CN117701478A - Bacillus aerophilus for high yield of pectase and application thereof - Google Patents

Abstract

The invention relates to a bacillus acidophilus for high-yield pectase and application thereof, and the strain is classified and named as bacillus acidophilusBacillus aerophilusThe microbial strain is preserved in China general microbiological culture Collection center (China Committee for culture Collection of microorganisms) at the date of 09 and 13 of 2023, and the preservation address is the number 3 of North West Lu 1, the Korean region of Beijing, and the preservation number is CGMCC No.28453. The invention provides the bacillus acidophilusBacillus aerophilusNot only has stable inheritance of characters and higher pectase activity, but also has excellent tolerance performance, and can be applied to fruit peeling rings in high-pectin fruit processingThe peeling period can be obviously shortened, the product quality is improved, and the method has the advantages of light influence on environment, no secondary pollution, simple process, flexible mode and the like, and has good development and application prospects.

Description

Bacillus aerophilus for high yield of pectase and application thereof

Technical Field

The invention belongs to the technical field of agricultural product processing, relates to bacillus and application thereof, and in particular relates to bacillus aerophilus with high pectase yield and application thereof in peeling fruits with high pectase yield.

Background

Pectin is a natural macromolecular polysaccharide polymer formed by connecting D-galacturonic acid through alpha-1, 4-glycosidic bond, and is mainly in the form of pectin, protopectin and pectic acid commonly existing in fruits, roots, stems and leaves of plants. Pectin often coexists with cellulose to form cell wall and interlayer adhesive of plant cells, so that cells are tightly adhered, the processing process of plant fruit products is greatly influenced, the treatment efficiency is reduced, and the maintenance cost is increased.

Pectase belongs to a compound enzyme, is a generic name of enzymes capable of catalyzing and decomposing pectin, and is widely applied to the fields of fruit juice beverage, coffee, pepper peeling and the like. Although natural pectase exists widely in animals and plants in nature, the pectase has low yield and is not easy to separate, extract and purify, and is difficult to produce on a large scale. In addition, the research on pectase in China is started later, the enzyme production cost is high, large-scale production is difficult to form, the current food industry requirements cannot be met, and most pectase still needs to be imported.

With the rapid development of microbial enzyme technology, the advantages of short growth period, simple and easily controlled culture conditions, wide distribution and the like are achieved, and the microbial enzyme has become an excellent biological resource for producing pectase, and mainly comprises bacillus, mould, yeast and the like. Such microorganisms are capable of producing the corresponding pectinases to utilize such complex carbohydrates to maintain their growth and reproduction. Therefore, the related microorganism lyase can expand the application of microorganism metabolites, and has important significance in improving the processing efficiency of fruit and vegetable products.

High pectin fruits, in particular peppers, are important spices, are important commercial crops in tropical areas, and nowadays peppers are mostly introduced into the market in the form of white pepper products. However, in the pepper processing process, the peeling step of the pepper fruits is mainly treated by adopting a flowing water soaking mode, and the process is simple and easy to implement, but the peeling efficiency is low, and the produced white peppers have the defects of heavy abnormal taste, low quality, large wastewater discharge, easiness in environmental pollution and the like. At present, how to efficiently and rapidly realize peeling of high pectin fruits, simplify processing links and produce high-quality agricultural products is one of the practical problems of industrial development to be solved urgently.

Disclosure of Invention

The invention aims to provide bacillus acidophilus with high pectase yield and application thereof.

Bacillus acidophilus, classified and named as bacillus acidophilusBacillus aerophilusThe microbial strain is preserved in China general microbiological culture Collection center (China Committee for culture Collection of microorganisms) at the date of 09 and 13 of 2023, and the preservation address is the number 3 of North West Lu 1, the Korean region of Beijing, and the preservation number is CGMCC No.28453.

The invention provides the bacillus acidophilusBacillus aerophilusIn the process of soaking and peeling fresh pepper fruit water, the fruit water is screened to show the enzyme activities of polygalacturonic acid, pectin lyase, pectin esterase and the like, has tolerance to high temperature and low acid environment and to the essential oil of pepper and piperine, and has stable inheritance of the character. The 16S rDNA sequence identification shows that the strain has the similarity of over 99 percent with the corresponding sequence of the known bacillus, is a new strain of the bacillus acidophilus, and is classified and named as the bacillus acidophilusBacillus aerophilus. The morphological characteristics of the colonies on the nutrient broth are milky white in color, flat and uniform in texture and shape, opaque, neat and smooth in surface and edge, and short bars in cell morphology when observed by a microscope.

