• 생명과학회지
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• 제14권1호
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• pp.193-197
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• 2004

A continuous enrichment culture procedure was used to isolate bacteria from various soil sources capable of suppressing large patch disease of turfgrass. Six isolates consistently suppressed large patch in turfgrass, and ranged in the spectrum of extracellular enzymes that they expressed. The best disease- suppressing isolate, TBM912, expressed protease, CMCase, and pectinase activity and inhibited the growth of Rhizectonin solani and Betrytis cinerea in vitro. Here we show that this strain also produces an antibiotic that was identified by TLC, SDS-PACE and HPLC analysis as lipopeptide.

• 한국미생물·생명공학회지
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• 제42권2호
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• pp.99-105
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• 2014

가정에서 제조된 된장을 산성조건에서 계대 배양한 후 균체외 mannanase 를 생산하는 Bacillus sp. YB-1401를 분리하였다. 분리균의 당이용능을 비롯한 생화학적 특성은 Brevibacillus laterosporus와 유사도(61.1%)가 가장 높은 반면에 16S rRNA 유전자의 염기서열은 B. amyloliquefaciens와 유사도가 가장 높았다. 분리균 YB-1401의 mannanase 생산성은 mannans에 의해 급격하게 증가하였으며, 특히 곤약(4%)이 첨가된 배지에서 약 265 U/ml로 최대 생산성을 보였다. 분리균의 mannanase는 $55^{\circ}C$와 pH 5.5 반응조건에서 최대활성을 보였으며 pH 3.5-11.0의 범위에서 1시간 방치하였을 때 실활이 거의 일어나지 않았다. 또한 LBG와 guar gum 및 mannooligosaccharides를 mannanase로 분해하였을 때 주된 반응산물로 mannobiose와 mannotriose가 생성되었으며 mannose도 소량 생성되었다.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.439-444
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• 1996

A bacterial strain, designated as WY22, producing extracellular chitinase was isolated from the soil around the Youngduck area, after enrichment culture in a medium containing $1{\%}$ (w/v) wet colloidal chitin as a sole carbon source. The isolate was identified as a strain of Bacillus sp. based on its morphological and physiological characteristics. It was observed that Bacillus sp. WY22 could inhibit the growth of Fusarium oxysporum with hyphal extention-inhibition assay on potato dextrose agar plate supplemented with $1{\%}$ collidal chitin. Optimum culture conditions of Bacillus sp. WY22 were examined for chitinase production in a chitin medium. High level production of chitinase was observed not only in the chitin medium but in a medium supplemented with $1{\%}$ N-glucosamine or lactose instead of chitin. The optimum concentrations of colloidal chitin and yeast extract were 3.0 and $0.5{\%}$, and the optimum culture conditions for initial pH of medium and temperature were 7.0 and $30^{\circ}C$, respectively, for the production of chitinase.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.329-333
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• 2000

Alkaline bacterium producing a high pro-tease activity at low temperature was isolated by using enrichment culture from soil samples and identified as Bacil-lus sp. WRD-1 Cell growth was maximal at 10 hours and the optimal initial pH and culture time of culture condition for enzyme production was pH 7 and 10 hours, respectively. Temperature range of high enzyme activity were $10~40^{\circ}C$. The optimal pH and temperature for the enzyme activity were pH9 and $30^{\circ}C$.

• 한국환경보건학회지
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• 제24권3호
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• pp.54-62
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• 1998

20 bacterial strains capable of growing on phenol minimal medium were isolated from soil and wastewater by the enrichment culture technique, and among them, one isolate which was the best in the cell growth was selected and identified as Bacillus sp. SH3 by its characteristics. Strain SH3 could grow with phenol as the sole carbon source up to 15 mM, but did not grow in minimal medium containing above 20 mM of phenol. The optimal conditions of temperature and initial pH for growth and phenol degradation were 30$^{\circ}$C and 7.5, respectively. This strain could grow on various aromatic compounds such as catechol, protocatechuic acid, gentisic acid, o-, m-, p-cresol, benzoic acid, p-hydroxybenzoic acid, anthranilic acid, phenyl acetate and pentachlorophenol, and the growth-limiting log P value of strain SH3 on organic solvents was 3.1. In batch culture, strain SH3 degraded 97% of 10 mM phenol in 48 hours. In continuous culture under the conditions of 20 mM of influent phenol concentration and 0.050 hr$^{-1}$ of dilution rate, the treatment rate of phenol was 94%.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1617-1626
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• 2013

The Bacterial community structure and its complexity of the enrichment culture during the isolation and screening of imidacloprid-degrading strain were studied using denaturating gradient gel electrophoresis analysis. The dominant bacteria in the original tea rhizosphere soil were uncultured bacteria, Rhizobium sp., Sinorhizobium, Ochrobactrum sp., Alcaligenes, Bacillus sp., Bacterium, Klebsiella sp., and Ensifer adhaerens. The bacterial community structure was altered extensively and its complexity reduced during the enrichment process, and four culturable bacteria, Ochrobactrum sp., Rhizobium sp., Geobacillus stearothermophilus, and Alcaligenes faecalis, remained in the final enrichment. Only one indigenous strain, BCL-1, with imidacloprid-degrading potential, was isolated from the sixth enrichment culture. This isolate was a gram-negative rod-shaped bacterium and identified as the genus Ochrobactrum based on its morphological, physiological, and biochemical properties and its 16S rRNA gene sequence. The degradation test showed that approximately 67.67% of the imidacloprid (50 mg/l) was degraded within 48 h by strain BCL-1. The optimum conditions for degradation were a pH of 8 and $30^{\circ}C$. The simulation of imidacloprid bioremediation by strain BCL-1 in soil demonstrated that the best performance in situ (tea soil) resulted in the degradation of 92.44% of the imidacloprid (100 mg/g) within 20 days, which was better than those observed in the ex situ simulations that were 64.66% (cabbage soil), 41.15% (potato soil), and 54.15% (tomato soil).

