• 생명과학회지
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• 제19권6호
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• pp.787-792
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• 2009

제주도 양식장 배출수 퇴적층에서 단백질 분해 효소를 생산하는 세균을 분리하였으며, 각각 SK-2, 및 SK-125라고 명명하였다. 분리균주 SK-2의 16S rDNA의 염기서열 분석 결과 Baeillus lieheniformis와 Baeillus subtillis의 염기서열과 99%의 상동성을 보였으며, BIOLOG를 이용한 생화학적 분석에서도 Bacillus family와 유사한 특성을 보여 최종적으로 분리균주 SK-2를 Baeillus sp. SK-2으로 명명하였다. 또한 분리균주 SK-125의 16S rDNA의 염기서열 분석 결과 Pseudoal teromonas haloplanktis의 염기서열과 99% 의 상동성을 보였으며, BIOLOG를 이용한 생화학적 분석에서도 Pseudoalteromonas family와 유사한 특성을 보여 최종적으로 분리균주 SK-125를 Pseudoalteromonas sp. SK-125라고 명명하였다. Baeillus sp. SK-2와 Pseudoalteromonas sp. SK-125균주의 온도별 실험에서는 $40^{\circ}C$에서 가장 높은 생육도를 보였으며, 효소활성은 Bacillus sp. SK-2와 Pseudoalteromonas sp. SK-125 두 균주 모두 $30^{\circ}C$에서 가장 높은 활성을 보였다.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.80-85
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• 1999

To develop bioflocculant for wastewater treatment, about 60 type culture strains and 450 strains isolated from natural sources were examined for screening their ability to flocculate the swine wastewater. Among them, YWO-5 showed the highest activity for NTU removal efficiency and was identified as Bacillus megaterium according to the cultural, morphological and physiological properties. The maximum production of the flocculant was achieved in culture medium containing 2% glucose, 0.05% soytone, 0.01% $CaCl_2$, 0.05% $KH_2PO_4$, and 0.05% yeast extract with initial pH 6.5 when cultured with rotary shaker controlled at 20$^{\circ}C$ and 150 rpm. With jar fermentor, the maximum production was reached to NTU removal efficiency of 93% after 3 days under the optimal conditions. The bioflocculant produced by Bacillus megaterium YWO-5 was effective on various suspended solids and organic wastewaters.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1018-1023
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• 2007

Bacillus subtilis CH3-5 was isolated from cheonggukjang prepared according to traditional methods. CH3-5 secreted at least four different fibrinolytic proteases (63, 47, 29, and 20 kDa) into the culture medium. A fibrinolytic enzyme gene, aprE2, encoding a 29kDa enzyme was cloned from the genomic DNA of CH3-5, and the DNA sequence determined. aprE2 was overexpressed in heterologous B. subtilis strains deficient in extracellular proteases using a E. coli-Bacillus shuttle vector. A 29 kDa AprE2 band was observed and AprE2 seemed to exhibit higher activities towards fibrin rather than casein.

• Preventive Nutrition and Food Science
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• 제9권1호
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• pp.14-20
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• 2004

Bacillus strains capable of producing fibrinolytic enzyme were isolated from traditional fermented Korean soybean paste and Japanese fermented soybean (Natto). Among the 16 strains, a selected Bacillus sp. was identified as bacillus firmus, with 80.7％ homology, by API kit analysis. Seed starter or B. firmus NA-1 was prepared with 5％ soymilk prepared from micronized soybean powder. To produce fibrinolytic enzyme by B. firmus NA-1 the liquid culture was performed with NB broth (pH 7.0) fortified with 1％ galactose, 0.1% tryptone, and 0.5% $K_2$HPO$_4$, by shaking with 180 rpm at 37$^{\circ}C$. Fibrinolytic enzyme activity reached the highest value at 7.8 unit/mL (plasmin unit) after fermentation for 72 hr. The crude fibrinolytic enzyme showed higher relative activity in the range of pH 7.0∼9.0. The activity of crude fibrinolytic enzyme was well maintained even after concentration by the vacuum evaporation at 5$0^{\circ}C$ for 1 hr.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1836-1840
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• 2008

Bacteriocins are antimicrobial peptides that are produced by bacteria and toxic to bacterial strains closely related to the producer strain. It has previously been reported that Bacillus thuringiensis strain NEB17 and Bacillus thuringiensis subsp. kurstaki BUPM4 produce the bacteriocins thuricin 17 (3,162 Da) and bacthuricin F4 (3,160.05 Da), respectively. Here, we demonstrate that these bacteriocins have functional similarities and show a similar spectrum of antimicrobial activities against indicator strains. We also studied the effects of sterilization methods on the recovery and biological activities of these bacteriocins. They were completely degraded by autoclaving and the two were similarly affected by the tested filter membranes. Polyvinylidene fluoride (PVDF), polyestersulfone (PES), and cellulose acetate (CA) are suitable for filter sterilization of these bacteriocins. The two bacteriocins were stable across a range of storage conditions. These data will facilitate their utilization in food preservation or agricultural applications.