Another object of the present invention is to provide the Bacillus acidophilusBacillus aerophilusThe application in peeling fruits with high pectin is provided.

Preferably, the Gao Guojiao fruit is pepper, coffee or walnut.

Preferably, the method for peeling Gao Guojiao fruits comprises the following steps:

selecting fresh fruit with high pectin, adding pure water, and mixing with 10 ⁶ CFU/mL inoculation of Bacillus acidophilusBacillus aerophilusSoaking seed liquid in water, peeling, and ventilating once every day; and after the soaking is finished, cleaning and removing impurities to obtain a peeled product, and drying to obtain the product.

Preferably, the mass ratio of the pure water to the fruits is as follows: 3:1-2 (W/W).

Preferably, the bacillus acidophilusBacillus aerophilusThe preparation steps of the seed liquid are as follows:

bacillus aerophilusBacillus aerophilusInoculating 1-5% of the seed liquid into a nutrient broth culture medium, and culturing the seed liquid in a biochemical incubator at 35-38 ℃ for 10-15 h.

Preferably, the drying is carried out by heating at 60-70 ℃ until the water content of the product is lower than 15%.

Compared with the prior art, the invention has the following effects:

the invention provides the bacillus acidophilusBacillus aerophilusIn the process of soaking and peeling fresh pepper fruits by water, the screening method has stable and inherited properties, higher pectase activity, excellent tolerance performance, normal growth at 30-40 ℃, good tolerance under the condition of low pH (pH=5), application in fruit processing with high pectin, obvious shortening of peeling period, improvement of product quality, light influence on environment, no secondary pollution, simple process, flexible mode and the like, and has good development and application prospects.

Drawings

FIG. 1 Bacillus aerophilusBacillus aerophilusColony characterization.

FIG. 2 Bacillus aerophilusBacillus aerophilusStrain morphology.

FIG. 3 Bacillus aerophilusBacillus aerophilusA growth curve graph.

FIG. 4 temperature vs. Bacillus acidophilusBacillus aerophilusAnd (5) a graph of the effect of growth and enzyme activity.

FIG. 5 pH against Bacillus acidophilusBacillus aerophilusAnd (5) a graph of the effect of growth and enzyme activity.

FIG. 6 essential oil vs. Bacillus acidophilusBacillus aerophilusAnd (5) a graph of the effect of growth and enzyme activity.

FIG. 7 piperine vs. Bacillus acidophilusBacillus aerophilusAnd (5) a graph of the effect of growth and enzyme activity.

FIG. 8 Peel rate variation during peeling of pepper fruit water.

FIG. 9 changes in enzyme activity and pH during peeling of pepper fruit water.

Fig. 10 changes in the microstructure of the skin of pepper in natural water.

FIG. 11 Pepper seed water immersion epidermal microstructure change.

FIG. 12 inoculation is compared to naturally soaked white pepper volatiles.

Detailed Description

The following describes the embodiments of the present invention in further detail with reference to examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention. The experimental methods, in which specific conditions are not noted in the following examples, are generally conducted under conventional conditions or under conditions recommended by the manufacturer. Materials, reagents, and the like used in the examples described below are commercially available with analytically pure reagents as preferred reagents unless otherwise specified.

EXAMPLE 1 isolation of strains

Soaking fresh fructus Piperis in water, peeling, taking soaking water sample every day, gradient diluting, and coating pectin agar medium (5 g/L pectin, 10 g/L peptone, 6 g/L K) with 3 proper gradients ₂ HPO ₄ 、2g/L KH ₂ PO ₄ 、0.1g/L MgSO ₄ 2g/L yeast extract, 20g/L agar), then placing all the plates into a constant temperature incubator at 37 ℃ for inverted culture for 3-5 d, after macroscopic colonies are grown, streaking and purifying the single colonies, observing and recording the colors of the coloniesAnd morphological characteristics, and performing microscopic examination to obtain pure seeds, and then preserving by using a glycerol freeze preservation method. Mixing sterilized 50% glycerol with bacterial liquid obtained by pure culture at a ratio of 1:1 (V/V), and freezing and storing in a refrigerator at-80deg.C.

In total, 50 different types of strains were isolated, and the strains were further screened to obtain strains having pectase activity.

