• Journal of Microbiology and Biotechnology
• /
• 제8권2호
• /
• pp.141-145
• /
• 1998

Overproduction of intracellular ${\beta}$-glucosidase was attempted by modifying the promoter region of a ${\beta}$-glucosidase gene cloned from Cellulomonas fimi and expressing it in Bacillus subtilis DB 104. A strong engineered promoter, BJ27UΔ88, was fused to the ${\beta}$-glucosidase gene after removing its native promoter. An effective Shine-Dalgamo sequence (genel0 of phage T7) was inserted between the promoter and the ${\beta}$-glucosidase structural gene. The modified gene was overexpressed in B. subtilis and produced 1121.5 units of ${\beta}$-glucosidase per mg protein which is about $12\%$ of total intracellular protein. Secretion of overproduced intracellular ${\beta}$-glucosidase was attempted by using the signal sequence of the Bacillus endoglucanase gene as well as an in-frame hybrid protein of endoglucanase. The hybrid protein was normally secreted into the culture medium and still retained ${\beta}$-glucosidase activity.

• 한국미생물·생명공학회지
• /
• 제17권3호
• /
• pp.202-206
• /
• 1989

토양으로부터 $\alpha$-D-Glucosidase Inhibitor를 강력히 분비하는 방선균속 균주를 분리한 후 균의 형태학적특성, 배양성 및 생리화학적 특성을 조사하여 동정한 결과 Streptomyces flavovirens 또는 그 근연균으로 동정되었다.

• Journal of Microbiology and Biotechnology
• /
• 제12권6호
• /
• pp.895-900
• /
• 2002

A soil microorganism producing ${\alpha}$- and ${\beta}$-glucosidase inhibitors was identified as Bacillus lentimorbus, based on the fatty acid and morphological analyses, along with biochemical and physiological tests. The ${\alpha}$-glucosidase inhibitor was highly produced by this strain in a culture medium containing $0.25\%$ of sodium glutamate and $0.5\%$ of glucose, pH 8.0 at $30^{\circ}C$ for 2 days. The ${\alpha}$-glucosidase inhibitor from culture filtrate of his strain was identified as water soluble, organic solvent nonextractable, and heat stable. In addition to ${\alpha}$-glucosidase inhibitor, this strain also produced ${\beta}$-glucosidase inhibitor in he same culture medium and this inhibitor showed an antifugal activity against Botrytis cinerea. While the production of ${\alpha}$- glucosidase inhibitor was decreased by a glucose concentration higher than $1\%$, the production of ${\beta}$-glucosidase inhibitor was lot Influenced by a glucose concentration higher than $20\%$. The ${\alpha}$-glucosidase inhibitor from culture filtrate of this strain was separated from the ${\beta}$-glucosidase inhibitor through Sephadex G-100 column chromatography.

• 한국미생물·생명공학회지
• /
• 제24권4호
• /
• pp.427-429
• /
• 1996

We have already cloned an extracellular $\alpha$-glucosidase gene from Aspergillus niger with oligonucleotide probe synthesized on the basis of the peptide sequences determined previously. The DNA sequence revealed an open reading frame of 895 amino acids split by three introns. We are attempting to construct an A. niger strain deficient in the $\alpha$-glucosidase enzyme activity, which would be useful for the glucoamylase production without contamination by the industrially undesirable $\alpha$-glucosidase. For destruction of the $\alpha$-glucosidase gene, we try to make transformations. A cloned partial $\alpha$-glucosidase gene was introduced into Aspergillus niger, and transformants with suppressed $\alpha$-glucosidase activity were isolated. The transformants were cultured on YPD medium which contained Hygromycin B at 30$\circ$C. The activity of $\alpha$-glucosidase of the suppressed transformants was compared to that of wild type activity. As shown by southern-hybridization, we detected that the transformant was a heterocaryon.

