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Leuconostoc lactis CCK940의 Glucansucrase 활성에 의한 올리고당 생산 최적화
이설희 ( Sulhee Lee ),박영서 ( Young-seo Park ) 한국산업식품공학회 2017 산업 식품공학 Vol.21 No.4
Glucansucrase is an enzyme classified as a glycoside hydrolase (GH) 70 family, which catalyzes the synthesis of glucooligosaccharides with a low molecular weight using sucrose as a donor of D-glucopyranose and maltose as a carbohydrate acceptor. In this study, glucansucrase-producing lactic acid bacteria strain was isolated from the fermented foods collected in traditional markets, and the optimum conditions for the oligosaccharide production were investigated. The strain CCK940 isolated from Chinese cabbage kimchi was selected as an oligosaccharide-producing strain due to its high glucansucrase activity, with 918.2 mU/mL, and identified as Leuconostoc lactis. The optimum conditions for the production of oligosaccharides using Leu. lactis CCK940 were to adjust the initial pH to 6.0, add 5% (w/v) sucrose and 10% (w/v) maltose as a donor and acceptor molecules, respectively, and feed 5% (w/v) sucrose at 4 and 8 h of cultivation. When Leu. lactis CCK940 was cultured for 12 h at optimum conditions, at least four oligosaccharides with a polymerization degree of 2-4 were produced.
이선,탄한,조재영,김지연,문영환,염수청,김근중,김도만 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1
95.3% of the sucrose in a feed batch fermentation (300 g/L) was hydrolyzed by Leuconostoc mesenteroides subp. mesenteroides NRRL B-23188 glucansucrase. Further, the glucose of sucrose formed glucooligosaccharides (GOS) of degree of polymerization (DP) over 2, together with 91.6% of the maltose (200 g/L). Lime saccharate (lime sucrate) was used to control the pH during fermentation. The GOS products had DP between 2 and 7. When Streptococcus mutans mutansucrase (0.1 U/mL) reacted with 0.1% sucrose, addition of 0.1 ~ 10% GOS to the mutansucrase reaction digest resulted in a 56 ~ 90% reduction of mutan formation. GOS also reduced E. coli (72.2%) and Salmonella sp. (over 40.0%) growth, when 2.5% GOS was used as a single carbon source, compared to growth using glucose. The calculated glycemic index and glycemic load of GOS was 8 and 1, respectively, based on a 10 g carbohydrate serving. GOS was calculated to have 2.43 kcal/g. After a glucose tolerance test was performed using C57BL/6 mice, we found that mice treated with GOS showed a 59.4% lower increase in plasma glucose than those treated with maltose.
Purification and characterization of a novel glucansucrase from Leuconostoc lactis EG001
Kim, Y.-M.,Yeon, M.J.,Choi, N.-S.,Chang, Y.-H.,Jung, M.Y.,Song, J.J.,Kim, J.S. G. Fischer 2010 MICROBIOLOGICAL RESEARCH Vol.165 No.5
A gene encoding glucansucrase was identified in Leuconostoc lactis EG001 isolated from lactic acid bacteria (LAB) in Kimchi, a traditional Korean fermented food. The L. lactis EG001 glucansucrase gene consists of 4503bp open reading frame (ORF) and encodes an enzyme of 1500 amino acids with an apparent molecular mass of 165kDa. The deduced amino-acid sequence showed the highest amino-acid sequence identity (75%) to that of dextransucrase of L. mesenteroides. The gene was cloned and over-expressed in Escherichia coli strain. The recombinant enzyme was purified via Ni-NTA affinity chromatography and its enzymatic properties were characterized. The enzyme exhibited optimum activity at 30<SUP>o</SUP>C and pH 5.0. In addition, the enzyme was able to catalyze the glycosylation of l-ascorbic acid to l-ascorbic acid 2-glucoside. The glycosylated product via EG001 glucansucrase has the potential as an antioxidant in industrial applications.
강희경,Thi Thanh Hanh Nguyen,Ha-Na Jeong,Min-Eon Park,김도만 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.4
Leuconostoc mesenteroides LM34 was isolatedfrom kimchi, a traditional fermented Korean food. L. mesenteroides LM34 produced extracellular glucansucrase(DSRLM34), which is responsible for the synthesis ofsoluble glucan using sucrose. The DSRLM34 gene consistsof a 4,503 bp open reading frame (ORF) and encodes anenzyme of 1,500 amino acids with an apparent molecularmass of 165 kDa. The deduced amino-acid sequenceshowed the highest amino-acid sequence identity (98%) tothat of glucansucrase of Lactobacillus lactis. The gene wasover-expressed in Escherichia coli strain and the recombinantenzyme (rDSRLM34) was purified. Both DSRLM34 andrDSRLM34 synthesized glucan mainly containing α-1, 6glucosidic linkage and branched α-1, 3 glucosidic linkages. The enzyme exhibited optimum activity at 30oC andpH 5.0. DSRLM34 has promising potential as a thickeningagent in sucrose-supplemented milk.
Synthesis of Oligosaccharide-containing Orange Juice Using Glucansucrase
탄한,서예슬,조재영,이선,Ghahyun J. Kim,윤종원,안승현,황경환,박준승,장태수,김도만 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.3
Orange juice is a well-accepted fruit juice, and is a natural source of various vitamins, especially vitamin C, as well as sugar, potassium, thiamine, folate, flavonoids and antioxidants. The respective fructose, glucose, and sucrose concentrations were 9.3, 22.9, and 48.1 g/L in the original orange juice used in this study, and 183.4, 170.1, and 142.8 g/L after concentration. Over 97% of the sucrose in the juice was enzymatically converted to glucooligosaccharides upon addition of 3 U/mL dextransucrase, prepared from Leuconostoc mesenteroides 512FMCM, at 16oC. The synthesized oligosaccharides comprised 35.0% of the total saccharides in the concentrated juice and 31.7% in the original juice. The optimum conditions for oligosaccharide synthesis using the concentrated juice were 35.2 × 10−1 U/mL dextransucrase and 1% Ca(OH)2. The calories in the original and modified concentrated orange juices were 325.4 and 246.7 kcal/L, respectively. Compared to the original concentrated juice, the enzyme-modified concentrated juice prevented the formation of 62.7% of the insoluble glucan resulting from addition of mutansucrase, produced by Streptococcus mutans.
Kang, Hee Kyoung,Kimura, Atsuo,Kim, Doman American Chemical Society 2011 Journal of agricultural and food chemistry Vol.59 No.8
<P>The variations in glucosidic linkage specificity observed in products of different glucansucrases appear to be based on relatively small differences in amino acid sequences in their sugar-binding acceptor subsites. Various amino acid mutations near active sites of DSRBCB4 dextransucrase from <named-content content-type='genus-species' xlink:type='simple'>Leuconostoc mesenteroides</named-content> B-1299CB4 were constructed. A triple amino acid mutation (S642N/E643N/V644S) immediately next to the catalytic D641 (putative transition state stabilizing residue) converted DSRBCB4 enzyme from the synthesis of mainly α-(1→6) dextran to the synthesis of α-(1→6) glucan containing branches of α-(1→3) and α-(1→4) glucosidic linkages. The subsequent introduction of mutation V532P/V535I, located next to the catalytic D530 (nucleophile), resulted in the synthesis of an α-glucan containing increased branched α-(1→4) glucosidic linkages (approximately 11%). The results indicate that mutagenesis can guide glucansucrase toward the synthesis of various oligosaccharides or novel polysaccharides with completely altered linkages without compromising high transglycosylation activity and efficiency.</P>