WO2023038057A1 - ラクターゼ、ラクターゼ製剤、遺伝子、組み換えベクターおよび形質転換体 - Google Patents
ラクターゼ、ラクターゼ製剤、遺伝子、組み換えベクターおよび形質転換体 Download PDFInfo
- Publication number
- WO2023038057A1 WO2023038057A1 PCT/JP2022/033563 JP2022033563W WO2023038057A1 WO 2023038057 A1 WO2023038057 A1 WO 2023038057A1 JP 2022033563 W JP2022033563 W JP 2022033563W WO 2023038057 A1 WO2023038057 A1 WO 2023038057A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lactase
- milk
- protein
- less
- lactose
- Prior art date
Links
- 108010005774 beta-Galactosidase Proteins 0.000 title claims abstract description 219
- 102100026189 Beta-galactosidase Human genes 0.000 title claims abstract description 215
- 108010059881 Lactase Proteins 0.000 title claims abstract description 215
- 229940116108 lactase Drugs 0.000 title claims abstract description 197
- 238000002360 preparation method Methods 0.000 title claims abstract description 36
- 108090000623 proteins and genes Proteins 0.000 title claims description 73
- 239000013598 vector Substances 0.000 title claims description 13
- GUBGYTABKSRVRQ-QKKXKWKRSA-N Lactose Natural products OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O GUBGYTABKSRVRQ-QKKXKWKRSA-N 0.000 claims abstract description 109
- 239000008101 lactose Substances 0.000 claims abstract description 108
- 235000013336 milk Nutrition 0.000 claims abstract description 99
- 210000004080 milk Anatomy 0.000 claims abstract description 99
- 239000008267 milk Substances 0.000 claims abstract description 98
- 230000000694 effects Effects 0.000 claims abstract description 79
- 102000004169 proteins and genes Human genes 0.000 claims description 50
- 235000018102 proteins Nutrition 0.000 claims description 49
- 235000002639 sodium chloride Nutrition 0.000 claims description 36
- 150000003839 salts Chemical class 0.000 claims description 25
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 20
- 108020004414 DNA Proteins 0.000 claims description 18
- FWMNVWWHGCHHJJ-SKKKGAJSSA-N 4-amino-1-[(2r)-6-amino-2-[[(2r)-2-[[(2r)-2-[[(2r)-2-amino-3-phenylpropanoyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]piperidine-4-carboxylic acid Chemical compound C([C@H](C(=O)N[C@H](CC(C)C)C(=O)N[C@H](CCCCN)C(=O)N1CCC(N)(CC1)C(O)=O)NC(=O)[C@H](N)CC=1C=CC=CC=1)C1=CC=CC=C1 FWMNVWWHGCHHJJ-SKKKGAJSSA-N 0.000 claims description 14
- 239000002773 nucleotide Substances 0.000 claims description 13
- 125000003729 nucleotide group Chemical group 0.000 claims description 13
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 12
- 239000000872 buffer Substances 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 239000011780 sodium chloride Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 235000020185 raw untreated milk Nutrition 0.000 claims description 10
- 239000002994 raw material Substances 0.000 claims description 9
- 239000007787 solid Substances 0.000 claims description 9
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 claims description 8
- 239000001103 potassium chloride Substances 0.000 claims description 6
- 235000011164 potassium chloride Nutrition 0.000 claims description 6
- 239000003381 stabilizer Substances 0.000 claims description 6
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 4
- 239000001110 calcium chloride Substances 0.000 claims description 4
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 4
- 229910001629 magnesium chloride Inorganic materials 0.000 claims description 4
- 230000000295 complement effect Effects 0.000 claims description 3
- 239000000546 pharmaceutical excipient Substances 0.000 claims description 3
- 239000003755 preservative agent Substances 0.000 claims description 3
- 239000000375 suspending agent Substances 0.000 claims description 3
- 102000014171 Milk Proteins Human genes 0.000 claims description 2
- 108010011756 Milk Proteins Proteins 0.000 claims description 2
- 235000021239 milk protein Nutrition 0.000 claims description 2
- 125000003275 alpha amino acid group Chemical group 0.000 claims 6
- 230000009471 action Effects 0.000 abstract description 8
- 238000006731 degradation reaction Methods 0.000 abstract description 8
- 230000015556 catabolic process Effects 0.000 abstract description 7
- 239000000243 solution Substances 0.000 description 48
- 108090000790 Enzymes Proteins 0.000 description 44
- 102000004190 Enzymes Human genes 0.000 description 44
- 229940088598 enzyme Drugs 0.000 description 44
- 238000000354 decomposition reaction Methods 0.000 description 29
- 238000000034 method Methods 0.000 description 25
- 150000001413 amino acids Chemical group 0.000 description 20
- 238000006243 chemical reaction Methods 0.000 description 20
- 239000000203 mixture Substances 0.000 description 18
- 235000021255 galacto-oligosaccharides Nutrition 0.000 description 17
- 238000004458 analytical method Methods 0.000 description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 12
- 238000009472 formulation Methods 0.000 description 12
- 150000003271 galactooligosaccharides Chemical class 0.000 description 12
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 12
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 10
- 238000000855 fermentation Methods 0.000 description 10
- 230000004151 fermentation Effects 0.000 description 10
- 239000008103 glucose Substances 0.000 description 10
- 229910021380 Manganese Chloride Inorganic materials 0.000 description 9
- GLFNIEUTAYBVOC-UHFFFAOYSA-L Manganese chloride Chemical compound Cl[Mn]Cl GLFNIEUTAYBVOC-UHFFFAOYSA-L 0.000 description 9
- 238000004128 high performance liquid chromatography Methods 0.000 description 9
- 239000011565 manganese chloride Substances 0.000 description 9
- 235000002867 manganese chloride Nutrition 0.000 description 9
- 229940099607 manganese chloride Drugs 0.000 description 9
- 239000000523 sample Substances 0.000 description 9
- KUWPCJHYPSUOFW-YBXAARCKSA-N 2-nitrophenyl beta-D-galactoside Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@H]1OC1=CC=CC=C1[N+]([O-])=O KUWPCJHYPSUOFW-YBXAARCKSA-N 0.000 description 8
- 150000001768 cations Chemical class 0.000 description 8
- 239000000843 powder Substances 0.000 description 8
- 239000012064 sodium phosphate buffer Substances 0.000 description 8
- 239000007853 buffer solution Substances 0.000 description 7
- 150000002500 ions Chemical class 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 241001608472 Bifidobacterium longum Species 0.000 description 6
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- 229940009291 bifidobacterium longum Drugs 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 5
- 235000015140 cultured milk Nutrition 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 239000002609 medium Substances 0.000 description 5
- -1 trisaccharide galacto-oligosaccharide Chemical class 0.000 description 5
- 241001138401 Kluyveromyces lactis Species 0.000 description 4
- 101710088949 Probable beta-galactosidase B Proteins 0.000 description 4
- 102000005936 beta-Galactosidase Human genes 0.000 description 4
- 235000020247 cow milk Nutrition 0.000 description 4
- 238000012217 deletion Methods 0.000 description 4
- 230000037430 deletion Effects 0.000 description 4
- 238000000909 electrodialysis Methods 0.000 description 4
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- 230000001954 sterilising effect Effects 0.000 description 4
- 238000004659 sterilization and disinfection Methods 0.000 description 4
- WXHLLJAMBQLULT-UHFFFAOYSA-N 2-[[6-[4-(2-hydroxyethyl)piperazin-1-yl]-2-methylpyrimidin-4-yl]amino]-n-(2-methyl-6-sulfanylphenyl)-1,3-thiazole-5-carboxamide;hydrate Chemical compound O.C=1C(N2CCN(CCO)CC2)=NC(C)=NC=1NC(S1)=NC=C1C(=O)NC1=C(C)C=CC=C1S WXHLLJAMBQLULT-UHFFFAOYSA-N 0.000 description 3
- 238000009010 Bradford assay Methods 0.000 description 3
- 108091028043 Nucleic acid sequence Proteins 0.000 description 3
- 238000002835 absorbance Methods 0.000 description 3
- 230000004913 activation Effects 0.000 description 3
- 125000000539 amino acid group Chemical group 0.000 description 3
- 235000011148 calcium chloride Nutrition 0.000 description 3
- 238000005119 centrifugation Methods 0.000 description 3
- 235000013365 dairy product Nutrition 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 210000000936 intestine Anatomy 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 235000011147 magnesium chloride Nutrition 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 244000005700 microbiome Species 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- CSRCBLMBBOJYEX-UHFFFAOYSA-M sodium;2-morpholin-4-ylethanesulfonic acid;hydroxide Chemical compound [OH-].[Na+].OS(=O)(=O)CCN1CCOCC1 CSRCBLMBBOJYEX-UHFFFAOYSA-M 0.000 description 3
- 238000013112 stability test Methods 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000006228 supernatant Substances 0.000 description 3
- 229910021642 ultra pure water Inorganic materials 0.000 description 3
- 239000012498 ultrapure water Substances 0.000 description 3
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 2
- HNSDLXPSAYFUHK-UHFFFAOYSA-N 1,4-bis(2-ethylhexyl) sulfosuccinate Chemical compound CCCCC(CC)COC(=O)CC(S(O)(=O)=O)C(=O)OCC(CC)CCCC HNSDLXPSAYFUHK-UHFFFAOYSA-N 0.000 description 2
- ODDPRQJTYDIWJU-UHFFFAOYSA-N 3'-beta-D-galactopyranosyl-lactose Natural products OC1C(O)C(O)C(CO)OC1OC1C(O)C(OC2C(OC(O)C(O)C2O)CO)OC(CO)C1O ODDPRQJTYDIWJU-UHFFFAOYSA-N 0.000 description 2
- 241000193830 Bacillus <bacterium> Species 0.000 description 2
- 241000186000 Bifidobacterium Species 0.000 description 2
- 241000186016 Bifidobacterium bifidum Species 0.000 description 2
- 241000283690 Bos taurus Species 0.000 description 2
- 241000588724 Escherichia coli Species 0.000 description 2
- DHMQDGOQFOQNFH-UHFFFAOYSA-N Glycine Chemical compound NCC(O)=O DHMQDGOQFOQNFH-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 241000186673 Lactobacillus delbrueckii Species 0.000 description 2
- 201000010538 Lactose Intolerance Diseases 0.000 description 2
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 2
- 239000005862 Whey Substances 0.000 description 2
- 102000007544 Whey Proteins Human genes 0.000 description 2
- 108010046377 Whey Proteins Proteins 0.000 description 2
- 239000004480 active ingredient Substances 0.000 description 2
- FYGDTMLNYKFZSV-ANKSBSNASA-N alpha-D-Gal-(1->4)-beta-D-Gal-(1->4)-D-Glc Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@@H]1O[C@H]1[C@@H](CO)O[C@@H](O[C@@H]2[C@H](OC(O)[C@H](O)[C@H]2O)CO)[C@H](O)[C@H]1O FYGDTMLNYKFZSV-ANKSBSNASA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- ODDPRQJTYDIWJU-OAUIKNEUSA-N beta-D-Galp-(1->3)-beta-D-Galp-(1->4)-beta-D-Glcp Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@H]1O[C@@H]1[C@@H](O)[C@H](O[C@@H]2[C@H](O[C@@H](O)[C@H](O)[C@H]2O)CO)O[C@H](CO)[C@@H]1O ODDPRQJTYDIWJU-OAUIKNEUSA-N 0.000 description 2
- 229940002008 bifidobacterium bifidum Drugs 0.000 description 2
- 239000012148 binding buffer Substances 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000011088 calibration curve Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 238000000502 dialysis Methods 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 239000012149 elution buffer Substances 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000013613 expression plasmid Substances 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 239000003456 ion exchange resin Substances 0.000 description 2
- 229920003303 ion-exchange polymer Polymers 0.000 description 2
- 239000004310 lactic acid Substances 0.000 description 2
- 235000014655 lactic acid Nutrition 0.000 description 2
- 235000020190 lactose-free milk Nutrition 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 238000009928 pasteurization Methods 0.000 description 2
- 239000008363 phosphate buffer Substances 0.000 description 2
- 239000013600 plasmid vector Substances 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 239000001632 sodium acetate Substances 0.000 description 2
- 235000017281 sodium acetate Nutrition 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- QKNYBSVHEMOAJP-UHFFFAOYSA-N 2-amino-2-(hydroxymethyl)propane-1,3-diol;hydron;chloride Chemical compound Cl.OCC(N)(CO)CO QKNYBSVHEMOAJP-UHFFFAOYSA-N 0.000 description 1
- 208000004998 Abdominal Pain Diseases 0.000 description 1
- 229920000936 Agarose Polymers 0.000 description 1
- 241000228212 Aspergillus Species 0.000 description 1
- 240000006439 Aspergillus oryzae Species 0.000 description 1
- 235000002247 Aspergillus oryzae Nutrition 0.000 description 1
- 241000193752 Bacillus circulans Species 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- 101710168454 Beta-galactosidase A Proteins 0.000 description 1
- 241000555281 Brevibacillus Species 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 241000283707 Capra Species 0.000 description 1
- 241000206601 Carnobacterium mobile Species 0.000 description 1
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 description 1