• 한국미생물·생명공학회지
• /
• 제39권1호
• /
• pp.49-55
• /
• 2011

토양으로부터 분리한 Streptomyces sp. 30여 균주들과 한국전통식품에서 분리한 Bacillus sp. 200여 균주들로부터 ${\alpha}$-glucosidase 의 활성을 저해하고 동시에 DNJ를 생산하는 유용균주를 선발하였다. 실험결과 한국전통식품인 청국장으로부터 ${\alpha}$-glucosidase 저해능이 높고 DNJ 생산능이 우수한 한개의 균주를 선발하였다. 이 균주의 동정을 위하여 API kit에 의한 균의 당 이용능 분석, HPLC와 GC에 의한 균체의 quinone 및 지방산 분석 등과 함께 균의 16S rDNA 염기서열을 분석하였으며 주사전자현미경에 의해 균주의 형태적 특성을 관찰하였다. 그 결과 본 연구를 통해 선발한 균주는 건강기능성식품 개발 등에 적용할 수 있는 GRAS에 속하는 균주임을 확인하여 B. subtilis MORI로 명명하였다.

• Journal of Microbiology and Biotechnology
• /
• 제22권12호
• /
• pp.1714-1723
• /
• 2012

${\beta}$-Glucosidase is necessary for the bioconversion of glycosidic phytochemicals in food. Two Bifidobacterium strains (Bifidobacterium animalis subsp. lactis SH5 and B. animalis subsp. lactis RD68) with relatively high ${\beta}$-glucosidase activities were selected among 46 lactic acid bacteria. A ${\beta}$-glucosidase gene (bbg572) from B. lactis was shotgun cloned, fully sequenced, and analyzed for its transcription start site, structural gene, and deduced transcriptional terminator. The structural gene of bbg572 was 1,383 bp. Based on amino sequence similarities, bbg572 was assigned to family 1 of the glycosyl hydrolases. To overexpress bbg572 in Bifidobacterium, several bifidobacteria expression vectors were constructed by combining several promoters and a terminator sequence from different bifidobacteria. The maximum activity of recombinant Bbg572 was achieved when it was expressed under its own promoter and terminator. Its enzyme activity increased 31-fold compared with those of its parental strains. The optimal pH for Bbg572 was pH 6.0. Bbg572 was stable at $37-40^{\circ}C$. It hydrolyzed isoflavones, quercetins, and disaccharides with various ${\beta}$-glucoside linkages. Bbg572 also converted the ginsenosides Rb1 and Rb2. These results suggest that this new ${\beta}$-glucosidase-positive Bifidobacterium transformant can be utilized for the production of specific aglycone products.

• 생명과학회지
• /
• 제33권10호
• /
• pp.783-790
• /
• 2023

현대인들의 식습관 변화로 인해 대사성 질환의 발생률이 증가하고 있으며, 특히 당뇨병이 가장 큰 문제로 꼽힌다. 하지만 기존의 당뇨병 치료제는 부작용을 동반하고 있어서 예로부터 쓰이던 천연물을 통해 부작용이 적은 항당뇨 활성 물질을 찾고자 하였다. 따라서 본 실험에서는 항당뇨 및 항산화 활성이 있는 천연물을 탐색하기 위하여, DPPH free radical scavenging assay와 α-glucosidase 및 PTP1B inhibition assay를 이용하였다. 항당뇨 효능이 예상되는 12가지의 시료를 메탄올로 추출하고 항당뇨 활성 및 항산화 활성을 측정하였다. 그 중 항당뇨 활성이 우수한 느릅나무, 벌나무 가지, 연 씨앗, 홍화 씨앗 등의 4가지 시료를 대상으로 에틸아세테이트, 부탄올을 이용하여 활성물질을 용매추출하여 항당뇨 활성을 측정하였다. 그 결과, α-glucosidase와 PTP1B 저해활성이 우수한 홍화 씨앗의 에틸아세테이트 분획물(MG-11-E)을 선정하였다. MG-11-E를 대상으로 preparative thin layer chromatography를 수행한 결과, 분획물 #6에서 α-glucosidase 및 PTP1B에 대한 우수한 저해활성을 보였다. 50% 메탄올을 이동상으로 하여 TLC 분획물 #6을 high performance liquid chromatography하여 각각을 분획하고 항당뇨 활성을 측정한 결과, 단일 peak를 보인 RT 4분에서 항당뇨 활성이 확인되었다. 따라서 홍화 씨앗의 추출물의 항당뇨 효능을 나타내는 항당뇨 활성 성분은 PTP1B 보다 α-glucosidase에 대한 저해 활성이 더욱 강하게 나타나 PTP1B를 저해하는 천연물과 조합하여 사용함으로써 당뇨병에 대한 효과를 높일 수 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
• /
• 제25권2호
• /
• pp.174-177
• /
• 2015

