• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.57-65
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• 2015

β-Glucosidase production by the white rot fungus Flammulina velutipes CFK 3111 was evaluated using different carbon and nitrogen sources under submerged fermentation. Maximal extracellular enzyme production was 1.6 U/ml, corresponding to a culture grown in sucrose 40 g/land asparagine 10 g/l. High production yield was also obtained with glucose 10 g/land asparagine 4 g/l medium (0.5 U/ml). Parameters affecting the enzyme activity were studied using p-nitrophenyl-β-_D-glucopyranoside as the substrate. Optimal activity was found at 50℃ and pHs 5.0 to 6.0. Under these conditions, β-glucosidase retained 25% of its initial activity after 12 h of incubation and exhibited a half-life of 5 h. The addition of MgCl₂, urea, and ethanol enhanced the β-glucosidase activity up to 47%, whereas FeCl₂, CuSO₄, Cd(NO₃)₂, and cetyltrimethylammonium bromide inflicted a strong inhibitory effect. Glucose and cellobiose also showed an inhibitory effect on the β-glucosidase activity in a concentration-dependent manner. The enzyme had an estimated molecular mass of 75 kDa. To the best of our knowledge, F. velutipes CFK 3111 β-glucosidase production is amongst the highest reported to date, in a basidiomycetous fungus.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.469-478
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• 2015

In spite of the reported probiotic effects, Bifidobacterium bifidum BGN4 (BGN4) showed no βglucosidase activity and failed to biotransform isoflavone glucosides into the more bioactive aglycones during soy milk fermentation. To develop an isoflavone-biotransforming BGN4, we constructed the recombinant B. bifidum BGN4 strain (B919G) by cloning the structural β-glucosidase gene from B. lactis AD011 (AD011) using the expression vector with the constitutively active promoter 919 from BGN4. As a result, B919G highly expressed β-glucosidase and showed higher β-glucosidase activity and heat stability than the source strain of the β-glucosidase gene, AD011. The biotransformation of daidzin and genistin compounds using the crude enzyme extract from B919G was completed within 4 h, and the bioconversion of daidzin and genistin in soy milk during fermentation with B919G also occurred within 6 h, which was much faster and higher than with AD011. The incorporation of this β-glucosidase-producing Bifidobacterium strain in soy milk could lead to the production of fermented soy milk with an elevated amount of bioavailable forms of isoflavones as well as to the indigenous probiotic effects of the Bifidobacterium strain.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1206-1215
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• 2016

Ginsenosides are the major active ingredients in ginseng used for human therapeutic plant medicines. One of the most well-known probiotic bacteria among the various strains on the functional food market is Lactobacillus rhamnosus GG. Biocatalytic methods using probiotic enzymes for producing deglycosylated ginsenosides such as Rd have a growing significance in the functional food industry. The addition of 2% cellobiose (w/v) to glucose-free de Man-Rogosa-Sharpe broths notably induced β-glucosidase production from L. rhamnosus GG. Enzyme production and activity were optimized at a pH, temperature, and cellobiose concentration of 6.0, 40℃, and 2% (w/v), respectively. Under these controlled conditions, β-glucosidase production in L. rhamnosus GG was enhanced by 25-fold. Additionally, whole-cell homogenates showed the highest β-glucosidase activity when compared with disrupted cell suspensions; the cell disruption step significantly decreased the β-glucosidase activity. Based on the optimized enzyme conditions, whole-cell L. rhamnosus GG was successfully used to convert ginsenoside Rb1 into Rd.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.44-49
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• 2015

Thermostable enzymes derived from Thermotoga maritima have attracted worldwide interest for their potential industrial applications. Structural analysis and docking studies were preformed on T. maritima β-glucosidase enzyme with cellobiose and pNP-linked substrates. The 3D structure of the thermostable β-glucosidase was downloaded from the Protein Data Bank database. Substrates were downloaded from the PubCehm database and were minimized using MOE software. Docking of BglA and substrates was carried out using MOE software. After analyzing docked enzyme/substrate complexes, it was found that Glu residues were mainly involved in the reaction, and other important residues such as Asn, Ser, Tyr, Trp, and His were involved in hydrogen bonding with pNP-linked substrates. By determining the substrate recognition pattern, a more suitable β-glucosidase enzyme could be developed, enhancing its industrial potential.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1536-1542
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• 2020