- FBPFZTCFMRRESA-JGWLITMVSA-N D-glucitol Chemical compound OC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-JGWLITMVSA-N 0.000 description 1
- 206010012735 Diarrhoea Diseases 0.000 description 1
- 241000194033 Enterococcus Species 0.000 description 1
- 241000588722 Escherichia Species 0.000 description 1
- 241001198387 Escherichia coli BL21(DE3) Species 0.000 description 1
- 241000206602 Eukaryota Species 0.000 description 1
- 239000004471 Glycine Substances 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 241000235649 Kluyveromyces Species 0.000 description 1
- 235000014663 Kluyveromyces fragilis Nutrition 0.000 description 1
- 241000186781 Listeria Species 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 241001494479 Pecora Species 0.000 description 1
- 241000228143 Penicillium Species 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 101710088942 Probable beta-galactosidase A Proteins 0.000 description 1
- 101710088943 Probable beta-galactosidase C Proteins 0.000 description 1
- 102000007056 Recombinant Fusion Proteins Human genes 0.000 description 1
- 108010008281 Recombinant Fusion Proteins Proteins 0.000 description 1
- 241000235070 Saccharomyces Species 0.000 description 1
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 1
- 244000253911 Saccharomyces fragilis Species 0.000 description 1
- 235000018368 Saccharomyces fragilis Nutrition 0.000 description 1
- 241000191940 Staphylococcus Species 0.000 description 1
- 241000187747 Streptomyces Species 0.000 description 1
- 108020005038 Terminator Codon Proteins 0.000 description 1
- 241000223259 Trichoderma Species 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 238000003556 assay Methods 0.000 description 1
- 230000037429 base substitution Effects 0.000 description 1
- 239000006172 buffering agent Substances 0.000 description 1
- 235000015155 buttermilk Nutrition 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000004440 column chromatography Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000006071 cream Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 230000002255 enzymatic effect Effects 0.000 description 1
- 238000006911 enzymatic reaction Methods 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 230000002068 genetic effect Effects 0.000 description 1
- 239000001963 growth medium Substances 0.000 description 1
- 229940094991 herring sperm dna Drugs 0.000 description 1
- 238000009396 hybridization Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- BPHPUYQFMNQIOC-NXRLNHOXSA-N isopropyl beta-D-thiogalactopyranoside Chemical compound CC(C)S[C@@H]1O[C@H](CO)[C@H](O)[C@H](O)[C@H]1O BPHPUYQFMNQIOC-NXRLNHOXSA-N 0.000 description 1
- 229940031154 kluyveromyces marxianus Drugs 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 208000024191 minimally invasive lung adenocarcinoma Diseases 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000010369 molecular cloning Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 235000019679 nutrient-rich food Nutrition 0.000 description 1
- 235000008935 nutritious Nutrition 0.000 description 1
- 239000002504 physiological saline solution Substances 0.000 description 1
- 239000013612 plasmid Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000035755 proliferation Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004730 pulsed amperometry Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000011002 quantification Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 235000020183 skimmed milk Nutrition 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000007974 sodium acetate buffer Substances 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 description 1
- 238000002415 sodium dodecyl sulfate polyacrylamide gel electrophoresis Methods 0.000 description 1
- 238000000527 sonication Methods 0.000 description 1
- 239000000600 sorbitol Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000014616 translation Effects 0.000 description 1
- 150000004043 trisaccharides Chemical class 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 239000011534 wash buffer Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
- 235000008939 whole milk Nutrition 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
- A23C21/00—Whey; Whey preparations
- A23C21/02—Whey; Whey preparations containing, or treated with, microorganisms or enzymes
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
- A23C23/00—Other dairy products
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
- A23C7/00—Other dairy technology
- A23C7/04—Removing unwanted substances other than lactose or milk proteins from milk
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
- A23C9/00—Milk preparations; Milk powder or milk powder preparations
- A23C9/12—Fermented milk preparations; Treatment using microorganisms or enzymes
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L33/00—Modifying nutritive qualities of foods; Dietetic products; Preparation or treatment thereof
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
- C12N15/09—Recombinant DNA-technology
- C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
- C12N15/09—Recombinant DNA-technology
- C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
- C12N15/74—Vectors or expression systems specially adapted for prokaryotic hosts other than E. coli, e.g. Lactobacillus, Micromonospora
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
- C12N15/09—Recombinant DNA-technology
- C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
- C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
- C12N15/80—Vectors or expression systems specially adapted for eukaryotic hosts for fungi
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
- C12N15/09—Recombinant DNA-technology
- C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
- C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
- C12N15/80—Vectors or expression systems specially adapted for eukaryotic hosts for fungi
- C12N15/81—Vectors or expression systems specially adapted for eukaryotic hosts for fungi for yeasts
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N5/00—Undifferentiated human, animal or plant cells, e.g. cell lines; Tissues; Cultivation or maintenance thereof; Culture media therefor
- C12N5/10—Cells modified by introduction of foreign genetic material
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
- C12N9/14—Hydrolases (3)
- C12N9/24—Hydrolases (3) acting on glycosyl compounds (3.2)
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
- C12N9/14—Hydrolases (3)
- C12N9/24—Hydrolases (3) acting on glycosyl compounds (3.2)
- C12N9/2402—Hydrolases (3) acting on glycosyl compounds (3.2) hydrolysing O- and S- glycosyl compounds (3.2.1)
- C12N9/2468—Hydrolases (3) acting on glycosyl compounds (3.2) hydrolysing O- and S- glycosyl compounds (3.2.1) acting on beta-galactose-glycoside bonds, e.g. carrageenases (3.2.1.83; 3.2.1.157); beta-agarase (3.2.1.81)
Definitions
- the present invention relates to lactase, lactase preparations, genes, recombinant vectors and transformants.
- milk Since ancient times, milk has long been used as a nutritious and useful food. Milk contains lactose, a type of sugar. Lactose is degraded in the intestine by lactase, but in some humans, the amount of lactase secreted into the intestine decreases as they grow, so milk and processed milk products (hereinafter collectively referred to as "dairy products”) ) causes so-called lactose intolerance, such as abdominal pain and diarrhea. This has been one of the factors preventing widespread consumption of this nutrient-rich food.
- dairy products with pre-reduced lactose have become available. Such dairy products can be consumed by people who are lactose intolerant without any problem.
- lactose is implemented in various ways. For example, there is a method of treating milk before milk production with a lactase preparation to hydrolyze lactose in the milk (see, for example, Patent Document 1).
- lactose-degrading action stopped as the lactose-degradation progressed in the milk. Therefore, in order to achieve lactose-free milk (lactose concentration of 0.1 mass % or 0.01 mass %), it is necessary to enhance the lactose decomposition activity.
- the present invention has been made in view of the above-mentioned problems, and aims to provide lactase and lactase preparations that have excellent lactose-degrading action in milk (especially in cow's milk).
- the lactase has any one or a combination of the following activities (1) to (6) as the lactase activity.
- the lactase When the lactase is added to milk, the residual lactose concentration reaches 0.1% or less after 24 hours at 10° C.
- the added amount of the lactase protein is 10.1 mg/L or less.
- the residual lactose concentration reaches 0.01% or less after 24 hours at 10° C.
- the added amount of the lactase protein is 15.1 mg/L or less.
- the concentration of residual lactose reaches 0.1% or less after 24 hours at 10°C when adding an amount that gives a final concentration of 1.4 LYU/ml to milk.
- the concentration of residual lactose reaches 0.01% or less after 24 hours at 10°C when adding an amount that gives a final concentration of 2.1 LYU/ml to milk.
- the lactase of the above aspect may be selected from any one of (i) to (iii) below.
- (i) a protein consisting of the amino acid sequence represented by SEQ ID NO: 1; and a protein having lactase activity (iii) a protein consisting of an amino acid sequence having 70% or more identity with the amino acid sequence represented by SEQ ID NO: 1 and having lactase activity May satisfy one or more of the following: (A) The amount of solids contained in milk is 0.1% by mass or more and 30% by mass or less (B) The amount of lactose contained in milk is 0.1% by mass or more and 30% by mass or less (C) Contained in milk Protein content is 0.1% by mass or more and 30% by mass or less (D) Fat content in milk is 0.1% by mass or more and 30% by mass or less
- lactase preparation comprises the lactase described above, At least one selected from water, salts, excipients, suspending agents, buffering agents, stabilizing agents, preservatives and saline.
- the salt may be one or more selected from the group consisting of magnesium chloride, sodium chloride, potassium chloride, calcium chloride and manganese chloride.
- the lactase preparation may contain the lactase described above and a second lactase derived from or having different properties from the lactase.
- Yet another aspect of the present invention is a gene encoding the following protein (i), (ii) or (iii). (i) a protein consisting of the amino acid sequence represented by SEQ ID NO: 1; and a protein having lactase activity (iii) a protein consisting of an amino acid sequence having 70% or more identity with the amino acid sequence represented by SEQ ID NO: 1 and having lactase activity It may consist of any DNA of d).
- (a) DNA consisting of the base sequence shown in SEQ ID NO: 2 (b) a DNA comprising a base sequence in which one to several bases are deleted, substituted or added in the base sequence shown in SEQ ID NO: 2 and encoding the protein having lactase activity; (c) a DNA comprising a nucleotide sequence having a sequence identity of 70% or more to the nucleotide sequence shown in SEQ ID NO: 2 and encoding the protein having lactase activity; (d) a DNA that hybridizes under stringent conditions with a DNA consisting of a nucleotide sequence complementary to the nucleotide sequence shown in SEQ ID NO: 2 and that encodes the protein having lactase activity; SEQ ID NO: 2 is a base sequence containing a termination codon.
- Yet another aspect of the present invention is a recombinant vector having the above gene.
- Yet another aspect of the present invention is a transformant transformed with the above-described recombinant vector.
- Yet another aspect of the present invention is a method for producing lactose-decomposed milk.
- the method for producing the lactose-decomposed milk includes the step of adding the above-described lactase or lactase preparation to raw milk, and a step of reacting the raw material milk with the lactase or the lactase contained in the lactase preparation for a predetermined period of time.
- FIG. 1 is a graph showing changes in residual lactose concentration at 10° C. when BL105A — 1453 and other lactase preparations were added to 1 mL of milk so that the amount of protein was about 15.1 ⁇ g.
- FIG. 2 is a graph in which the horizontal axis (10 to 50 hours) and vertical axis (0 to 0.20% lactose concentration in milk) of FIG. 1 are enlarged.
- FIG. 3 is a graph showing the lactose decomposition rate (reaction rate) when various salts with different concentrations were added to the BL105A_1453 purified enzyme solution.
- FIG. 4 is a graph showing the optimum pH of BL105A_1453 purified enzyme solution.
