• Journal of Microbiology and Biotechnology
• /
• 제10권2호
• /
• pp.187-194
• /
• 2000

An actinomycetes strain, T-2, which produces transglutaminase (EC 2.3.2.13), was isolated from soil and identified as belonging to the Actinomadura sp., based on taxonomc studies. The conditions for the transglutaminase production and its enzymatic properties were investigated. The optimum components for the transglutaminase production were 2% glucose, 1% polypeptone and soytone, and 0.1% MnCl2. The optimum pH and temperature of the enzyme reaction were pH 8.0 and $45^{\circ}C$, respectively. The enzyme was stable within the pH range of 5.0-9.0 and $30^{\circ}C-45^{\circ}C$. The novel enzyme required no calcium ions for its activity. This enzyme polymerized various proteins such as casien, soy protein, hemoglobin, egg white, gelatin, and soybean milk.

• Journal of Microbiology and Biotechnology
• /
• 제32권6호
• /
• pp.749-760
• /
• 2022

α-Galactosidase is a debranching enzyme widely used in the food, feed, paper, and pharmaceuticals industries and plays an important role in hemicellulose degradation. Here, T26, an aerobic bacterial strain with thermostable α-galactosidase activity, was isolated from laboratory-preserved lignocellulolytic microbial consortium TMC7, and identified as Parageobacillus thermoglucosidasius. The α-galactosidase, called T26GAL and derived from the T26 culture supernatant, exhibited a maximum enzyme activity of 0.4976 IU/ml when cultured at 60℃ and 180 rpm for 2 days. Bioinformatics analysis revealed that the α-galactosidase T26GAL belongs to the GH36 family. Subsequently, the pET-26 vector was used for the heterologous expression of the T26 α-galactosidase gene in Escherichia coli BL21 (DE3). The optimum pH for α-galactosidase T26GAL was determined to be 8.0, while the optimum temperature was 60℃. In addition, T26GAL demonstrated a remarkable thermostability with more than 93% enzyme activity, even at a high temperature of 90℃. Furthermore, Ca²⁺ and Mg²⁺ promoted the activity of T26GAL while Zn²⁺ and Cu²⁺ inhibited it. The substrate specificity studies revealed that T26GAL efficiently degraded raffinose, stachyose, and guar gum, but not locust bean gum. This study thus facilitated the discovery of an effective heat-resistant α-galactosidase with potent industrial application. Meanwhile, as part of our research on lignocellulose degradation by a microbial consortium, the present work provides an important basis for encouraging further investigation into this enzyme complex.

• 대한환경공학회지
• /
• 제39권5호
• /
• pp.265-276
• /
• 2017

폐광산은 방치된 광미 등으로 인하여 주변환경에 복합적인 중금속 오염을 야기한다. 이를 방지하기 위하여 국내에서는 1990년대 중반부터 석회석 등의 안정화제와 복토를 이용한 안정화 공법을 기반으로 토양개량사업이 시행 중이다. 복원된 토양의 상부에서는 작물의 재배로 인해 중금속이 고정된 안정화 층이 지화학적 변화를 겪게 되며 이에 따른 중금속의 용출 및 이동이 가능하므로 토양개량사업을 마친 토양에 대한 질 평가 등의 사후 관리는 반드시 필요하다. 토양의 질 평가를 하기 위해서는 이화학적 분석 또는 생물학적인 분석을 개별적으로 하기보다는 이들을 결합한 종합적인 분석이 필요하며 이를 통해 토양의 생태기능상태(ecological functional state)를 평가할 수 있다. 본 연구에서는 대상시료로 경상북도 봉화군 풍정 광산, 전라남도 광양시 점동 광산, 충청남도 서산시 서성 광산 인근 안정화 처리 토양과 안정화 처리가 되지 않은 오염, 비오염 토양을 선정하였다. 토양의 이화학적 성질인 pH, CEC, LOI와 중금속 농도를 측정하였고, 미생물 효소활성도와 비소환원유전자를 정량하였다. 다변량 통계분석을 바탕으로 모든 데이터를 분석하여 토양 생태기능상태를 평가하였다. 안정화 심도 토양과 상부복토, 하부오염토 간의 상관관계를 확인한 결과, 안정화 심도 토양에서 중금속의 농도가 높게 측정되었다. 그리고 풍정광산에서는 안정화 처리 심도 토양이 하부오염토와 유사한 특성을, 점동, 서성 광산에서는 안정화 심도 토양이 상부복토와 유사한 특성을 나타내었는데 이는 점동, 서성 광산 주변 상부복토의 생태기능상태가 좋지 않을 수 있음을 시사한다.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1995년도 춘계학술대회
• /
• pp.107-107
• /
• 1995