Dekkera anomala YAE-1 strain separated from "airag" (Mongolian fermented mare's milk) produces β-glucosidase, which can convert ginsenoside Rb₁ from Panax ginseng. Ginseng- derived bioactive components such as ginsenoside Rb₁ have various immunological and anticancer activities. Airag was collected from five different mare milk farms located near Ulaanbaatar, Mongolia. YAE-1 strains were isolated from airag to examine the hydrolytic activities of β-glucosidase on Korean Panax ginseng using an API ZYM kit. Supernatants of selected cultures having β-glucosidase activity were examined for hydrolysis of the major ginsenoside Rb₁ at 40℃, pH 5.0. The YAE-1 strain was found to be nearly identical at 99.9% homology with Dekkera anomala DB-7B, and was thus named Dekkera anomala YAE-1. This strain exerted higher β-glucosidase activity than other enzymes. Reaction mixtures from Dekkera anomala YAE-1 showed great capacity for converting ginsenoside Rb₁ to ginsenoside Rd. The β-glucosidase produced by Dekkera anomala YAE-1 was able to hydrolyze ginsenoside Rb₁ and convert it to Rd during fermentation of the ginseng. The amount of ginsenoside Rd was highly increased from 0 to 1.404 mg/ml in fermented 20% ginseng root at 7 days.

• Journal of the Korean Wood Science and Technology
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• 제51권4호
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• pp.270-282
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• 2023

Lower termites need symbiotic microbes for cellulose digestion. Elizabethkingia miricola strain BM10 has been proposed as a symbiotic microbe that assists in low-temperature digestion and metabolism of Reticulitermes speratus KMT1, a termite on Bukhan Mountain, Seoul, Korea. In E. miricola strain BM10, β-glucosidase genes expressed at 10℃ were identified, and the psychrophilic enzymatic characteristic was confirmed by heterogeneously expressed proteins. Crude β-glucosidase in the culture broth of E. miricola strain BM10 showed specific enzymatic properties, and its substrate affinity was 4.69 times higher than that of Cellic CTec2. Among the genes proposed as β-glucosidase, two genes, bglB_1 and bglA_2, whose gene expression was more than doubled at 10℃ than at 30℃, were identified. They were heterogeneously expressed in Escherichia coli and identified as psychrophilic enzymes with an optimal reaction temperature of about 20℃-25℃. In this study, E. miricola strain BM10, a symbiotic bacterium of lower termites, produced psychrophilic β-glucosidases that contribute to the spread of the low-temperature habitat of a lower termite, R. speratus KMT1.

• 한국약용작물학회지
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• 제28권5호
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• pp.371-378
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• 2020

Background: In this study, the radix of Astragalus membranaceus Bunge extract fermented by Saccharomyces cerevisiae, Weissella cibaria, and Pediococcus pentosaceus to increase the levels of isoflavonoid aglycone contents. Methods and Results: In order to change the in isoflavonoids, we fermented the radix of A. membranaceus extracts with microorganisms that have β-glucosidase activity. Besed on the β-glucosidase activity, we selected three strains, Weissella cibaria, Pediococcus pentosaceus, and Saccharomyces cerevisiae. HPLC analysis revealed that the levels of isoflavonoid aglycones were increased in all fermentation cases, and the extracts fermented by S. cerevisiae showed the highest levels of isoflavonoid aglycones. We evaluated the antioxidant activity, anti-wrinkle effects and whitening effects of the S. cerevisiae-fermented extracts using the DPPH assay, tyrosinase inhibition activity assay, and collagenase inhibition activity assay. We confirmed higher activity in S. cerevisiae-fermented extracts than in control, with the half maximal inhibitory concentration (IC₅₀) value of 565.1 ± 59.1 ㎍/㎖ in DPPH radical scavenging activity, tyrosinase inhibition rate of 78.4 ± 0.9%, and collagenase inhibition rate of 83.8 ± 1.1%. Conclusions: We selected three stains of microorganisms showing high β-glucosidase activity, W. cibaria, P. pentosaceus and S. cerevisiae. Isoflavonoid glycones in the radix of A. membranaceus were converted to isoflavonoid aglycones by fermentation. In addition, the fermented radix of A. membranaceus exhibited antioxidant activity, anti-wrinkle effect, whitening effect and radical scavenging activity.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.125-125
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• 2022