- FIG. 1 is a graph showing changes in residual lactose concentration at 10° C. when BL105A — 1453 and other lactase preparations were added to 1 mL of milk so that the amount of protein was about 15.1 ⁇ g.
- FIG. 2 is
- FIG. 5 is a graph showing pH stability of BL105A — 1453 purified enzyme solution.
- FIG. 6 is a graph showing the optimum temperature of BL105A_1453 purified enzyme solution.
- FIG. 7 is a graph showing the temperature stability of BL105A — 1453 purified enzyme solution.
- FIG. 8 is a graph showing analysis of the main structure of the product by HPAEC-PAD.
- FIG. 9 is a graph showing changes in lactose concentration during the fermentation stage and storage when each lactase and starter were simultaneously added to milk.
- FIG. 10 is a graph showing changes in lactose concentration when YNL and BL105A_1453 were added singly or in combination to milk.
- the lactase according to the embodiment preferably has any one or a combination of two or more of the following activities (1) to (6) as the lactase activity, and has three or more. is more preferable, it is further preferable to have 4 or more, and it is particularly preferable to have 5 or more. Most preferably, it satisfies all of (1) to (6).
- the amount of the lactase protein added is 15.1 mg/L or less at which the concentration of residual lactose reaches 0.1% after 16 hours at 10°C.
- the amount of the lactase protein added is 30.2 mg/L or less so that the residual lactose concentration reaches 0.01% after 16 hours at 10°C.
- the amount of the lactase protein added is 10.1 mg/L or less so that the residual lactose concentration reaches 0.1% after 24 hours at 10°C.
- the amount of the lactase protein added is 15.1 mg/L or less so that the residual lactose concentration reaches 0.01% after 24 hours at 10°C.
- the concentration of residual lactose after 24 hours at 10°C is 0.01% or less when added to milk at a final concentration of 2.1 LYU/ml.
- the amounts of lactase in (1) to (4) are values calculated by the Bradford method.
- the lactase according to the embodiment is selected from any one of (i) to (iii) below.
- (iii) a protein consisting of an amino acid sequence having 70% or more identity with the amino acid sequence represented by SEQ ID NO: 1 and having lactase activity is a protein having
- lactase activity can be measured by the method described below. Having lactase activity means that when the amount of protein contained in the measurement object is 1 mg, the lactase activity is 1 LYU/mg by the method described later. - refers to those that are more than protein.
- a protein consisting of the amino acid sequence represented by SEQ ID NO: 1 (hereinafter sometimes referred to as BL105A_1453 or 1453) is a lactase derived from Bifidobacterium longum 105-A strain.
- the lactase is a preferred example because it has an extremely high lactose-degrading activity.
- the number of deletions, substitutions, or insertions of amino acid residues in the amino acid sequence represented by SEQ ID NO: 1 in which one to several amino acid residues are deleted, substituted, or inserted is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 8. It is preferable that the number of deletions of amino acid residues in the amino acid sequence represented by SEQ ID NO: 1 exhibit enzyme activity equivalent to that of lactase consisting of the amino acid sequence represented by SEQ ID NO: 1.
- sequence identity with the amino acid sequence represented by SEQ ID NO: 1 is preferably 70% or more, more preferably 80% or more, even more preferably 85% or more, particularly preferably 90% or more, and 95% or more. % or more is particularly preferred, and 99% or more is most preferred.
- sequence identity percentages can be calculated using published or commercially available software whose algorithms compare a reference sequence as a query sequence. For example, BLAST, FASTA, GENETYX (manufactured by Genetics), or the like can be used.
- the lactase it is preferable to use a protein having an amino acid sequence having any of the above sequence identities and having lactase activity.
- a protein consisting of the amino acid sequence represented by SEQ ID NO: 1 exhibits lactase activity in the pH range of 5.0 to 8.5, with an optimum pH range of 5.5 to 6.5.
- the optimum pH is 6.0.
- a protein consisting of the amino acid sequence represented by SEQ ID NO: 1 is a lactase that is stable in the pH range of 5.0 to 9.0.
- a pH of 5.2 to 8.4 is more stable and preferred.
- the protein consisting of the amino acid sequence represented by SEQ ID NO: 1 has lactase activity in the range of over 0°C to 60°C, higher lactase activity in the range of 20°C to 60°C, and an optimum temperature range of 40°C to 40°C. 55°C and the optimum temperature is 50°C.
- a protein consisting of the amino acid sequence represented by SEQ ID NO: 1 is a lactase that exhibits thermostability up to 50°C.
- the protein shows 100% residual lactase activity even after being kept at 50°C for 1 hour.
- the gene according to the embodiment is a gene that encodes the above-described protein having lactase activity, preferably a gene that encodes the amino acid sequence of any one of (i) to (iii) above, more preferably the following (a ) to (d).
- DNA consisting of the base sequence shown in SEQ ID NO: 2 (b) a DNA encoding a protein having lactase activity, consisting of a base sequence in which one to several bases are deleted, substituted or added in the base sequence shown in SEQ ID NO:2; (c) DNA consisting of a nucleotide sequence having 70% or more sequence identity with the nucleotide sequence represented by SEQ ID NO: 2 and encoding a protein having lactase activity (d) a DNA that hybridizes under stringent conditions with a DNA consisting of a nucleotide sequence complementary to the nucleotide sequence shown in SEQ ID NO: 2 and that encodes a protein having lactase activity;
- 1 to several bases are preferably 1 to 10, more preferably 1 to 5.
- base deletion means the absence or disappearance of a base
- base substitution means that a base is replaced with another base
- base addition means that a base is added.
- “Addition” includes addition of bases to one or both ends of a sequence, and insertion of another base between bases in a sequence.
- sequence identity of the base sequences is preferably 70% or more, more preferably 80% or more, even more preferably 85% or more, particularly preferably 90% or more, particularly preferably 95% or more, and 99%. % or more is most preferable.
- Sequence identity of nucleotide sequences can be determined using the algorithm BLAST by Karlin and Altschul (Pro. Natl. Acad. Sci. USA, 1993, 90:5873-5877). Based on this algorithm BLAST, programs called BLASTN and BLASTX have been developed (J.Mol.Biol., 1990, 215, p.403-410). Alternatively, a homology analysis (Search homology) program of genetic information processing software Genetyx may be used. Specific techniques for these analysis methods are known (see www.ncbi.nlm.nih.gov).
- stringent conditions refer to conditions under which nucleotide sequences with high identity hybridize with each other and nucleotide sequences with lower identity do not hybridize with each other. "Stringent conditions" can be appropriately changed depending on the degree of identity desired. The more stringent the conditions, the more identical sequences will hybridize. For example, stringent conditions include conditions described in Molecular Cloning: A Laboratory Manual (Second Edition, J. Sambrook et al., 1989).
- 6 x SSC composition of 1 x SSC: 0.15 M sodium chloride solution, 0.015 M sodium citrate, pH 7.0), 0.5% SDS, 5 x Denhardt and 100 mg / mL solution containing herring sperm DNA and the conditions for hybridization by incubating at 65° C. for 8 to 16 hours together with the probe.
- a protein having lactase activity (lactase) of the present embodiment can be obtained from a transformant obtained by introducing a vector containing the above-described gene encoding lactase into a microorganism according to a known method.
- the transformant may be maintained in the form of a vector, or the gene may be maintained in the genome. That is, when the transformant is cultured in an appropriate medium, the gene encoded on the vector or genome contained in the transformant is expressed, and the protein (lactase) having lactase activity of the present embodiment is produced.
- Lactase can be obtained by isolating and purifying the produced lactase from the culture.
- the gene encoding the lactase of this embodiment can be isolated from Bifidobacterium longum strain 105-A using any method used in the art. For example, after extracting the whole genome DNA of Bifidobacterium longum 105-A strain, the gene is obtained using primers designed based on the gene sequences upstream and downstream of the base sequence of SEQ ID NO: 2. It can be obtained by selectively amplifying the target gene by PCR and purifying the amplified gene.
- the type of vector containing the gene encoding the lactase of this embodiment is not particularly limited, and includes vectors commonly used for protein production, such as plasmids, cosmids, phages, viruses, YACs, and BACs. Among them, plasmid vectors are preferred, and commercially available protein expression plasmid vectors such as pET and pBIC can be preferably used. Procedures for introducing genes into plasmid vectors are well known in the art.
- microorganisms for introducing the constructed vector include Streptomyces, Brevibacillus, Staphylococcus, Enterococcus, Listeria, Bacillus ( Bacillus, Escherichia, Saccharomyces, Shizosaccharomyces, Kluyveromyces, Aspergillus, Penicillium, Trichoderma and eukaryotes microorganisms.
- Bacillus Bacillus, Escherichia, Saccharomyces, Shizosaccharomyces, Kluyveromyces, Aspergillus, Penicillium, Trichoderma and eukaryotes microorganisms.
- a method of introduction a method commonly used in the art can be used.
- the gene introduced into the transformant is expressed to produce the lactase of the present embodiment.
- the medium used for culture can be appropriately selected by those skilled in the art according to the type of transformant.
- the produced lactase of interest can be isolated from the culture by a conventional method and purified by a known purification method.
- Lactase derived from Bifidobacterium longum strain 105-A has a high lactase-degrading action in milk, as shown in the examples below.
- the lactase formulation (lactase composition) of the present embodiment contains, in addition to the active ingredient (lactase), for example, water, salt, excipients, suspending agents, buffers, stabilizers, preservatives, physiological saline, and the like. may contain. Only one type of lactase may be used, or multiple types may be mixed and used. By using a mixture of lactases with different lactose-degrading actions for subjects containing lactose, it becomes easier to enjoy the benefits of each lactase.
- the initial lactose decomposition rate is fast, but the final lactose decomposition rate is 99%.
- a lactase that does not reach up to 9% and a lactase that does not have a high initial decomposition rate of lactose but has a final decomposition rate of 99.9% or more of lactose are used in combination.
- a first lactase and a second lactase derived from or having different properties from the first lactase can be combined according to desired properties and used as a lactase preparation. There is no limit to the number of third lactase, fourth lactase, etc. to be mixed.
- this lactase originates from Bifidobacterium longum 105-A, and the final lactose decomposition rate reaches 99.9% or more.
- a lactase having a different origin or a lactase having a high initial decomposition rate such as milk can be used as the second lactase.
- yeast-derived lactase, mold-derived lactase, and lactic acid lactase-derived lactase can be used. More specifically, lactase derived from Kluyveromyces lactis and Kluyveromyces marxianus, lactase derived from Aspergillus oryzae, and lactase derived from Lactobacillus delbrueckii.
- the mass of the lactase protein may be used as a reference.
- the mass ratio may be in the range of 1:99 to 99:1, preferably in the range of 10:90 to 90:10, and 20:80. It is more preferably in the range of ⁇ 80:20 and most preferably in the range of 25:75 to 50:50. These ranges make it easier to provide a lactase preparation having multiple properties.
- the lactase preparation of this embodiment improves the lactase activity by having a salt or its ion.
- Such salts include magnesium chloride, sodium chloride, potassium chloride, calcium chloride, manganese chloride and the like.
- Examples of ions include monovalent cations such as sodium and potassium and divalent cations such as magnesium, manganese and calcium.
- the lactase preparation of the present embodiment has two or more salts or ions thereof selected from the group consisting of magnesium chloride, sodium chloride, potassium chloride, calcium chloride, and manganese chloride, thereby significantly improving lactase activity.
- a lactase preparation containing a salt or its ion may be used as long as it promotes the decomposition of lactose, and may be added to or contained in an aqueous solution of lactose in addition to raw milk such as cow's milk. Even if the lactase formulation does not contain the above-described salts or ions thereof, the lactose decomposition rate in the reaction system can be increased if the above-described salts or ions thereof are included in the reaction system. For example, the lactose decomposition rate can be accelerated by further adding the above-described salt to the reaction system in which the active ingredient (lactase) is added to an aqueous lactose solution to contain the salt as ions.
