the claims 10- 12; and b. growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein the fusion polypeptide having amino acid sequence is selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 14, SEQ ID NO: 16, and SEQ ID NO: 18.

15. A method for converting dibenzothiophene to dibenzothiophene sulfone, said method comprising: a. obtaining a sample comprising dibenzothiophene;

b. obtaining a recombinant host cell comprising the recombinant vector as claimed in claim 6; c. contacting the sample with the host cell of step (b) to obtain a mixture; and

d. incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene to dibenzothiophene sulfone

A method for converting dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate, said method comprising: a. obtaining a sample comprising dibenzothiophene sulfone;

b. obtaining a recombinant host cell comprising the recombinant vector as claimed in claim 8;

c. contacting the sample with the host cell of step (b) to obtain a mixture; and

d. incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene sulfone to hydroxyphenyl benzene sulfonate.

A method for converting hydroxyphenyl benzene sulfonate to hydroxybiphenyl, said method comprising: a. obtaining a sample comprising hydroxyphenyl benzene sulfonate; b. obtaining a recombinant host cell comprising the recombinant vector as claimed in claim 9;

d. incubating the mixture under suitable conditions for the growth of the host cell to convert hydroxyphenyl benzene sulfonate to hydroxybiphenyl.

A recombinant vector comprising a fusion DNA, and a promoter to drive the expression of the fusion DNA encoding a fusion polypeptide, wherein the fusion DNA comprises BclA, and a gene of interest, and wherein BclA having nucleotide sequence is as set forth in SEQ ID NO: 19.

19. The recombinant vector as claimed in claim 18, wherein the promoter is selected from the group consisting of T7 promoter, Tac promoter, Trc promoter.

20. The recombinant vector as claimed in claim 18, wherein the fusion polypeptide having amino acid sequence is selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO: 28.

21. The recombinant vector as claimed in claim 20, wherein the fusion polypeptide having amino acid sequence as set forth in SEQ ID NO: 22.

22. The recombinant vector as claimed in claim 18, wherein the gene of interest having nucleotide sequence is selected from the group consisting of SEQ ID NO:3, SEQ ID NO:5, SEQ ID NO:7, and SEQ ID NO:9.

23. The recombinant vector as claimed in claim 18, wherein the fusion DNA is represented by SEQ ID NO: 21, and wherein the SEQ ID NO: 21 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 3.

24. The recombinant vector as claimed in claim 18, wherein the fusion DNA is represented by SEQ ID NO: 23, and wherein the SEQ ID NO: 23 comprises a fusion of SEQ ID NO : 19 and SEQ ID NO : 5.

25. The recombinant vector as claimed in claim 18, wherein the fusion DNA is represented by SEQ ID NO: 25, and wherein the SEQ ID NO: 25 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 7.

26. The recombinant vector as claimed in claim 18, wherein the fusion DNA is represented by SEQ ID NO: 27, and wherein the SEQ ID NO: 27 comprises a fusion of SEQ ID NO: 19 and SEQ ID NO: 9.

27. A recombinant host cell comprising the recombinant vector as claimed in any of the claims 18-26.

28. The recombinant host cell as claimed in claim 27, wherein the host cell is selected from the group consisting of a bacteriophage, a bacterial cell, an yeast cell, a plant cell, and a fungal cell.

29. The recombinant host cell as claimed in claim 28, wherein the host cell is a bacterial cell.

30. A bacterial cell display system comprising the recombinant vector as claimed in any of the claims 18-26.

31. A method for expressing a fusion polypeptide on a host cell surface, said method comprising: a. obtaining a recombinant host cell as claimed in any of the claims 27- 29; and b. growing the recombinant host cell under suitable conditions for the expression of the fusion polypeptide, wherein the fusion polypeptide having amino acid sequence is selected from the group consisting of SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 26, and SEQ ID NO:

28.

32. A method for converting dibenzothiophene to dibenzothiophene sulfone, said method comprising: a. obtaining a sample comprising dibenzothiophene; b. obtaining a recombinant host cell comprising the recombinant vector as claimed in claim 23 ;

c. contacting the sample with the host cell of step (b) to obtain a mixture; and d. incubating the mixture under suitable conditions for the growth of the host cell to convert dibenzothiophene to dibenzothiophene sulfone.

b. obtaining a recombinant host cell comprising the recombinant vector as claimed in claim 25;

A method for converting to hydroxyphenyl benzene sulfonate to hydroxybiphenyl, said method comprising: a. obtaining a sample comprising hydroxyphenyl benzene sulfonate; b. obtaining a recombinant host cell comprising the recombinant vector as claimed in claim 26;

d. incubating the mixture under suitable conditions for the growth of the host cell to convert hydroxyphenyl benzene sulfonate to hydroxybiphenyl .