식물 내에는 배당체 형태의 생리활성 물질들이 다량 존재하고 있으며, 비배당체로 전환하였을 경우 생리활성이나 투과성이 증대된다는 연구들이 보고되어 있다. 따라서 본 연구에서는 고활성 β-glucosidase 활성을 갖는 균주를 선별함으로써 식물 내의 비배당체 활성 성분을 증대시키는 데 활용하고자 한다. 균주는 전남지역 제조된 막걸리부터 분리하였다. 분리된 균주는 성장 속도 등 산업적으로 활용될 수 있는 가치를 평가하여 11종 22점의 균주를 분리하고, 16S rRNA분석을 통해 균주를 동정하였다. 동정된 균주를 이용하여 β-glucosidase의 활성을 평가하여 고활성 균주를 1종을 선별하였다. 선별된 균주는 다른 균주에 비하여 상대적 활성이 57% ~ 99%정도 활성이 높았으며, 공시 균주와 비교하였을 때도 상대 활성이 높은 았다. 선별된 균주의 특성을 규명하기 위하여 glycerol, L-arbinose를 비롯한 49가지의 탄수화물의 대사 활성을 확인해본 결과 25가지의 탄수화물 대사 활성을 가지고 있는 것을 알수 있었다. 또한 Lipase, β-glucosidase 19가지의 다양한 효소활성을 확인해본 결과 8종의 효소활성이 있음을 확인할 수 있었다.

• 한국식품영양과학회지
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• 제33권2호
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• pp.439-442
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• 2004

재래식 된장으로부터 혈전용해능과 $\beta$-glucosidase효소를 생산하는 미생물을 분리하였으며, 분리한 균의 형태학적, 생화학적인 분류를 수행하여 Bacillus속으로 동정하였으며, Bacillus sp. KHI-15로 명명하였다 그리고 분리한 균주의 효소생산을 위한 배지조건과 배양조건을 측정하였다. 선발균주는 2% glucose, 0.5% yeast extract, 0.1% calcium chloride의 최적 배지에서 최대의 효소생산을보였다. 초기 pH7∼8과 4$0^{\circ}C$에서는 혈전용해능이 최대를 보였으며, 초기 pH6∼8과 30∼4$0^{\circ}C$에서는 $\beta$-glucosidase 효소활성의 생산이 가장 높았다.

• Journal of Dairy Science and Biotechnology
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• 제37권4호
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• pp.223-236
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• 2019

본 연구는 김치로부터 비만 억제능력이 있는 젖산균을 분리 및 동정하고, 이 균주의 생리적 특성을 규명하여 상업적으로의 이용가능성을 검토하고자 실시하였다. 이를 위해 Modified MRS 분별배지를 사용하여 노란색 집락을 형성하는 균주를 대상으로 각각 α-amylase inhibitory activity, α-glucosidase inhibitory activity와 단쇄지방산 생산이 우수한 균주를 선발한 결과, KI69 균주가 최종 선발되었다. KI69 균주는 α-amylase억제활성 91.17±2.23%, α-glucosidase 억제활성 98.71±4.23%, 단쇄지방산인 프로피온산, 에세트산, 브티르산이 MRS broth에서 각각 8.78±1.12 ppm, 1.34±0.07%(w/v), 0.876±0.003 g/kg이 나타났으며, 동정결과 L. plantarum으로 판명되었고, L. plantarum KI69로 명명하였다. L. plantarum KI69는 답즙산과 산성의 pH에서 모두 우수한 생존력을 나타내었고, 효소활성은 β-galactosidase, β-glucosidase와 N-acetyl-β-glucosaminidase에 대해 높은 효소 활성을 나타내었다. 항생제 내성 실험 결과 vancomycin에 내성이 있는 반면 penicillin-G와rifampicin에 감수성을 나타냈으며, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes와 Staphyloccous aureus에 대해 각각 15.44%, 50.79%, 58.62%와 37.85%의 억제 효과를 지니고 있는 것으로 나타났다. 장 부착성은 대조구인 L. rhamnosus GG보다 우수하였다.