• Applied Biological Chemistry
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• 제44권4호
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• pp.246-250
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• 2001

토양시료로부터 높은 활성의 pretense를 생산하는 세균을 수십종 분리하였다. 분리된 세균중에서 protease활성과 성장속도면에서 가장 우수한 균주를 선별하여 WRD-2로 명명하였으며, 형태학적, 생화학적 및 생리학적 특성을 조사한 후 Bacillus sp로 동정되었다. WRD-2조효소액의 protease 최적 활성은 pH 6.0, 온도는 $40^{\circ}C$로 중성 protease임을 알 수 있었고, 온도 $20{\sim}40^{\circ}C$에서 높은 protease활성을 나타내었다. 또한, 초기 pH에 따른 protease 활성에서는 pH 6에서 가장 높은 활성을 나타내었고, 배양배지의 영향은 탄소원으로 maltose 3%, 질소원으로 yeast extract 4%에서 가장 높은 pretense활성을 나타내었다.

• 한국환경농학회지
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• 제27권3호
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• pp.292-297
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• 2008

우리나라에서 유일하게 사용되고 있는 유기염소계 살충제 endosulfan을 미생물학적 방법으로 분해하기 위하여 총 182점의 토양, 퇴비 및 액상의 미생물 시료를 접종원으로 실시한 endosulfan 집식(enrichment) 실험으로부터 endosulfan을 endosulfan diol 형태로 경유하여 분해하는 균주를 선발하고 그 이름을 Bacillus sp. E64-2로 명명하였다. 분리균주는 7일만에 배지에 함유된 10 mg/L 농도의 endosulfan을 99% 이상 분해하였다. 또한 분리균주 Bacillus sp. E64-2의 조효소액은 endosulfan을 endosulfan diol로 전환하는 활성을 가지고 있었으며 균주 자체는 생육 중에 배지의 pH를 배양 7일 만에 pH 7.0에서 pH 8.4로 올릴 수 있었다. 이러한 효소활성과 pH 증가 능력은 분리균주 E64-2에 의한 endosulfan 분해의 주된 작용 인자인 것으로 판단되며 이 균주는 효소에 의한 분해작용과 pH 상승작용을 통하여 토양에 잔류는 난분해성 물질인 endosulfan을 bioremediation하기 위한 연구의 기초 균주로서의 가치가있을 것으로 판단된다.

• 환경위생공학
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• 제13권2호
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• pp.34-39
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• 1998

For more convenient and rapidly isolation of Bacillus thuringiensis subsp. israelensis(Bti), 1) heat treatment spore forming bacteria, 2) growth in enrichment culture media for Bacillus sp. and 3) selection of bacteria producing a lecithinase for Bacillus thuringiensis subsp. israelensis, were performed. Spore forming bacteria were counted 4.8 $\times $ 10$^{8}$cells/g soil on NAPGCY media, 9.2 $\times $ 10$^{7}$cells/g soil on NA media, and 3.6 $\times $ 10$^{8}$cells/g soil on NAAC media, respectively. Bacteria producing only a lecithinase were reached at 25.2% on medium contained egg york, bacteria only producing a delta-endotoxin were reached at 23.2% by phase contrast microscope, and bacteria producing a lecithinase & a delta-endotoxin simultaneously were reached at 13.7%. Bacillus thuringiensis which producing a lecithinase and a delta-endotoxin simultaneously among bacteria producing a lecithinase, were reached at 56.5%; A half of Bacillus thuringiensis was produced a delta-endotoxin, but not produced a lecithinase. Among 8 isolates of Bacillus thuringiensis, two strain of Bti which has a mosquito-cidal toxin, were detected by PCR using a specific primer of $\delta $-endotoxin gene from Bti.

• 생명과학회지
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• 제21권4호
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• pp.554-560
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• 2011

제지폐수의 효율적인 생물학적 처리와 폐수특성에 적합한 미생물제제의 개발을 위하여 토양 및 산업폐수로부터 방향족 화합물에 분해활성이 높은 KN11, KN13 및 KN27 균주와 세포 외 섬유소 가수분해효소 생산 균주 GT21 등의 균주를 분리하였다. 형태학적, 생리학적 및 생화학적 분류를 통해 이들 분리주 KN11, KN13, KN27 및 GT21 등은 Acinetobacter sp., Neisseria sp., Bacillus sp., Pseudomonas sp.와 유사한 것으로 판명되어 최종적으로 각각 Acinetobacter sp. KN11, Neisseria sp. KN13, Bacillus sp. KN27, Pseudomonas sp. GT21로 명명하였다. 제지폐수 중 난분해성 물질과 COD 증가원인 물질을 분석하고자 GC/MS를 이용하여 방향족 화합물 및 그 유도체들을 검출하였다. 분리균주 Acinetobacter sp. KN11, Neisseria sp. KN13, Bacillus sp. KN27 및 Pseudomonas sp. GT21의 균체로 구성된 미생물제제 J30을 제조하여 제지폐수의 효율적 처리를 위한 연구에 사용하였다. 미생물제제 J30의 제지폐수에서 COD 제거를 위한 최적온도와 pH는 각각 $30^{\circ}C$와 7.5였으며 배양 60시간에서 최대의 COD 제거효율을 나타내었다. 실험실 규모의 pilot plant에서 미생물제제 J30의 COD 제거효율은 87%의 높은 제거효율을 나타내었다.