EXAMPLE 2 screening of strains

(1) And (3) primary screening: after the isolated strain is activated, the strain is inoculated on a plate of pectin agar medium and cultured for 3-5 d at 28 ℃. The diameter (D) of a single colony is measured by a vernier caliper, a pectin flat plate is dyed by a Congo red dyeing method, the size of a transparent ring is observed and recorded, the diameter of the transparent ring is D, the diameter of the colony is D, and the value of D/D is obtained. The dyeing method is that Congo red dye liquor is poured on a pectin flat plate with single colony and goes beyond the blank of the flat plate, after dyeing for 20 min, 1 mol/L NaCl washing liquor is poured on the flat plate for 20 min, then the washing liquor is poured off, and the washing is repeated once.

The Congo red dye liquor is as follows: congo red dyeing reagent 7.000 and g are weighed, dissolved and distilled water is fixed to volume of 1L, and 1 mol/L dye liquor is prepared.

(2) And (3) re-screening: the strain screened at first is re-screened, and after the strain is activated, the strain is inoculated into a nutrition broth of 100 mL with an inoculum size of 1 percent, and is cultured at 37 ℃ for 3d, and the activity of pectase produced by the strain is measured by a DNS method. Taking 1 mL fermentation liquor, centrifuging at 10000 r/min and 4 ℃ for 5min, and taking supernatant to dilute by a proper factor as crude enzyme liquid. The enzyme activity group and the inactivation group are 2 groups, and each group is numbered A and B. 2.5 mL of 1.0% pectin solution is added to each test tube, the mixture is preheated in a water bath at 50 ℃ for 5min, 0.5 mL crude enzyme solution is added to the A tube, 0.5 mL inactivated crude enzyme solution (boiling water bath for 5 min) is added to the B tube, and the test tubes are all placed in a water bath at 50 ℃ for 30 min for reaction. 1.0 mL of DNS reagent is added to the reaction solution of mL in a test tube, and the reaction solution is bathed in boiling water for 10 min. Taking out, rapidly cooling to room temperature, adding distilled water for dilution by a proper multiple, shaking, measuring an OD value at 540 and nm, and calculating an enzyme activity formula:

a: enzyme-like absorbance; a is that ₀ : enzyme blank absorbance; n: dilution of enzyme solution; 3: when the enzyme activity is measured, 1/3 of the reaction liquid is taken; 1000:1 mg of D-galacturonic acid is 1000. Mu.g; k: slope of the standard curve; t: reaction time.

The 1.0% pectin solution is: 1 g/L pectin substrate is prepared by using buffer solution of citric acid-disodium hydrogen phosphate with pH of 5, and the pectin substrate is preserved at 4 ℃ for 3 days.

The DNS reagent is as follows: taking 3, 5-dinitrosalicylic acid 10 g, adding 2 mol/L sodium hydroxide solution 200 mL, dissolving 3, 5-dinitrosalicylic acid, then adding potassium sodium tartrate 300 g, diluting to 2000 mL with deionized water until the solution is completely dissolved, and preserving in a brown bottle.

Congo red is used as a dye, can be combined with macromolecular polysaccharide to form a red compound, but not with disaccharide and monosaccharide, and after pectase secreted in a culture medium around a colony is used for degrading polysaccharide pectin into micromolecular sugar, naCl washing liquid can wash out the loosely-combined pectin, transparent rings can appear around the colony, and the higher the D/D value is, the higher the enzyme activity is. 10 strains are screened out according to the D/D value to carry out the next re-screening.

Pectin is used as a substrate, fermentation liquor is used as crude enzyme liquor, and the reaction is carried out for 30 min at a certain temperature. The enzymatic activity was calculated by measuring the galacturonic acid content by DNS method using galacturonic acid as a reaction product. The enzyme activity unit is defined as: hydrolysis of pectin at 50℃and pH 5.0 per minute yields 1. Mu.g galacturonic acid as one enzyme activity unit (U). The results are shown in Table 1, and the results show that only part of bacillus has certain pectase activity, and the pectase activity difference of different strains is obvious, especially the enzyme activity of the strain P01 is as high as 2.73U/mL, and the strains J08, J20, P09 and P25 also have certain enzyme activity, but are relatively low, so that the strain P01 is selected for the previous study.

TABLE 1 enzyme Activity of strains

The colony morphology of strain P01 on nutrient broth is shown in FIGS. 1 and 2. As can be seen from the figure, the Bacillus aerophilusBacillus aerophilusThe morphological characteristics of the bacterial colony on the nutrient broth culture medium are milky white, flat and uniform in texture and shape, opaque, and neat and smooth in surface and edge; and the cell morphology was observed by a microscope in a short bar shape.