- the lower limit of the salt content in the lactase formulation is preferably 0.1 mM or more, more preferably 0.5 mM or more, may be 1 mM or more, or may be 10 mM or more. Well, 40 mM or more is more preferable.
- the upper limit of the salt content is preferably 1000M or less, more preferably 500M or less, may be 100M or less, and more preferably 50M or less.
- the upper limit and lower limit of the content of the salt contained in the lactase formulation can be appropriately combined from the above ranges.
- the lower limit of the monovalent cation contained in the lactase preparation is preferably 0.1 mM or more, more preferably 1 mM or more, may be 10 mM or more, may be 100 mM or more, and is more preferably 500 mM or more.
- the upper limit of the monovalent cation is preferably 1000M or less, more preferably 500M or less, may be 100M or less, and more preferably 50M or less.
- the upper and lower limits of the monovalent cation contained in the lactase formulation can be appropriately combined from the above ranges.
- the lower limit of the divalent cation contained in the lactase preparation is preferably 0.1 mM or higher, more preferably 1 mM or higher, may be 10 mM or higher, and is further preferably 40 mM or higher.
- the upper limit of the divalent cation is preferably 100M or less, more preferably 20M or less, may be 10M or less, and more preferably 2M or less.
- the upper and lower limits of the divalent cations contained in the lactase formulation can be appropriately combined from the above ranges.
- the pH of the aqueous lactose solution is typically 4.5 to 9.0 from the viewpoint of obtaining a sufficient rate of lactose decomposition by salt.
- the shape of the lactase preparation is not limited. It may be solid or liquid at room temperature. It is preferred that the lactase formulation be in solid form when used in solids, and in liquid form when used in liquids (eg, milk).
- the lower limit of the protein content in the lactase preparation of the present embodiment is preferably 0.072 mg/mL or more for a liquid lactase preparation, and 0.72 mg/mL for a solid lactase preparation. g or more is preferable.
- the upper limit of the protein content is not particularly limited, it is preferably 720 mg/mL or less, for example. When the content of the protein is equal to or higher than the lower limit, desired activity can be ensured even if the storage time is prolonged.
- the amount of protein contained in the lactase preparation of this embodiment can be measured by the Bradford method.
- the lactase preparation of the present embodiment preferably has a lactase activity of 10 to 100,000 LYU/mL, more preferably 100 to 90,000 LYU/mL, and 1,000 to 80,000 LYU/mL. It is even more desirable to have activity.
- the activity measurement method is as follows. A lactose preparation (enzyme solution) to be measured was added to a lactose solution (final concentration of 10%) dissolved in 0.1 M phosphate buffer (pH 6.5) containing 0.1 mM manganese chloride solution, and the pH was 6.5 and 37. °C for 10 minutes. The reaction is terminated by the addition of 1.5N sodium hydroxide solution.
- Glucose CII Test Wako manufactured by Wako Pure Chemical Industries
- the amount of enzyme that produces 1 ⁇ mol of glucose per minute under these conditions is defined as 1 LYU.
- the stabilizer content is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass.
- stabilizers include sorbitol and glycerin.
- Milk for which the lactase or lactase preparation of the present embodiment is used is not particularly limited as long as it contains lactose.
- Milk is derived from, for example, cows, goats, sheep, and the like. Among these, it is preferable to use bovine milk. These milks may be used as they are, and water, whole milk powder, skimmed milk powder, cream powder, whey powder, protein-concentrated whey powder, buttermilk powder, sweetened milk powder, prepared milk powder, etc. may be added as necessary. It is also possible to adjust the solid content, the amount of lactose, etc., which will be described later.
- the above-mentioned milk to which substances other than enzymes have been added is referred to as raw material milk.
- the amount of solids contained in the raw milk is 0.1% by mass or more and 30% by mass or less, 0.5% by mass or more and 20% by mass or less, 1% by mass or more and 10% by mass or less, 2% by mass or more and 8% by mass or less. 4.0% by mass or more is preferable, 6.0% by mass or more is more preferable, and 8.0% by mass or more is even more preferable.
- the upper limit of the solid content contained in the raw material milk is not particularly limited, it is, for example, 30% by mass.
- the amount of lactose contained in the raw milk is 0.1% by mass or more and 30% by mass or less, 0.5% by mass or more and 20% by mass or less, 1% by mass or more and 10% by mass or less, 2% by mass or more and 8% by mass or less. 4.0% by mass or more and 5.8% by mass or less is preferable, 4.4% by mass or more and 5.4% by mass or less is preferable, and 4.8% by mass or more and 5.0% by mass or less is more preferable.
- the amount of protein contained in the raw milk is 0.1% by mass or more and 30% by mass or less, 0.5% by mass or more and 20% by mass or less, 1% by mass or more and 10% by mass or less, 2% by mass or more and 8% by mass or less. 2.0% by mass or more and 4.8% by mass or less is preferable, 2.6% by mass or more and 4.2% by mass or less is more preferable, and 3.2% by mass or more and 3.6% by mass or less is even more preferable. .
- the amount of fat contained in the raw milk is 0.1% by mass or more and 30% by mass or less, 0.5% by mass or more and 20% by mass or less, 1% by mass or more and 10% by mass or less, 2% by mass or more and 8% by mass or less. 1.5% by mass or more is preferable, 2.5% by mass or more is more preferable, and 3.5% by mass or more is even more preferable.
- the sterilization method of the raw milk is not particularly limited, but low temperature sterilization (LTLT), high temperature sterilization (HTLT), and ultra high temperature flash sterilization (UHT) are listed in order of low heat history.
- LTLT low temperature sterilization
- HTLT high temperature sterilization
- UHT ultra high temperature flash sterilization
- Raw milk may be unpasteurized raw milk.
- the mixture After adding the lactase or lactase preparation of the present embodiment to the raw material milk described above at a predetermined concentration, the mixture is reacted at a predetermined temperature for a predetermined time to produce lactose-decomposed milk having a high lactose decomposition rate. It is preferable to use cow's milk as raw material milk.
- the reaction time is, for example, 1 hour to 48 hours, preferably 12 hours to 24 hours.
- the reaction temperature is, for example, above 0°C to 40°C, preferably 1°C to 25°C, 1°C to 10°C.
- the lactose concentration contained in milk is about 4.7% by mass.
- lactose contained in lactose-decomposed milk is preferably 0.1% by mass or less (lactose decomposition rate of 97.87% or more), more preferably 0.01% by mass or less (lactose decomposition rate of 99.79% or more). This allows it to be marketed as lactose-free milk. If the lactase in raw material milk is 1.4 LYU/mL or more, lactose-decomposed milk having a lactose content of 0.1% by mass or less (lactose decomposition rate of 97.87% or more) can be easily obtained, which is preferable.
- lactase in raw material milk is 2.1 LYU/mL or more
- lactose-decomposed milk having a lactose content of 0.01% by mass or less lactose decomposition rate of 99.79% or more
- BL105A_1453 [derived from Bifidobacterium longum 105-A strain, E. coli recombinant expressed and purified enzyme]
- YNL 2 [derived from Kluyveromyces lactis, Godo Shusei Co., Ltd., #21006]
- YNL 2LS [derived from Kluyveromyces lactis, Godo Shusei Co., Ltd., #21002]
- Lactase A [derived from Kluyveromyces lactis]
- Lactase B [derived from Bifidobacterium bifidum]
- Lactase C [derived from Lactobacillus delbrueckii ssp. bulgaricus]
- BL105A_1453 crude enzyme solution E. coli into which the BL105A_1453 expression plasmid pET23a-BL105A_1453 was introduced.
- E. coli BL21(DE3) transformant was inoculated into a test tube containing 5 mL of LB Amp medium (50 ⁇ g/mL) and cultured at 18° C. overnight. 250 ⁇ L of the culture solution was inoculated into a 100 mL Erlenmeyer flask containing 25 mL of TB Amp medium (50 ⁇ g/mL) and cultured with shaking at 18°C. This was done for 10 pieces.
- IPTG isopropyl- ⁇ -thiogalactopyranoside
- a final concentration of 0.5 mM when the absorbance A 610 reached 0.5, and production of the recombinant protein was initiated. induced. Induction culture was carried out at 18°C for 24 hours. Cells were recovered from the culture medium by centrifugation (8,000 rpm, 10 minutes, 4° C.) and suspended in 10 mL of binding buffer for Ni column chromatography (20 mM sodium phosphate buffer, pH 7.5, 500 mM sodium chloride). , and sonication (URTRA SONIC DISRUPTOR UR-200P, Tomy Seiko Co., Ltd.) to disrupt the cells. The supernatant obtained by centrifugation (8,000 rpm, 10 minutes, 4° C.) was used as a crude enzyme solution containing BL105A_1453.
- ⁇ Production of BL105A_1453 purified enzyme solution The crude enzyme solution obtained above was applied to a Ni-NTA Agarose column ( ⁇ 1.0 cm ⁇ 4.0 cm; QIAGEN) equilibrated with a binding buffer. After removing non-adsorbed proteins with a washing buffer (20 mM sodium phosphate buffer, pH 7.5, 500 mM sodium chloride, 50 mM imidazole), the adsorbed proteins were eluted with a 20-500 mM imidazole linear gradient (elution buffer A, 20 mM Sodium phosphate buffer, pH 7.5, 20 mM imidazole; Elution buffer B, 20 mM sodium phosphate buffer, pH 7.5, 500 mM imidazole; 60 mL each).
- a washing buffer (20 mM sodium phosphate buffer, pH 7.5, 500 mM sodium chloride, 50 mM imidazole
- Elution buffer B 20 mM sodium phosphate buffer, pH 7.5, 500
- the fraction volume was 8 mL for washing and 3 mL for elution.
- the collected fraction was dialysed with a dialysis membrane (cellulose tube 36/32; Viskase Companies, Inc.) once per 1 L of 10 mM sodium phosphate buffer (pH 6.5) and twice per 5 L of the same buffer. dialyzed twice. After dialysis, it was concentrated to 1.5 mL using Amicon Ultra-15 (MWCO, 100,000; Merck Millipore). This was used as BL105A_1453 purified enzyme solution. Glycerol was added to the resulting purified enzyme solution to a final concentration of 50% and stored at -80°C. The purified enzyme solution was subjected to SDS-PAGE and confirmed to be a single band.
- a blank was prepared by adding 20 ⁇ L of buffer solution to 1 mL of milk.
- BL105A_1453 a product (built-in) activity of 3500 LYU/mL was assumed. The reaction was stopped by adding 1/20 amount of 20% sulfosalicylic acid.
- a 0.1 M phosphate buffer (pH 6.5) containing 0.1 mM manganese chloride was used as the buffer.
- HPLC analysis>> A sample diluted 5-fold with ultrapure water was filtered through a filter with a pore size of 0.22 ⁇ m, and the filtrate was analyzed using HPLC.
- the conditions for HPLC analysis are as follows.
- the conditions for HPAEC-PAD analysis are as follows. Body: Dionex, ICS-6000 + , AS-Ap Autosampler Column: Dionex, CarboPac PA1 ( ⁇ 4.0 mm ⁇ 250 mm), 20 ° C.
- lactose decomposition rate was calculated by comparing the residual lactose concentration of each sample with the lactose concentration of milk analyzed under the same conditions.
- Figures 1 and 2 show changes in residual lactose concentration at 10°C when BL105A_1453 and other lactase proteins were added in an amount of about 15.1 ⁇ g to 1 mL of milk.
- Condition 2 Mixed salts (NaCl, KCl, MgCl 2 ) containing 139 mM lactose (Na + : 18.4 mM, K + : 39.6 mM, Mg 2+ : 4.25 mM)
- Condition 3 Milk Condition 4: Fractionated milk Condition 5: Desalted fractionated milk-1 (Electrodialysis removes charged components with a molecular weight ⁇ 100 in Condition 4)
- Condition 6 Desalted fractionated milk-2 (remove the charged component of 4 with an ion exchange resin) The lactose decomposition rate was calculated by the following procedure.