The purpose of this study was to observe the effects of the polysaccharide(G009) obtained from liquid cultured Ganoderma lucidum IY009 on the lipidperoxidation in rat liver microsome. It is well known that the polysaccharide of G. lucidum have the hepatoprotective activity, antitumor activity etc., which was thought to have the relationship to anti-lipidperoxidation. In order to the estimate the effects of anti-lipidperoxidation of the polysaccharide obtained from G. lucidum IY009, enzymatic and nonenzymatic reaction were performed, in vitro, in rat liver microsome. In enzymatic lipid peroxidation reaction by ADP/FeCl$_3$/NADPH and $CCl_4$/NADPH, G009(1mg/ml) inhibited 77.4%, 39.4%, respectively, and the nonenzymatic reaction strongly exhibited 97.4% inhibition. And also, in enzymatic and nonenzymatic inducers treated with G009, the formation of MDA was progressively greater decreased by raising G009 concentration. These results suggest that anti-lipidperoxidation by G009 treatment may be play an important part in liver protection action.

• 약학회지
• /
• 제45권3호
• /
• pp.245-250
• /
• 2001

Aminoacyl tRNA synthetases of bacteria are known as potential targets for new anti-microbial agents. To isolate new inhibitors of bacterial methionyl-tRNA synthetases from natural sources, a new target-oriented screening system using whole cells which are over-expressing a target enzyme was developed. Approximately 8,000 culture broths of microorganisms from soils were tested by this screening system. Among them, ten culture broths was found to contain inhibitory activity against methionyl -tRNA synthetases of Escherichia coli. For the validation of the screening system, this new method was compared with in vitro enzymatic method. Seven out of 10 culture broths showed inhibitory activity against methionyl-tRNA synthetases of E. coli. This result showed that the new screening system was comparable to the enzyme assay. Thus we believe that our screening system as a new method can be applied for the screening of new antibiotics inhibiting bacterial methionyl-tRNA synthetases from natural products.

• 한국환경농학회지
• /
• 제27권3호
• /
• pp.260-266
• /
• 2008

시설 유기농 포도 재배지에서 공중 질소 고정과 잡초 억제를 목적으로 도입할 수 있는 월동 녹비가 녹비 생육 초기인 봄에 토양 미생물 활성과 다양성에 미치는 효과를 검토하기 위하여 헤어리 베치,자운영,레드 클로버를 녹비로 파종한 후 효소 활성과 토양 미생물 군락의 기질 이용성 및 인지질 지방산 차이에 의한 토양 미생물 다양성을 조사하였다. 탈수소효소 활성과 FDA 수화도에 의한 미생물 활성으로 측정한 토양 미생물 활성은 처리간에 차이가 없었다. Biolog Ecoplate의 평균 색도 변화는 레드 클로버가 대조구에 비하여 높았다. Biolog EcoPlate에 의한 토양 미생물 군락의 기질 이용성은 자운영 처리구가 헤어리 베치구 및 레드 클로버 처리구와 뚜렷이 구분되었다. 그리고 미생물 군락의 기능적 다양성 지수는 헤어리 베치구가 대조구 보다 유의성 있게 높았다. 인지질 지방산 구성에 의한 미생물 군락의 차이를 주요인 분석으로 분석한 결과 자운영이 대조구와 현저히 구분되었고 녹비 처리구 간에는 차이가 없었다.

• Journal of Microbiology and Biotechnology
• /
• 제23권5호
• /
• pp.644-651
• /
• 2013

The fermented manure derivative known as Preparation 500 is traditionally used as a field spray in biodynamic agriculture for maintaining and increasing soil fertility. This work aimed at characterizing the product from a microbiological standpoint and at assaying its bioactive properties. The approach involved molecular taxonomical characterization of the culturable microbial community; ARISA fingerprints of the total bacteria and fungal communities; chemical elemental macronutrient analysis via a combustion analyzer; activity assays for six key enzymes; bioassays for bacterial quorum sensing and chitolipooligosaccharide production; and plant hormone-like activity. The material was found to harbor a bacterial community of $2.38{\times}10^8$ CFU/g dw dominated by Gram-positives with minor instances of Actinobacteria and Gammaproteobacteria. ARISA showed a coherence of bacterial assemblages in different preparation lots of the same year in spite of geographic origin. Enzymatic activities showed elevated values of ${\beta}$-glucosidase, alkaline phosphatase, chitinase, and esterase. The preparation had no quorum sensing-detectable signal, and no rhizobial nod gene-inducing properties, but displayed a strong auxin-like effect on plants. Enzymatic analyses indicated a bioactive potential in the fertility and nutrient cycling contexts. The IAA activity and microbial degradation products qualify for a possible activity as soil biostimulants. Quantitative details and possible modes of action are discussed.