Example 3 identification of strains

The strain P01 DNA is extracted by adopting an Ezup column type bacterial genome DNA extraction kit (refer to a product instruction book), and is preserved at the temperature of minus 20 ℃ for standby. The target fragment of the PCR product was recovered using a gel recovery kit and sent to the Shanghai Co., ltd for gene sequencing.

A homology search was performed in the GenBank nucleotide sequence database (https:// BLAST. Ncbi. Nlm. Nih. Gov/BLAST. Cgi) using BLAST software, and the test strain (strain P01) was compared with the corresponding sequences of known Bacillus, and the species of Bacillus of the test strain was identified by comparison with the corresponding sequences of known Bacillus (the degree of similarity was considered to be the same species at 99% or more). The identification result shows that the similarity of the tested strain (strain P01) and the corresponding sequence of the known bacillus is over 99 percent, and the strain is a new strain of the bacillus.

Strain P01 was designated as Bacillus acidophilusBacillus aerophilus(hereinafter referred to as strain P01), the preservation number is CGMCC NO.28453, and the 16S rDNA gene sequence is shown as SEQ ID NO. 1.

SEQ ID NO.1 sequence: TGGCCAAGGCTAGCTGACGACGTAGATTAGAGTCTGAGCGTGACGAGAAGGAGAGCTTGCTCCCGGATGTTAGCGGCGGACGGGTGAGTAACACGTGGGTAACCTGCCTGTAAGACTGGGATAACTCCGGGAAACCGGAGCTAATACCGGATAGTTCCTTGAACCGCATGGTTCAAGGATGAAAGACGGTTTCGGCTGTCACTTACAGATGGACCCGCGGCGCATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCGACGATGCGTAGCCGACCTGAGAGGGTGATCGGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCGCAATGGACGAAAGTCTGACGGAGCAACGCCGCGTGAGTGATGAAGGTTTTCGGATCGTAAAGCTCTGTTGTTAGGGAAGAACAAGTGCAAGAGTAACTGCTTGCACCTTGACGGTACCTAACCAGAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAAGCGTTGTCCGGAATTATTGGGCGTAAAGGGCTCGCAGGCGGTTTCTTAAGTCTGATGTGAAAGCCCCCGGCTCAACCGGGGAGGGTCATTGGAAACTGGGAAACTTGAGTGCAGAAGAGGAGAGTGGAATTCCACGTGTAGCGGTGAAATGCGTAGAGATGTGGAGGAACACCAGTGGCGAAGGCGACTCTCTGGTCTGTAACTGACGCTGAGGAGCGAAAGCGTGGGGAGCGAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGAGTGCTAAGTGTTAGGGGGTTTCCGCCCCTTAGTGCTGCAGCTAACGCATTAAGCACTCCGCCTGGGGAGTACGGTCGCAAGACTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTCTGACAACCCTAGAGATAGGGCTTTCCCTTCGGGGACAGAGTGACAGGTGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTGATCTTAGTTGCCAGCATTCAGTTGGGCACTCTAAGGTGACTGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGACAGAACAAAGGGCTGCGAGACCGCAAGGTTTAGCCAATCCCACAAATCTGTTCTCAGTTCGGATCGCAGTCTGCAACTCGACTGCGTGAAGCTGGAATCGCTAGTAATCGCGGATCAGCATGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCACGAGAGTTTGCAACACCCGAAGTCGGTGAGGTAACCTCTATGGTAACAGCGACTAGCAGGAGTTCTGCTC.

EXAMPLE 4 Strain P01 growth Curve

Growth curve of strain P01: strain P01 was grown at 10 ⁶ Inoculating CFU/mL into 200 mL nutrient broth, standing at 37deg.C, culturing, and measuring OD of the culture solution at regular intervals _600nm Bacillus growth curves were plotted as shown in fig. 3. Over time, strain P01 has the strongest growth capacity, strain P01 has a shorter lag phase, less than 2 h; 2-12 hours basically enter a logarithmic growth phase, the strain grows rapidly at the moment, the growth rate of the strain is obviously higher than the death rate, and the activity of the strain is high at the moment and is suitable for inoculation liquid; 12 After h the stationary phase was entered and the strain had begun to enter the recession phase at a separate temperature after 36 h. Thus, the strain was determined to be suitable for an inoculation time of 10 h and a "harvest" time of 24 hours.