- Glucose concentration was calculated from A 505 based on a calibration curve (0-600 ⁇ M glucose and A 505 ).
- One unit was defined as the amount of enzyme that hydrolyzes 1 ⁇ mol of lactose per minute under these conditions. The results obtained are shown in Tables 3 and 4.
- Electrodialysis of fractionated milk reduced the activity of YNL 2 to a level of approximately 139 mM lactose, and addition of mixed salts increased the activity to a level exceeding the level in milk, suggesting that the salt in the milk inhibited the activity of the enzyme. considered to have made a significant contribution to The activity of BL105A_1453 decreased to the level of 139 mM lactose when fractionated milk was desalted with an ion-exchange resin, but the activity decreased moderately when desalted by electrodialysis. Since the addition of mixed salts results in the level of activity in milk, it is thought that the salt in the milk acts on the activation, but it is also possible that components that cannot be removed by electrodialysis act as a substitute for salt.
- Reaction system 1 (Na + ) (50 ⁇ L) 2 mM ONPG, 10 mM MES-NaOH (pH 6.0, containing 5.3 mM Na + ), 0-50 mM NaCl
- enzyme reaction system 2 (K + , Mg 2+ , Mn 2+ , Ca 2+ ) (50 ⁇ L) 2 mM ONPG, 10 mM MES-NaOH (pH 6.0, containing 6 mM K + ), 0-50 mM KCl, 0-10 mM MgCl 2 , 0-0.1 mM MnCl 2 or 0-50 mM CaCl 2
- the enzyme ONPG degradation rate is It was calculated according to the following procedure.
- substrate 100 mg of ONPG/100 mL of distilled water
- the lactase activity value was calculated from the absorbance of OD 420 of the reaction solution.
- One unit of lactase activity was defined as the amount of enzyme required to change the measured value by 1 in 10 minutes. The results obtained are shown in FIG.
- the optimum pH of BL105A_1453 was 6.0.
- the pH stability of lactase was measured by the following method.
- the BL105A_1453 enzyme solution was diluted 10-fold with each buffer (pH 3.0-10.5) and incubated at 37° C. for 30 minutes. After cooling on ice for 3 minutes, it was further diluted 200-fold with pH 6.0 buffer. 300 ⁇ L of the diluted enzyme solution was placed in a 1.5 mL tube, mixed with 300 ⁇ L of buffer solution, and pre-incubated at 37°C for 3 minutes. It was reacted with 600 ⁇ L of substrate (100 mg of ONPG/100 mL of distilled water) at 37° C. for 1 minute, and 1200 ⁇ L of 0.2 M sodium carbonate was added to terminate the reaction.
- the lactase activity value was calculated from the absorbance of OD 420 of the reaction solution.
- One unit of lactase activity was defined as the amount of enzyme required to change the measured value by 1 in 10 minutes.
- the pH stability of lactase can be measured by the same method as shown for the optimum pH of lactase, except that the buffer solution used is incubated at 37° C. for 30 minutes. The following buffer solutions were used at each pH, and the pH was plotted with the measured values when the enzyme was diluted.
- ⁇ Optimum Temperature>> The optimum temperature of lactase was measured by the following method. Take 300 ⁇ L of BL105A_1453 enzyme solution diluted 2000 times with pH 6.0 sodium phosphate buffer, mix with 300 ⁇ L of buffer, Pre-incubated at 50, 55, 60°C for 3 minutes. After that, the activity was measured at each temperature in the same manner as the pH stability test. The results obtained are shown in FIG. In FIG. 6, the activity at 37° C. was used as the reference (relative activity 100%). The optimum temperature for BL105A_1453 was 50°C.
- the BL105A_1453 enzyme solution was diluted 10-fold with pH 6.0 buffer and incubated at 37, 50, 55, 60, 65 and 70°C for 0, 5, 10, 30 and 60 minutes. After cooling on ice for 3 minutes, it was further diluted 200-fold with pH 6.0 buffer. 300 ⁇ L of the diluted enzyme solution was placed in a test tube, mixed with 300 ⁇ L of buffer solution, and pre-incubated at 37° C. for 3 minutes. After that, the activity was measured in the same manner as the pH stability test. The results obtained are shown in FIG. BL105A_1453 showed 100% residual lactase activity even after reacting at 50°C for 1 hour.
- the theoretical yield of galacto-oligosaccharides at this time is about 74% by mass.
- three molecules of lactose yield two molecules of glucose and one molecule of a tetrasaccharide galactooligosaccharide.
- the theoretical yield of galacto-oligosaccharides at this time is about 65% by mass. Therefore, when galacto-oligosaccharides are produced from lactose, it is most efficient in terms of yield to produce only trisaccharide galacto-oligosaccharides.
- the galacto-oligosaccharide yield (% by mass) means the percentage obtained by dividing the "production amount of galacto-oligosaccharide” by the “consumption amount of lactose".
- Galacto-oligosaccharides produced can be measured by HPLC. Specifically, the method described in WO2019/194062 may be adopted.
- a starter (lactic acid bacteria YF-L812 strain 10 mg/100 g, Bifidobacterium BB-12 strain 5 mg/100 g) is added to commercially available milk (manufactured by Meiji Co., Ltd.), stirred, and after dispensing, the BL105A_1453 enzyme solution is adjusted to 0 with a product activity of 5200 LYU/mL. .02 and 0.06%.
- a group with 0.02% YNL 2 addition and a group with 0.02% lactase B (enzyme derived from Bifidobacterium bifidum) were provided.
- FIG. 9 shows changes in lactose concentration in the fermented milk obtained as described above.
- BL105A_1453 had a decomposition rate equivalent to lactase B at the end of fermentation (4 hours later), and the lactose concentration in the sample was 0.4%.
- 0.06% BL105A_1453 was added, the lactose concentration reached 0.1% or less after 2 hours of fermentation. Only lactase B reacted even under conditions of 10° C. and low pH after completion of fermentation, and the lactose concentration reached 0.1% or less 48 hours after the start of fermentation.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Genetics & Genomics (AREA)
- Chemical & Material Sciences (AREA)
- Zoology (AREA)
- Organic Chemistry (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Wood Science & Technology (AREA)
- Biomedical Technology (AREA)
- Biotechnology (AREA)
- General Engineering & Computer Science (AREA)
- Microbiology (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Molecular Biology (AREA)
- Polymers & Plastics (AREA)
- Food Science & Technology (AREA)
- Mycology (AREA)
- Physics & Mathematics (AREA)
- Biophysics (AREA)
- Plant Pathology (AREA)
- Medicinal Chemistry (AREA)
- Cell Biology (AREA)
- Nutrition Science (AREA)
- Dairy Products (AREA)
- Enzymes And Modification Thereof (AREA)