• Journal of Microbiology and Biotechnology
• /
• 제30권7호
• /
• pp.1082-1091
• /
• 2020

Microbial transglutaminases (MTGs) are widely used in the food industry. In this study, the MTG gene of Streptomyces sp. TYQ1024 was cloned and expressed in a food-grade bacterial strain, Bacillus subtilis SCK6. Extracellular activity of the MTG after codon and signal peptide (SP Ync M) optimization was 20 times that of the pre-optimized enzyme. After purification, the molecular weight of the MTG was 38 kDa and the specific activity was 63.75 U/mg. The optimal temperature and pH for the recombinant MTG activity were 50℃ and 8.0, respectively. MTG activity increased 1.42-fold in the presence of β-ME and 1.6-fold in the presence of DTT. Moreover, 18% sodium chloride still resulted in 83% enzyme activity, which showed good salt tolerance. Cross-linking gelatin with the MTG increased the strength of gelatin 1.67 times and increased the thermal denaturation temperature from 61.8 to 75.8℃. The MTG also significantly increased the strength and thermal stability of gelatin. These characteristics demonstrated the huge commercial potential of MTG, such as for applications in salted protein foods.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권10호
• /
• pp.1590-1598
• /
• 2020

Objective: The objective of this study was to evaluate the effects of lysophospholipids (LPL) supplementation on rumen fermentation, degradability, and microbial diversity in forage with high oil diet in an in vitro system. Methods: Four experimental treatments were used: i) annual ryegrass (CON), ii) 93% annual ryegrass +7% corn oil on a dry matter (DM) basis (OiL), iii) OiL with a low level (0.08% of dietary DM) of LPL (LLPL), and iv) OiL with a high level (0.16% of dietary DM) of LPL (HLPL). An in vitro fermentation experiment was performed using strained rumen fluid for 48 h incubations. In vitro DM degradability (IVDMD), in vitro neutral detergent fiber degradability, pH, ammonia nitrogen (NH₃-N), volatile fatty acid (VFA), and microbial diversity were estimated. Results: There was no significant change in IVDMD, pH, NH₃-N, and total VFA production among treatments. The LPL supplementation significantly increased the proportion of butyrate and valerate (Linear effect [Lin], p = 0.004 and <0.001, respectively). The LPL supplementation tended to increase the total bacteria in a linear manner (p = 0.089). There were significant decreases in the relative proportions of cellulolytic (Fibrobacter succinogenes and Ruminococcus albus) and lipolytic (Anaerovibrio lipolytica and Butyrivibrio proteoclasticus) bacteria with increasing levels of LPL supplementation (Lin, p = 0.028, 0.006, 0.003, and 0.003, respectively). Conclusion: The LPL supplementation had antimicrobial effects on several cellulolytic and lipolytic bacteria, with no significant difference in nutrient degradability (DM and neutral detergent fiber) and general bacterial counts, suggesting that LPL supplementation might increase the enzymatic activity of rumen bacteria. Therefore, LPL supplementation may be more effective as an antimicrobial agent rather than as an emulsifier in the rumen.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.563-566
• /
• 2000

키토산으로부터 키토산 올리고당을 생산하기 위한 유용 효소원을 개발하기 위해서 토양에서 4종의 미생물을 분리하였으며, 가장 높은 활성의 chitosanase를 생산하는 Bacillus sp. HSB-21 균주를 선정하였다. 분리균주로부터 생산된 chitosanase는 endo-type의 효소로 분자량이 약 21,000이었다. 최적 pH와 온도는 각각 5.5, $50^{\circ}C$이었으며, pH $3{\sim}8$ 범위와 $40^{\circ}C$까지 비교적 안정한 효소로 나타났다. 본 효소는 키토산을 분해하여 단당을 형성하지 않았으며 주로 $2{\sim}8$당을 포함하는 키토산 올리고당을 만들었다. 그러므로 본 효소는 고중합도 키토산 올리고당의 생산을 위한 응용 가능성이 큰 것으로 판단된다.