EXAMPLE 5 evaluation of growth characteristics of Strain P01

Tolerance study of strain P01, 10% of activated seed solution ⁶ The CFU/mL inoculum size was inoculated in 50 mL treatments (including different temperatures, pH and concentrations of piper essential oil and piperine)The nutrient broth culture medium of the strain is subjected to stationary culture at 37 ℃ for 48 h, OD value at 600 nm and pectase activity of fermentation broth are measured, and three experimental settings are repeated to further evaluate the performances of the strain, such as temperature tolerance, essential oil tolerance, piperine tolerance, pH tolerance and the like.

Although the strain P01 is isolated from the soaking process of peppers, it is inevitably stressed by various environmental factors, such as temperature and pH, and essential oils of peppers themselves and piperine, which are most common. These environmental stresses may affect the quality of white pepper by inhibiting the growth metabolism of the strain, resulting in prolonged or even stagnant peeling time. Thus, the temperature, pH and tolerance of essential oil and piperine were studied for strain P01, and the results are shown in FIGS. 4-7.

As can be seen from the figure, strain P01 grows slower in a high temperature environment at 50 ℃ than at other temperatures, and the pectase activity is relatively low, however, the growth rate and the enzyme activity gradually increase with the decrease of the temperature, and especially reach the maximum at 30 ℃; the pH has remarkable influence on the growth and enzyme activity of the strain P01, and the growth state of the strain is relatively good at the pH=5; when the concentration of the essential oil is 0.05%, the growth vigor of the P01 is relatively good, but with the continuous increase of the use amount of the essential oil, the growth of the strain P01 is inhibited, the content of the essential oil of the pepper is 0.01-0.01%, and the strain P01 can still adapt to the environment; strain P01 was sensitive to piperine at concentrations above 0.05%.

In conclusion, the strain P01 provided by the invention can be well suitable for various adversity stress problems in the pepper soaking process, and has a good application prospect.

EXAMPLE 6 Effect of Strain P01 on Peel removal of Piper Peel

Test group (inoculation soak): selecting fresh fructus Piperis, adding 3 times of pure water, and mixing with 10 times of pure water ⁶ Seed solution of strain P01 was inoculated in an amount of CFU/mL (seed solution was obtained by inoculating strain P01 in an amount of 1% to 100 mL nutrient broth, and culturing 12 h in a biochemical incubator at 37 ℃) and was subjected to water soaking and peeling, and ventilation was carried out once a day; after soaking, cleaning and removing impurities to obtain peeled pepper particles, and drying at 60-70 ℃ to enable the pepper particles to containThe water content is lower than 12-15%, and the white pepper is obtained.

Conventional treatment group (natural soak): selecting fresh fructus Piperis, soaking in 3 times of pure water for peeling, and ventilating once every day; and after the soaking is finished, cleaning and removing impurities to obtain peeled pepper particles, and drying at 60-70 ℃ to ensure that the water content of the pepper particles is lower than 12-15%, thus obtaining the white pepper.

Measuring peeling rate, pH, enzyme activity, white pepper whiteness, hardness, essential oil, piperine, volatile compounds and sensory evaluation.

The results of physicochemical indexes in the peeling process of the pepper inoculated with the strain P01 are shown in Table 2, and the white pepper shows obvious advantages compared with the conventional treatment group in the test group.

TABLE 2 basic physicochemical results during Peel removal of Pepper

Project

L*

a*

b*

Essential oil content (mL/100 g)

Piperine content (%)

Sensory score (score)

Inoculating and soaking

47.96±0.64

4.59±0.13

14.50±0.33

2.02±0.23

4.99±0.15

5.10±1.37

Naturally soaking

44.02±0.05

6.10±0.19

18.38±0.36

1.48±0.25

4.65±0.23

3.30±1.25

Referring to fig. 8-11, as shown in fig. 8-9, the peeling rate of pepper fruits after inoculation of strain P01 (inoculation soaking) is significantly faster than that of the conventional treatment group (natural soaking), and the peeling rate after 4d is over 80%, which indicates that the peeling period of pepper fruits can be significantly shortened after inoculation of strain P01. And with the apparent mounting of the epidermis of the soaked pepper fruit, the epidermis microstructure of the fresh pepper fruit is shown in figures 10- (a) and 11- (a), and the cell structure of the pepper fruit pulp and some sub-microstructures can be clearly seen in the figures, so that the cell structure is relatively complete; while as the water soaking proceeds, the pulp structure of pepper inoculated with strain P01 became uneven after day 4, some of the basic structures of plant cells were destroyed, the intracellular structures were broken, and the pulp tissue was all disintegrated and pulped (fig. 11- (b)). The pH values of the test group (inoculation soaking) and the conventional treatment group (natural soaking) are in a descending trend, the pH value of the strain P01 is rapidly reduced after inoculation, the strain P01 is kept stable (the pH value is 5.5) after 3d, and the pH action range of pectase is 2.5-6, so that the strain P is better suitable for the pectase to play a role in the pH environment. Meanwhile, compared with the two treatment modes, the white pepper essential oil and piperine content are not obviously different, and the whiteness value of the white pepper is obviously improved. Therefore, the strain P01 provided by the invention has a great application prospect in the production and processing of white pepper.