Abstract
Description
(1)牛乳に前記ラクターゼを添加したとき、10℃、16時間後における残存乳糖濃度が0.1%以下に達する前記ラクターゼのタンパク質の添加量が15.1mg/L以下である。
(2)牛乳に前記ラクターゼを添加したとき、10℃、16時間後における残存乳糖濃度が0.01%以下に達する前記ラクターゼのタンパク質の添加量が30.2mg/L以下である。
(3)牛乳に前記ラクターゼを添加したとき、10℃、24時間後における残存乳糖濃度が0.1%以下に達する前記ラクターゼのタンパク質の添加量が10.1mg/L以下である。
(4)牛乳に前記ラクターゼを添加したとき、10℃、24時間後における残存乳糖濃度が0.01%以下に達する前記ラクターゼのタンパク質の添加量が15.1mg/L以下である。
(5)牛乳に対して、終濃度1.4LYU/mlとなる量を添加したときの、10℃、24時間後における残存乳糖濃度が0.1%以下に達する。
(6)牛乳に対して、終濃度2.1LYU/mlとなる量を添加したときの、10℃、24時間後における残存乳糖濃度が0.01%以下に達する。
上記態様のラクターゼにおいて、以下の(i)~(iii)のいずれか一つから選択されてもよい。
(i)配列番号1で表されるアミノ酸配列からなるタンパク質
(ii)配列番号1で表されるアミノ酸配列の1~数個のアミノ酸残基が欠失、置換または挿入されたアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
(iii)配列番号1で表されるアミノ酸配列の70%以上の同一性を有するアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
また、上記態様のラクターゼにおいて、上述の牛乳が下記の一つ以上を充足してもよい。
(A)牛乳中に含まれる固形分量は0.1質量%以上30質量%以下
(B)牛乳中に含まれる乳糖量は0.1質量%以上30質量%以下
(C)牛乳中に含まれるタンパク量は0.1質量%以上30質量%以下
(D)牛乳中に含まれる脂肪分量は0.1質量%以上30質量%以下
水、塩、賦形剤、懸濁剤、緩衝剤、安定化剤、保存剤および生理食塩水から選択される少なくとも一つと、を含有する。前記塩が塩化マグネシウム、塩化ナトリウム、塩化カリウム、塩化カルシウム及び塩化マンガンからなる群より選ばれる1種以上であってもよい。また、当該ラクターゼ製剤は、上述したラクターゼと、当該ラクターゼと由来または性質の異なる第二のラクターゼと、を含有してもよい。
(i)配列番号1で表されるアミノ酸配列からなるタンパク質
(ii)配列番号1で表されるアミノ酸配列の1~数個のアミノ酸残基が欠失、置換または挿入されたアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
(iii)配列番号1で表されるアミノ酸配列の70%以上の同一性を有するアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
上記態様の遺伝子は、下記(a)~(d)のいずれかのDNAからなっていてもよい。
(a)配列番号2で示される塩基配列からなるDNA
(b)配列番号2で示される塩基配列において1~数個の塩基が欠失、置換または付加された塩基配列からなり、かつラクターゼ活性を有する前記タンパク質をコードするDNA
(c)配列番号2で示される塩基配列に対して70%以上の配列同一性を有する塩基配列からなり、かつラクターゼ活性を有する前記タンパク質をコードするDNA
(d)配列番号2で示される塩基配列に相補的な塩基配列からなるDNAとストリンジェントな条件下でハイブリダイズし、かつラクターゼ活性を有する前記タンパク質をコードするDNA
なお、配列番号2は終止コドンを含んだ塩基配列である。
前記原料乳に、前記ラクターゼまたは前記ラクターゼ製剤に含まれるラクターゼを所定の時間だけ反応させる工程と、を備える。
実施形態に係るラクターゼは、ラクターゼ活性として、以下の(1)~(6)に記載の活性のうち、いずれか1つ、または複数の組み合わせを2つ以上有することが好ましく、3つ以上有することがより好ましく、4つ以上有することがさらに好ましく、5つ以上有することが特に好ましい。(1)~(6)を全て充足するものであることが最も好ましい。
(1)牛乳に前記ラクターゼを添加したとき、10℃、16時間後における残存乳糖濃度が0.1%に達する前記ラクターゼのタンパク質の添加量が15.1mg/L以下である。
(2)牛乳に前記ラクターゼを添加したとき、10℃、16時間後における残存乳糖濃度が0.01%に達する前記ラクターゼのタンパク質の添加量が30.2mg/L以下である。
(3)牛乳に前記ラクターゼを添加したとき、10℃、24時間後における残存乳糖濃度が0.1%に達する前記ラクターゼのタンパク質の添加量が10.1mg/L以下である。
(4)牛乳に前記ラクターゼを添加したとき、10℃、24時間後における残存乳糖濃度が0.01%に達する前記ラクターゼのタンパク質の添加量が15.1mg/L以下である。
(5)牛乳に対して、終濃度1.4LYU/mlとなる量を添加したときの、10℃、24時間後における残存乳糖濃度が0.1%以下である。
(6)牛乳に対して、終濃度2.1LYU/mlとなる量を添加したときの、10℃、24時間後における残存乳糖濃度が0.01%以下である。
なお、(1)から(4)のラクターゼ量は、Bradford法により算出される値である。
(i)配列番号1で表されるアミノ酸配列からなるタンパク質
(ii)配列番号1で表されるアミノ酸配列の1~数個のアミノ酸残基が欠失、置換または挿入されたアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
(iii)配列番号1で表されるアミノ酸配列の70%以上の同一性を有するアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
上記(i)は、後述するようにラクターゼ活性を有するタンパク質である。
本実施形態に係るラクターゼは、上記いずれかの配列同一性を有するアミノ酸配列からなり、ラクターゼ活性を有するタンパク質を使用することが好ましい。
配列番号1で表されるアミノ酸配列からなるタンパク質は、pH5.0~8.5の範囲でラクターゼ活性を示し、至適pH範囲は5.5~6.5である。至適pHは6.0である。
配列番号1で表されるアミノ酸配列からなるタンパク質は、pH5.0~9.0の範囲で安定であるラクターゼである。pH5.2~8.4がより安定であり好ましい。
配列番号1で表されるアミノ酸配列からなるタンパク質は、0℃超~60℃の範囲でラクターゼ活性があり、20℃~60℃の範囲でよりラクターゼ活性が高く、至適温度範囲は40℃~55℃であり、至適温度は50℃である。
配列番号1で表されるアミノ酸配列からなるタンパク質は、50℃まで熱安定性を示すラクターゼである。当該タンパク質を50℃にて1時間保持後も100%のラクターゼ残存活性を示す。
実施形態に係る遺伝子は、ラクターゼ活性を有する上述のタンパク質をコードする遺伝子であり、好ましくは上記(i)~(iii)のいずれかのアミノ酸配列をコードする遺伝子であり、より好ましくは下記(a)~(d)のいずれかのDNAからなる遺伝子である。
(a)配列番号2で示される塩基配列からなるDNA
(b)配列番号2で示される塩基配列において1~数個の塩基が欠失、置換または付加された塩基配列からなり、かつラクターゼ活性を有するタンパク質をコードするDNA
(c)配列番号2で示される塩基配列に対して70%以上の配列同一性を有する塩基配列からなり、かつラクターゼ活性を有するタンパク質をコードするDNA
(d)配列番号2で示される塩基配列に相補的な塩基配列からなるDNAとストリンジェントな条件下でハイブリダイズし、かつラクターゼ活性を有するタンパク質をコードするDNA
塩基配列の配列同一性は、Karlin and AltschulによるアルゴリズムBLAST(Pro.Natl.Acad.Sci.USA,1993,90:5873-5877)を用いて決定することができる。このアルゴリズムBLASTに基づいて、BLASTNやBLASTXとよばれるプログラムが開発されている(J.Mol.Biol.,1990,215,p.403-410)。また、遺伝情報処理ソフトウェアGenetyxのホモロジー解析(Search homology)プログラムを用いてもよい。これらの解析方法の具体的な手法は公知である(www.ncbi.nlm.nih.gov参照)。
本実施形態のラクターゼ製剤(ラクターゼ組成物)は、有効成分(ラクターゼ)の他、例えば、水、塩、賦形剤、懸濁剤、緩衝剤、安定化剤、保存剤、生理食塩水等を含有してもよい。
ラクターゼは1種類だけ使用してもよいし、複数種類を混合して使用してもよい。乳糖を含む対象に対し、乳糖分解作用の異なるラクターゼを混合して使用することで、それぞれのラクターゼが有するメリットを享受しやすくなる。例えば、由来の異なるラクターゼを複数組み合わせる場合、中性領域で乳糖分解作用を有するラクターゼと酸性領域で乳糖分解作用を有するラクターゼを併用する場合、乳糖の初期分解速度が早いが乳糖最終分解率が99.9%までには達しないラクターゼと乳糖の初期分解速度は早くないが乳糖最終分解率が99.9%以上のラクターゼを併用する場合等である。
第一のラクターゼと前記第一のラクターゼと由来または性質の異なる第二のラクターゼを所望の特性に応じて組み合わせ、ラクターゼ製剤として使用することができる。第三のラクターゼ、第四のラクターゼ等、混合する数に制限は無い。第一のラクターゼとしてBL105A_1453を使用する場合、このラクターゼの由来はBifidobacterium longum 105-Aであり、乳糖最終分解率が99.9%以上に達する。この酵素に、由来が異なるラクターゼや、乳等の初期分解速度の速いラクターゼを第二のラクターゼとして使用することができる。例えば、酵母由来のラクターゼやカビ由来のラクターゼ、乳酸菌由来のラクターゼを使用することができる。より具体的には、Kluyveromyces lactisやKluyveromyces marxianus由来のラクターゼ、Aspergillus oryzae由来のラクターゼ、Lactobacillus delbrueckii由来のラクターゼである。
ラクターゼ製剤中に複数のラクターゼを含有させる場合、ラクターゼタンパクの質量を基準にすればよい。第一のラクターゼと第二のラクターゼを含有させる場合、質量比は、1:99~99:1の範囲にすればよく、10:90~90:10の範囲にすることが好ましく、20:80~80:20の範囲にすることがより好ましく、25:75~50:50の範囲にすることが最も好ましい。これらの範囲にすることによって、複数の特性を兼ね備えたラクターゼ製剤を提供しやすくなる。
乳糖分解速度を早める観点から、ラクターゼ製剤に含まれる塩の含有量の下限は、0.1mM以上が好ましく、0.5mM以上がより好ましく、1mM以上であってもよく、10mM以上であってもよく、40mM以上がさらに好ましい。
塩の含有量の上限は、1000M以下が好ましく、500M以下がより好ましく、100M以下であっても良く、50M以下がさらに好ましい。ラクターゼ製剤に含まれる塩の含有量の上限値及び下限値は、上記の範囲を適宜組み合わせることができる。
ラクターゼ製剤に含まれる一価の陽イオンの下限は、0.1mM以上が好ましく、1mM以上がより好ましく、10mM以上であっても良く、100mM以上であってもよく、500 mM以上がさらに好ましい。一価の陽イオンの上限は、1000M以下が好ましく、500M以下がより好ましく、100M以下であってもよく、50M以下がさらに好ましい。ラクターゼ製剤に含まれる一価の陽イオンの上限値及び下限値は、上記の範囲を適宜組み合わせることができる。
ラクターゼ製剤に含まれる二価の陽イオンの下限は、0.1mM以上が好ましく、1mM以上がより好ましく、10mM以上であってもよく、40mM以上がさらに好ましい。二価の陽イオンの上限は、100M以下が好ましく、20M以下がより好ましく、10M以下であっても良く、2M以下がさらに好ましい。ラクターゼ製剤に含まれる二価の陽イオンの上限値及び下限値は、上記の範囲を適宜組み合わせることができる。
塩による乳糖分解速度を十分に得る観点から、ラクトース水溶液のpHは、典型的には、4.5~9.0である。
本実施形態のラクターゼ製剤に含まれるタンパク質の含有量の下限値は、液体状のラクターゼ製剤であれば0.072mg/mL以上であることが好ましく、固体状のラクターゼ製剤であれば0.72mg/g以上であることが好ましい。一方、当該タンパク質の含有量の上限値は特に制限されないが、たとえば、720mg/mL以下であることが好ましい。
当該タンパク質の含有量が下限値以上であることにより、保存時間が長期化しても、所望の活性を確保することができる。
本実施形態のラクターゼ製剤に含まれるタンパク質量は、Bradford法で測定することができる。
本実施形態のラクターゼ製剤は、10~100,000LYU/mLのラクターゼ活性を有することが望ましく、100~90,000LYU/mLの活性を有することがより望ましく、1,000~80,000LYU/mLの活性を有することがさらに望ましい。
活性の測定方法は、以下のとおりである。0.1mM塩化マンガン溶液を含む0.1Mリン酸緩衝液(pH6.5)に溶解した乳糖溶液(終濃度10%)に測定対象のラクターゼ製剤(酵素液)を添加し、pH6.5、37℃で、10分間保持する。反応を、1.5Nの水酸化ナトリウム溶液の添加によって終了させる。反応液を常温まで冷まし、1.5Nの塩酸を添加することにより溶液を中和する。反応液中の遊離グルコース量の定量に、グルコースCIIテストワコー(和光純薬工業製)を用いる。本条件下で1分間に1μmolのグルコースを生成する酵素量を1LYUと定義する。
本実施形態のラクターゼ製剤は、安定化剤の含有量が10~90質量%であることが好ましく、20~80質量%であることがより好ましく、30~70質量%であることがさらに好ましい。
安定化剤としては、ソルビトールやグリセリン等が挙げられる。
(原料乳)
本実施形態のラクターゼまたはラクターゼ製剤が使用される乳は、乳糖を含んでいるものであれば特に制限はない。乳の由来としては、例えば、ウシ、ヤギ、ヒツジ等がある。これらの中でもウシ由来の乳を使用することが好ましい。
これらの乳をそのまま使用してもよく、必要に応じて水、全粉乳、脱脂粉乳、クリームパウダー、ホエイパウダー、たんぱく質濃縮ホエイパウダー、バターミルクパウダー、加糖粉乳、調製粉乳等を加えてもよい。後述する固形分量、乳糖量等を調整することも可能である。本実施形態においては、上記の乳に酵素以外のものを添加したものを原料乳という。
反応時間としては、例えば、1時間~48時間であり、好ましくは12時間~24時間である。
反応温度は、例えば、0℃超~40℃であり、好ましくは1℃~25℃、1℃~10℃である。