A potent α-glucosidase inhibitor (compound I) was isolated from coffee brews by activity-based fractionation and identified as a β-carboline alkaloid norharman (9H-pyrido[3.4-b]indole) on the basis of mass spectroscopy and nuclear magnetic resonance spectra (¹H NMR, ¹³C NMR, and COSY). The norharman showed potent inhibition against α-glucosidase enzyme in a concentration-dependent manner, with an IC₅₀ value of 0.27 mM for maltase and 0.41 mM for sucrase. A Lineweaver-Burk plot revealed that norharman inhibited α-glucosidase enzyme uncompetitively, with a K_i value of 0.13 mM.

• Archives of Pharmacal Research
• /
• 제20권4호
• /
• pp.346-350
• /
• 1997

The synthesis of cis- and trans-1,6-dihydroxypyrrolizidine starting from trans-4-hydroxy-L-proline and their evaluation as glycosidase inhibitors are reported. The cis-isomer was found to be a potent inhibitor against .alpha.-glucosidase and showed weak inhibitory effect against other glycosidases. The trans-isomer exhibited weak inhibitions of b-glucosidase and amylo-glucosidase and poor inhibition of other glycosidases.

• 한국식품조리과학회지
• /
• 제17권3호
• /
• pp.211-217
• /
• 2001

1. 약선식품소재의 물추출물 중 pH 저하효과가 가장 큰 것은 B. breve를 배양하였을 경우 Citrus aurantium (진피), Liriipe platyphylla (맥문동), Platycodon grandiflorum (길경), Schizandra chinensis (오미자)였고, 사람의 장내균총을 배양했을 경우는 Angelica gigas (당귀), Hordeum vulgare (맥아), Liriipe platyphylla (맥문동), Platycodon grandiflorum (길경), schizandra chinensis (오미자) 등이었다. 2. 약선식품소재의 $\beta$-glucosidase 효소활성억제효과는 B. breve를 배양했을 경우 Citrus aurantium(진피), Eugenia caryophyllata (정향), Liriipe platyphylla (맥문동), Platycodon grandiflorum (길경), Schizandra chinensis (오미자)가 90%. 이상의 억제효과를 나타내었고 사람의 장내균총에 대해서는 Eugenia caryophyllata (정향), Liriipe platyphylla (맥문동)가 40% 이상의 억제효과를 나타내었다. 3. $\beta$-Glucuronidase 활성을 억제하는 것으로 나타난 약선식품소재는 사람의 장내균총에 대해서는 Cinnamomum cassia(계지), Gardenia jasminoides(치자), Platycodon grandiflorum (길경) 등이였다. 4. 길경으로부터 in vitro에서 유산균증식효과를 나타내는 compound B를 분리하였으며 이 화합물은 기기분석을 한 결과 sucrose임을 밝혀졌으며, 사람의 장내균총에 대한 효과를 측정한 결과 $\beta$-glucosidase활성은 크게 억제하지 못했지만 $\beta$-glucuronidase 및 tryptophnase활성은 각각 49%, 67%의 억제효과를 나타내었다. 또한 사람의 장내우세균인 B. breve를 증식시키는 효과가 있었다.