The sensory evaluation consisted of 10 sensory panelists, and before the experiment, trained panelists scored according to the reference criteria, with the result taking the average of the 10 scores. The sensory evaluation reference criteria were: the spicy taste of the pepper is prominent and has no peculiar smell of 6-9 minutes, the spicy taste of the pepper is flat and light and has slight peculiar smell of 4-5 minutes, the spicy taste of the pepper is insufficient and the peculiar smell is intense of 1-3 minutes. The sensory evaluation results of the white peppers in different treatment modes are shown in Table 3, the sensory scores of the white peppers in different treatment modes are obvious, and compared with the conventional treatment groups, the score of the test group is higher, so that the peculiar smell of the white peppers is obviously reduced, and the score of the conventional treatment group is lower, so that the peculiar smell is heavier. Research shows that the peculiar smell of white pepper is mainly caused by the substances of the excrement and the stink such as 3-methylindole, methylphenol and the like.

TABLE 3 treatment of off-flavors and odor intensity of white pepper

The difference of the volatile matters of the white pepper in the two processing modes is compared by adopting ion mobility chromatography (GC-IMS), as shown in figure 12, the difference of the volatile matters of the white pepper obtained by inoculation soaking and natural soaking is obvious, and 51 volatile compounds are primarily identified. Compared with natural soaking, the inoculation soaking has relatively low abundance of partial substances, but relatively high abundance of characteristic aroma substances in peppers such as 2-alcohol, beta-pinene, beta-ocimene, terpinene, alpha-terpineol, phenylacetaldehyde and the like. The natural soaking white pepper is characterized by that the substances of butyric acid, isovaleric acid and methyl phenol are highlighted, and the researches show that these substances are main substances for making the white pepper produce "fecal odor and butyric acid odor". Further, according to the detection of GC-MS, the main peculiar smell substances are 3-methylindole, 4-methylphenol, phenol, 3-methylphenol, isobutyric acid, butyric acid, valeric acid and other peculiar smell substances, wherein the 3-methylindole and the 4-methylphenol are the main volatile substances which are reflected in white pepper and have fecal odor, and compared with a natural soaking group, the content of the main peculiar smell substances is obviously reduced; in addition, valeric acid and isobutyric acid, which can produce sweat malodour, were not detected in the inoculated soaked white pepper. From this, it is further demonstrated from a matter point of view that the strain P01 is effective in reducing the generation of off-flavor of pepper and accelerating the peeling process.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims (7)

1. Bacillus acidophilus, classified and named as bacillus acidophilusBacillus aerophilusThe microbial strain is preserved in China general microbiological culture Collection center (CGMCC) with a preservation address of No.1, no. 3, and a preservation number of CGMCC No.28453.

2. The bacillus acidophilus of claim 1Bacillus aerophilusThe application in peeling fruits with high pectin is provided.

3. The use according to claim 2, wherein the Gao Guojiao fruit is pepper, coffee or walnut.

4. The use according to claim 2, wherein the method of peeling Gao Guojiao fruit comprises the steps of:

selecting fresh fruit with high pectin, adding pure water, and mixing with 10 ⁶ CFU/mL inoculation of Bacillus acidophilusBacillus aerophilusSoaking seed liquid in water, peeling, and ventilating once every day; and after the soaking is finished, cleaning and removing impurities to obtain a peeled product, and drying to obtain the product.

5. The use according to claim 4, wherein the mass ratio of pure water to fruit is: 3:1-2.

6. The use according to claim 4, wherein the Bacillus acidophilus comprisesBacillus aerophilusThe preparation steps of the seed liquid are as follows:

bacillus aerophilusBacillus aerophilusInoculating 1-5% of the seed liquid into a nutrient broth culture medium, and culturing the seed liquid in a biochemical incubator at 35-38 ℃ for 10-15 h.

7. The use according to claim 4, wherein the drying is carried out by heating at 60-70 ℃ to a water content of the product below 15%.