牛乳中に含まれる乳糖濃度は約4.7質量%である。乳糖分解乳に含まれる乳糖量は、0.1質量%以下(乳糖分解率97.87%以上)が好ましく、0.01質量%以下(乳糖分解率99.79%以上)がより好ましい。これによって、ラクトースフリーミルクとして売ることが可能となる。
原料乳中のラクターゼが1.4LYU/mL以上であれば、乳糖量が0.1質量%以下(乳糖分解率97.87%以上)の乳糖分解乳を得やすくなるため好ましい。
原料乳中のラクターゼが2.1LYU/mL以上であれば、乳糖量が0.01質量%以下(乳糖分解率99.79%以上)の乳糖分解乳を得やすくなるため好ましい。
評価に用いたラクターゼを以下に示す。
BL105A_1453:〔Bifidobacterium longum 105-A株由来、E.coli組換え発現精製酵素〕
YNL 2:〔Kluyveromyces lactis由来、合同酒精株式会社製剤、#21006〕
YNL 2LS:〔Kluyveromyces lactis由来、合同酒精株式会社製剤、#21002〕
ラクターゼA:〔Kluyveromyces lactis由来〕
ラクターゼB:〔Bifidobacterium bifidum由来〕
ラクターゼC:〔 Lactobacillus delbrueckii ssp. bulgaricus由来〕
BL105A_1453の発現プラスミドpET23a-BL105A_1453を導入したE.coli BL21(DE3)形質転換体を5mLのLB Amp培地(50μg/mL)を含む試験管に植菌して18℃で一晩培養した。培養液250μLを25mLのTB Amp培地(50μg/mL)を含む100mL容三角フラスコに接種し、18℃にて振盪培養した。これを10本分行った。吸光光度計を用いて、吸光度A610が0.5に達した時点で終濃度0.5mMとなるようにIPTG(イソプロピル-β-チオガラクトピラノシド)を添加し、組換えタンパク質の生産を誘導した。誘導培養を18℃にて24時間行った。遠心分離(8,000rpm、10分、4℃)により培養液から菌体を回収し、Niカラムクロマトグラフィーの結合バッファー(20mMリン酸ナトリウム緩衝液、pH7.5、500mM塩化ナトリウム)10mLに懸濁し、ソニケーション(URTRA SONIC DISRUPTOR UR-200P、トミー精工社製)により菌体を破砕した。遠心分離(8,000rpm、10分、4℃)して得られた上清を、BL105A_1453を含む粗酵素液とした。
上記で得られた粗酵素液を結合バッファーで平衡化したNi-NTA Agaroseカラム(Φ1.0cm×4.0cm;QIAGEN)に供した。非吸着タンパク質を洗浄バッファー(20mMリン酸ナトリウム緩衝液、pH7.5、500mM塩化ナトリウム、50mMイミダゾール)により除去した後、20-500mMのイミダゾール直線濃度勾配により吸着タンパク質を溶出した(溶出バッファーA、20mMリン酸ナトリウム緩衝液、pH7.5、20mMイミダゾール;溶出バッファーB、20mMリン酸ナトリウム緩衝液、pH7.5、500mM イミダゾール;各60mL)。画分液量を洗浄では8mL、溶出では3mLとした。ONPG分解活性プレートアッセイにて活性が確認された画分(溶出fra.7-14)を回収した。回収した画分を透析膜(セルロースチューブ 36/32;Viskase Companies,Inc.)を用いて10mMリン酸ナトリウム緩衝液(pH6.5)1Lに対して1回、さらに同緩衝液5Lに対して2回透析した。透析後、Amicon Ultra-15(MWCO,100,000;Merck Millipore)を用いて1.5mLまで濃縮した。これをBL105A_1453精製酵素液とした。得られた精製酵素液に、終濃度50%となるようにグリセロールを添加し、-80℃にて保存した。精製酵素液をSDS-PAGEに供し、単一のバンドであることを確認した。
上記で調製したBL105A_1453精製酵素液および他のラクターゼ製剤(酵素液)について、乳糖分解試験を行った。市販の牛乳(明治社製、乳糖含有量は4.7質量%)1mLを1.5mLエッペンチューブに分注し、10℃にて10分間プレインキュベートした。これに各ラクターゼを終濃度0.01、0.02、0.03、0.04、0.06、0.08、0.12および0.16v/v%となるように緩衝液を用いて調整した各酵素液20μLを添加し、10℃にて48時間保持した。ブランクには、牛乳1mLに緩衝液20μLを添加したものを用いた。BL105A_1453については、製品(作り込み)活性を3500LYU/mLと想定した。反応停止は、20%スルホサリチル酸を1/20量添加することにより行った。なお、緩衝液には0.1mM塩化マンガンを含む0.1Mリン酸緩衝液(pH6.5)を用いた。
HPLCおよびHPAEC-PADを用いた各サンプルの糖分析を以下に従って行った。
超純水で5倍希釈したサンプルを孔径0.22μmのフィルターで濾過し、濾液をHPLCを用いて分析した。HPLC分析時の条件は以下のとおりである。
本体:高速液体クロマトグラフィー(HPLC)Waters2696
カラム:TRANSGENOMIC社製、CARBOSep CHO-620CA(φ6.5mm×300mm)、85℃
移動相:水
流速:0.4mL/分
検出器:RI
サンプル注入量:5μL
超純水で250倍希釈したサンプルを0.22μmのフィルターで濾過し、濾液をHPAEC-PADを用いて分析した。HPAEC-PAD分析時の条件は以下のとおりである。
本体:Dionex社製、ICS-6000+、AS-Ap オートサンプラー
カラム:Dionex社製、CarboPac PA1(φ4.0mm×250mm)、20℃
移動相:下記4液のグラジエント
A:100mM 水酸化ナトリウム溶液
B:100mM 水酸化ナトリウム含有600mM酢酸ナトリウム溶液
C:水
D:50mM 酢酸ナトリウム溶液
流速:1.0mL/分
検出器:パルスドアンペロメトリ、30℃
サンプル注入量:25μL
10℃において、各反応時間における牛乳中の乳糖濃度が0.1質量%または0.01質量%に達するラクターゼ活性(LYU/mL)を表1に示す。このラクターゼ活性は牛乳中の終濃度を示す。
測定対象物に含まれるタンパク質量当たりの乳糖分解能を比較するため、LYU活性を指標とした比活性を算出した。BL105A_1453酵素液および他のラクターゼ製剤のタンパク質の定量は、Bradford法に従った。
YNL 2精製酵素液およびBL105A_1453精製酵素液について、牛乳中における活性化因子を解析した。
具体的には、酵素液10μLを以下の各条件で得られる溶液190μLに加えた後、10℃または37℃で10分間保持した反応系において乳糖分解速度(反応速度)を算出した。
条件1:139mM 乳糖、0.5mM MES-NaOH(pH=6.5)
条件2:混合塩類(NaCl、KCl、MgCl2)含有139mM 乳糖(Na+:18.4mM、K+:39.6mM、Mg2+:4.25mM)
条件3:牛乳
条件4:分画牛乳
条件5:脱塩分画牛乳-1(電気透析により条件4の分子量<100の荷電成分を除去)
条件6:脱塩分画牛乳-2(イオン交換樹脂により4の荷電成分を除去)
乳糖分解速度は以下の手順で算出した。
酵素液10μLを上記の各条件で得られる溶液190μLに加えた後、10℃または37℃で10分間反応後、21%スルホサリチル酸を10μL加え、反応を停止した。遠心分離により回収したサンプル上清を超純水で10倍希釈した溶液50μLに、2M トリス塩酸緩衝液100μL(pH7.0)およびグルコース定量試薬 (グルコースCIIテストワコー)20μLを添加し、37°Cに1時間保持してA505を測定した。検量線(0-600μM グルコースとA505)に基づきA505からグルコース濃度を算出した。なお、検量線にはグルコース水溶液:牛乳上清=9:1の混合溶液を用いた。本条件下で1分間に1μmolの乳糖を加水分解する酵素量を1単位と定義した。得られた結果を表3および表4に示す。
BL105A_1453では分画牛乳のイオン交換樹脂による脱塩では139mM 乳糖のレベルまで活性が低下するが、電気透析による脱塩では活性の低下が穏やかであった。混合塩類の添加により、牛乳中の活性のレベルとなることから牛乳中の塩が活性化に働くと考えられるが、電気透析では除かれない成分が塩の代替として働く可能性も考えられる。
以下の各反応系において37℃でのo-ニトロフェニル-β-D-ガラクトピラノシド(ONPG) 分解速度(反応速度)を算出した。
反応系1:(Na+)(50μL)
2mM ONPG、10mM MES-NaOH(pH 6.0、5.3mM Na+を含む)、0-50mM NaCl、酵素
反応系2:(K+、Mg2+、Mn2+、Ca2+)(50μL)
2mM ONPG、10mM MES-NaOH(pH 6.0、6mM K+を含む)、0-50mM KCl、0-10mM MgCl2、0-0.1mM MnCl2または0-50mM CaCl2、酵素
ONPG分解速度は以下の手順で算出した。
上記反応系1または2を37℃で10分間反応後、1M 炭酸ナトリウム溶液100μLを添加し、A400を測定した。本条件下で1分間に1μmolのONPGを分解する酵素量を1単位と定義した。得られた結果を図3に示す。
<<至適pH>>
ラクターゼの至適pHは以下の方法で測定した。
各pHに調整した緩衝液 (0.1mM 塩化マンガンを含む0.1M リン酸ナトリウム緩衝液、pH4.5-9.5)により希釈したBL105A_1453酵素液を1.5mLチューブに150μL採り、緩衝液150μLと混和させた後、37℃で3分間プレインキュベートした。基質(ONPG 100mg/蒸留水100mL)300μLと37℃で1分間反応させ、0.2M 炭酸ナトリウム600μLを加えて反応を停止させた。反応液のOD420の吸光度から、ラクターゼ活性の値を算出した。ラクターゼ活性1単位は、10分間に測定値を1変化させるのに必要な酵素量と定義した。
得られた結果を図4に示した。BL105A_1453の至適pHは6.0であった。
ラクターゼのpH安定性は以下の方法で測定した。
BL105A_1453酵素液を各緩衝液(pH3.0-10.5)で10倍希釈し、37℃で30分間インキュベートした。3分間氷上で冷却した後、pH6.0の緩衝液でさらに200倍希釈した。希釈した酵素液を1.5mLチューブに300μL採り、緩衝液300μLと混和させた後、37℃で3分間プレインキュベートした。基質(ONPG100mg/蒸留水100mL)600μLと37℃で1分間反応させ、0.2M 炭酸ナトリウム1200μLを加えて反応を停止させた。反応液のOD420の吸光度から、ラクターゼ活性の値を算出した。ラクターゼ活性1単位は、10分間に測定値を1変化させるのに必要な酵素量と定義した。
ラクターゼのpH安定性は、ラクターゼの至適pHにおいて示した方法のうち、使用する緩衝液と、37℃で30分間インキュベートさせた以外は同様の方法で測定することができる。
各pHにおける緩衝液は以下のものを用い、pHは酵素希釈時の実測値でプロットした。
・pH3.5~5.5
:0.1mM 塩化マンガンを含む0.1M 酢酸ナトリウム緩衝液
・pH5.5~9.0
:0.1mM 塩化マンガンを含む0.1M リン酸ナトリウム緩衝液
・pH8~10.5
:0.1mM 塩化マンガンを含む0.1M グリシン・水酸化ナトリウム緩衝液
得られた結果を図5に示した。BL105A_1453の安定域はpH5.2-8.4であった。
ラクターゼの至適温度は以下の方法で測定した。
pH6.0のリン酸ナトリウム緩衝液で2000倍希釈したBL105A_1453酵素液を300μL採り、緩衝液300μLと混和させた後、4、10、15、20、25、30、35、37、40、45、50、55、60℃で3分間プレインキュベートした。その後、各温度にてpH安定性試験と同様にして活性測定を行った。
得られた結果を図6に示した。図6では、37℃における活性を基準(相対活性100%)とした。BL105A_1453の至適温度は50℃であった。
ラクターゼの温度安定性は以下の方法で測定した。
BL105A_1453酵素液をpH6.0の緩衝液で10倍希釈し、37、50、55、60、65、70℃で0、5、10、30、60分間インキュベートした。3分間氷上で冷却した後、pH6.0の緩衝液でさらに200倍希釈した。希釈した酵素液を試験管に300μL採り、緩衝液300μLと混和させた後、37℃で3分間プレインキュベートした。その後、pH安定性試験と同様にして活性測定を行った。
得られた結果を図7に示した。BL105A_1453は50℃にて1時間反応後も100%のラクターゼ残存活性を示した。
30または50w/v% 乳糖存在下でBL105A_1453をそれぞれ作用させたところ、3糖以上のガラクトオリゴ糖を最大20%生成することを確認した(ガラクトオリゴ糖の収率として)。BL105A_1453によって生成したガラクトオリゴ糖の主要構造は3’-ガラクトシルラクトースであった(図8下段)。図8上段に示すように、Bacillus circulans由来のガラクトオリゴ糖生成酵素(製品名:ビオラクタ)の主要構造は4’-ガラクトシルラクトースであることから、生成するガラクトオリゴ糖の種類が異なることを確認した。
なお、3’-ガラクトシルラクトースは4’-ガラクトシルラクトースと同様、ヒトの腸内におけるビフィズス菌増殖効果が期待されている物質である。
ここで、3糖のガラクトオリゴ糖を製造する場合、2分子の乳糖から1分子のグルコース及び1分子の3糖のガラクトオリゴ糖が生じる。この時のガラクトオリゴ糖の理論収率は約74質量%である。4糖のガラクトオリゴ糖を製造する場合、3分子の乳糖から2分子のグルコース及び1分子の4糖のガラクトオリゴ糖が生じる。この時のガラクトオリゴ糖の理論収率は約65質量%である。したがって乳糖からガラクトオリゴ糖を製造する場合、3糖のガラクトオリゴ糖のみを製造することが収率の点で最も効率的である。ここでガラクトオリゴ糖の収率(質量%)とは、「ガラクトオリゴ糖の生成量」を「乳糖の消費量」で除した百分率を意味する。生成したガラクトオリゴ糖は、HPLCにより測定することができる。具体的には、WO2019/194062記載の方法を採用すればよい。
市販の牛乳(明治社製)にスターター(乳酸菌 YF-L812株 10mg/100g、ビフィズス菌 BB-12株 5mg/100g)を入れて撹拌、分注後、BL105A_1453酵素液を製品活性 5200LYU/mLとして0.02、0.06%となるように添加した。対照として、YNL 2 0.02%添加区とラクターゼB(Bifidobacterium bifidum由来酵素)0.02%添加区を設けた。発酵開始から0,2,4時間後にサンプリングを行い、糖分析により残存乳糖濃度(質量%)を算出した。ただし、BL105A_1453添加区は発酵が早く進んだため、3時間経過時にもサンプリングを行った。発酵終了後、サンプルを10℃に移し、24、48、72時間後の残存乳糖濃度を算出した。糖分析に供するサンプルは全て水で3倍希釈し、スルホサリチル酸により除タンパク質処理をした。その他の糖分析の条件は上述した<<HPLC分析>>に従った。
以上の結果から、BL105A_1453をスターターと同時に添加し発酵乳を得る方法によって、発酵段階において、効率的に乳糖を分解することができる。これによって、発酵乳製造段階において別途の工程を必要とせず、ラクトースフリーの発酵乳を安定的に製造することができる。
BL105A_1453およびYNL 2製剤を組み合わせて牛乳中の乳糖分解試験を行った。終濃度0.04%(YNL 2と1453を合わせて0.04%)となるように各酵素20μLを牛乳に添加し、10℃にて48時間保持した。このとき、BL105A_1453の製品活性を5,200LYU/mLと想定した。その他の条件および糖分析は上述した<牛乳中での乳糖分解の経時変化>、<乳糖分解率の算出方法>、<<HPLC分析>>及び<<HPAEC-PAD分析>>に従った。
得られた結果を図10に示した。乳糖分解における初速度はYNL 2濃度依存的に速くなった一方、最終分解率はBL105A_1453濃度依存的に高くなった。なお、図10のうち、乳糖濃度0.01%未満がラクトースフリーの領域である。
上記の結果から、ラクターゼとして複数の酵素を使用することで、所望の結果を得やすくなることを確認した。
Claims (11)
- ラクターゼ活性として、以下の(1)~(6)に記載の活性のうち、いずれか1つ、または複数の組み合わせを有する、ラクターゼ。
(1)牛乳に前記ラクターゼを添加したとき、10℃、16時間後における残存乳糖濃度が0.1%以下に達する前記ラクターゼのタンパク質の添加量が15.1mg/L以下である。
(2)牛乳に前記ラクターゼを添加したとき、10℃、16時間後における残存乳糖濃度が0.01%以下に達する前記ラクターゼのタンパク質の添加量が30.2mg/L以下である。
(3)牛乳に前記ラクターゼを添加したとき、10℃、24時間後における残存乳糖濃度が0.1%以下に達する前記ラクターゼのタンパク質の添加量が10.1mg/L以下である。
(4)牛乳に前記ラクターゼを添加したとき、10℃、24時間後における残存乳糖濃度が0.01%以下に達する前記ラクターゼのタンパク質の添加量が15.1mg/L以下である。
(5)牛乳に対して、終濃度1.4LYU/mlとなる量を添加したときの、10℃、24時間後における残存乳糖濃度が0.1%以下に達する。
(6)牛乳に対して、終濃度2.1LYU/mlとなる量を添加したときの、10℃、24時間後における残存乳糖濃度が0.01%以下に達する。 - 以下の(i)~(iii)のいずれか一つから選択される請求項1に記載のラクターゼ。
(i)配列番号1で表されるアミノ酸配列からなるタンパク質
(ii)配列番号1で表されるアミノ酸配列の1~数個のアミノ酸残基が欠失、置換または挿入されたアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
(iii)配列番号1で表されるアミノ酸配列の70%以上の同一性を有するアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質 - 請求項1に記載の牛乳が下記の一つ以上を充足する、請求項1または2に記載のラクターゼ。
(A)牛乳中に含まれる固形分量は0.1質量%以上30質量%以下
(B)牛乳中に含まれる乳糖量は0.1質量%以上30質量%以下
(C)牛乳中に含まれるタンパク量は0.1質量%以上30質量%以下
(D)牛乳中に含まれる脂肪分量は0.1質量%以上30質量%以下 - 請求項1~3のいずれか1項に記載のラクターゼと、
水、塩、賦形剤、懸濁剤、緩衝剤、安定化剤、保存剤および生理食塩水から選択される少なくとも一つと、
を含有するラクターゼ製剤。 - 前記塩が塩化マグネシウム、塩化ナトリウム、塩化カリウムおよび塩化カルシウムからなる群より選ばれる1種以上である、請求項4に記載のラクターゼ製剤。
- 請求項1~3のいずれか1項に記載のラクターゼと、当該ラクターゼと由来または性質の異なる第二のラクターゼと、
を含有するラクターゼ製剤。 - 以下の(i)、(ii)または(iii)のタンパク質をコードする遺伝子。
(i)配列番号1で表されるアミノ酸配列からなるタンパク質
(ii)配列番号1で表されるアミノ酸配列の1~数個のアミノ酸残基が欠失、置換または挿入されたアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質
(iii)配列番号1で表されるアミノ酸配列の70%以上の同一性を有するアミノ酸配列からなり、かつラクターゼ活性を有するタンパク質 - 下記(a)~(d)のいずれかのDNAからなる遺伝子である請求項7に記載の遺伝子。
(a)配列番号2で示される塩基配列からなるDNA
(b)配列番号2で示される塩基配列において1~数個の塩基が欠失、置換または付加された塩基配列からなり、かつラクターゼ活性を有する前記タンパク質をコードするDNA
(c)配列番号2で示される塩基配列に対して70%以上の配列同一性を有する塩基配列からなり、かつラクターゼ活性を有する前記タンパク質をコードするDNA
(d)配列番号2で示される塩基配列に相補的な塩基配列からなるDNAとストリンジェントな条件下でハイブリダイズし、かつラクターゼ活性を有する前記タンパク質をコードするDNA - 請求項7または8に記載の遺伝子を有する組み換えベクター。
- 請求項9に記載の組み換えベクターで形質転換した形質転換体。
- 原料乳に、請求項1乃至3のいずれか1項に記載の前記ラクターゼまたは請求項4または5に記載の前記ラクターゼ製剤を添加する工程と、
前記原料乳に、前記ラクターゼまたは前記ラクターゼ製剤に含まれるラクターゼを所定の時間だけ反応させる工程と、
を備える、乳糖分解乳の製造方法。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202280059879.XA CN117980483A (zh) | 2021-09-07 | 2022-09-07 | 乳糖酶、乳糖酶制剂、基因、重组载体和转化体 |
JP2023546967A JPWO2023038057A1 (ja) | 2021-09-07 | 2022-09-07 |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021145630 | 2021-09-07 | ||
JP2021-145630 | 2021-09-07 | ||
JP2022-033806 | 2022-03-04 | ||
JP2022033806 | 2022-03-04 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023038057A1 true WO2023038057A1 (ja) | 2023-03-16 |
Family
ID=85506366
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/033563 WO2023038057A1 (ja) | 2021-09-07 | 2022-09-07 | ラクターゼ、ラクターゼ製剤、遺伝子、組み換えベクターおよび形質転換体 |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPWO2023038057A1 (ja) |
WO (1) | WO2023038057A1 (ja) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004534527A (ja) | 2001-04-04 | 2004-11-18 | デーエスエム イーペー アセッツ ベスローテン フェンノートシャップ | 精製ラクターゼ |
JP2016208998A (ja) * | 2011-03-14 | 2016-12-15 | 合同酒精株式会社 | ラクターゼ製剤 |
WO2019194062A1 (ja) | 2018-04-05 | 2019-10-10 | 合同酒精株式会社 | Paenibacillus pabuli由来のガラクトオリゴ糖を製造可能な酵素、およびガラクトオリゴ糖を製造する方法 |
-
2022
- 2022-09-07 WO PCT/JP2022/033563 patent/WO2023038057A1/ja active Application Filing
- 2022-09-07 JP JP2023546967A patent/JPWO2023038057A1/ja active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004534527A (ja) | 2001-04-04 | 2004-11-18 | デーエスエム イーペー アセッツ ベスローテン フェンノートシャップ | 精製ラクターゼ |
JP2016208998A (ja) * | 2011-03-14 | 2016-12-15 | 合同酒精株式会社 | ラクターゼ製剤 |
WO2019194062A1 (ja) | 2018-04-05 | 2019-10-10 | 合同酒精株式会社 | Paenibacillus pabuli由来のガラクトオリゴ糖を製造可能な酵素、およびガラクトオリゴ糖を製造する方法 |
Non-Patent Citations (4)
Title |
---|
J. MOL. BIOL., vol. 215, 1990, pages 403 - 410 |
J. SAMBROOK: "Molecular Cloning: A Laboratory Manual", 1989 |
KARLINALTSCHUL, PRO. NATL. ACAD. SCI. USA, vol. 90, 1993, pages 5873 - 5877 |
KEISUKE MATSUMOTO ET.AL.: "Characterization and utilization of β-galactosidase from Lactobacillus and Bifidobacterium", RAKUNO KAGAKU, SHOKUHIN NO KENKYU - JAPANESE JOURNAL OF DAIRY AND FOOD SCIENCE, NIHON RAKUNO KAGAKKAI, SENDAI, JP, vol. 39, no. 6, 1 January 1990 (1990-01-01), JP , pages A - A-248, XP009544334, ISSN: 0385-0218 * |
Also Published As
Publication number | Publication date |
---|---|
JPWO2023038057A1 (ja) | 2023-03-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DK202000111Y3 (da) | Polypeptider med transgalactosyleringsaktivitet | |
JP5643756B2 (ja) | バチルス・サーキュランス由来のβ−ガラクトシダーゼ | |
AU2018251957B2 (en) | Lactase enzymes with improved properties | |
JP4931914B2 (ja) | 非リン酸化性ラクトースパーミアーゼを有する乳酸菌の変異株 | |
WO2014084340A1 (ja) | ヨーグルトおよびその製造方法、乳酸菌体外機能性産生物製造方法、ならびに乳酸菌体外機能性産生物増産剤 | |
JP2022504684A (ja) | 酸性phで改善された特性を持つラクトース分解酵素 | |
WO2019194062A1 (ja) | Paenibacillus pabuli由来のガラクトオリゴ糖を製造可能な酵素、およびガラクトオリゴ糖を製造する方法 | |
AU2022205242A1 (en) | Lactase enzymes with improved properties | |
KR101121161B1 (ko) | 고당전이 활성의 신규한 베타-갈락토시다제 및 그 용도 | |
CA2808817A1 (en) | Fermented milk having little lactose and method for producing same | |
WO2023038057A1 (ja) | ラクターゼ、ラクターゼ製剤、遺伝子、組み換えベクターおよび形質転換体 | |
US20210032615A1 (en) | Lactase enzymes with improved properties | |
AU2018250886C1 (en) | Lactase enzymes with improved activity at low temperatures | |
JP5738561B2 (ja) | 新規環状バクテリオシン | |
CN117980483A (zh) | 乳糖酶、乳糖酶制剂、基因、重组载体和转化体 | |
US10526592B2 (en) | Beta-galactosidase variant having high transglycosylation activity, and use thereof | |
RU2806709C2 (ru) | Ферменты лактазы с улучшенными свойствами | |
RU2814542C2 (ru) | Ферменты лактазы с улучшенными свойствами при кислом pH | |
WO2021210539A1 (ja) | 発酵乳及びその製造方法、並びに脱リン酸乳 | |
RU2788608C2 (ru) | Ферменты лактазы с улучшенными свойствами | |
WO2018228966A1 (en) | Frozen enzyme pellets | |
RU2800427C2 (ru) | Ферменты лактазы с улучшенной активностью при низких температурах | |
JP2021093954A (ja) | ガラクトオリゴ糖を製造可能な酵素、およびガラクトオリゴ糖を製造する方法 | |
CN114514317A (zh) | 使用调控改变的菌株生产乳糖酶 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22867379 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2023546967 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2022867379 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2022867379 Country of ref document: EP Effective date: 20240408 |