• Journal of Microbiology
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• 제41권3호
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• pp.196-201
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• 2003

The object of this study was to characterize Bacillus strains GB-017 and GB-0356, which produce antifungal substances, especially for plant pathogens. In addition, this study was undertaken to characterize the culture conditions required for the production of antifungal substances and to document some of the properties of the antifungal substance produced by these soil-isolated strains. Strains GB-0365 and GB-017 were found to be bacillus-shaped, gram-positive and motile, and to inhibit Botrytis cineria, Fusarium sp., Pythium sp., and Rhizoctonia solani. Antagonistic activity was maintained up to pH 9.0, and the antifungal activity was stable to heat at 80$^{\circ}C$ for 1 h. Antifungal substances were separated and purified using ion exchange and adsorption columns including WK-I0(H$\^$＋) (pH 7.0), HP20 column (pH 3.0) and IPA (pH 3.0). and IPA. Its UV absorption spectrum showed major peaks at 231 and 259 nm, corresponding to polyene and lactone. A fast atom bombardment mass spectrum (FAB MS) showed a highest peak at 441 m/z and major peaks at 192, 205, and 370 m/z.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.498-508
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• 2019

Bacillus species were isolated from iru, a traditional fermented condiment in Nigeria. Polyphasic approach was used to evaluate the phylogenetic relationship and strain sub-type of the isolated species. Additionally, the phylogenetic profiles of the species isolated from iru were compared with those of bacilli isolated from different continents. The phylogenetic diversity analysis was performed using the combination of 16S rRNA gene sequencing, ITS-PCR, ITS-PCR-RFLP, and M13 RAPD-PCR. The analysis revealed that Bacillus subtilis U170B and B. subtilis U146A isolated from iru were the closest relatives of strains belonging to the phylogeny of B. subtilis sensu stricto and were related to other bacilli isolated from different continents that had functional benefits. The two isolated species exhibited resistance to acidic pH (pH 2.0). The survival rates of B. subtilis U170B, B. subtilis U146A, and B. clausii UBBC-07 (commercial probiotic strain) cultured at pH 2.0 for 3 h were 33.45, 12.44, and 9.53%, respectively. The strains were highly tolerant to bile salts [0.3% (w/v)]. B. subtilis U170B exhibited the highest cell viability (43.45%) when cultured for 3 h in the presence of bile salts, followed by B. subtilis U146A (25%) and B. clausii UBBC-07 (18.94%). B. subtilis U170B and B. subtilis U146A did not exhibit haemolytic activity and were susceptible to different antibiotics. Additionally, these two strains exhibited weak antagonistic activity against B. cereus. The diverse wild strains of B. subtilis can be used as a safe multifunctional starter culture for the industrial production of condiments with health benefits.

• Applied Biological Chemistry
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• 제41권3호
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• pp.213-218
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• 1998

전통 대두발효식품으로부터 색소 생성능과 protease 활성이 가장 강한 균을 선별하여 Bacillus sp. CS-l7로 동정하였다. CS-17 균의 균체증식은 배양 24시간, protease 활성은 배양 48시간, 그리고 색소 생성은 배양 72시간 후 최대에 달하였다. Bacillus sp. CS-17은 대두분말을 1.0% 첨가한 색소 생성용 기본배지에서 가장 높은 색소 생성능을 가지는 것으로 나타났다. 배양조건이 Bacillus sp. CS-17의 색소 생성에 미치는 효과를 조사한 결과, pH 8.5에서 $37^{\circ}C$, 72시간 배양하였을 때 최적의 색소 생성을 보였다. NaCl의 첨가는 색소 생성능을 억제하는 것으로 나타났다. 이상의 결과로 Bacillus sp. CS-17의 색소 생성 최적조건은 $37^{\circ}C$, pH 8.5에서 72시간동안 배양하였을 때로 추정되었다. 그람 양성균 5주 및 그람 음성균 6주에 대하여 색소 농축액의 항균활성을 paper disc법으로 조사한 결과, B. subtilis, P. aeruginosa, S. typhimurium, E. aerogenes, B. cereus, A. hydrophila의 성장에 대한 항균효과가 인정되었으나 그 활성은 전반적으로 미약하였다.

• 한국식품과학회지
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• 제28권1호
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• pp.66-71
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• 1996

쌀밥의 저장성을 향상시킬 목적으로 쌀밥 부패 미생물을 분리, 동정하고 이들과 표준 균주에 대한 녹차 물추출물의 항균활성을 측정하였다. 표준균주 Bacillus subtilis ATCC 6633, Salmonella typhimurium ATCC 14028, Bacillus cereus YUFE 2004 및 Staphylococcus aureus YUFE 2087 모두 녹차 물추출물이 500, 1000 ppm 첨가된 broth system에서 생육이 억제되었다. 쌀밥 부패에 관여하는 주요 미생물은 두 균주 모두에서 형태적, 생리적 특성과 API 50 CHB kit 그리고 균체 지방산 분석을 통해 Bacillus subtilis로 동정되었다. 분리, 동정된 균주 중 Bacillus subtilis RHJ-I의 생육은 녹차 물추출물이 500, 1000 ppm 첨가된 broth system에서 그 생육이 억제되었다.

• 미생물학회지
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• 제54권4호
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• pp.428-435
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• 2018

본 연구는 담수환경에서 항균활성을 보유한 미생물을 발굴하고, 활성 증진을 위해 배양조건을 최적화하는 것이다. 상주시 중동면 오상저수지에서 시료를 채취하여 38종의 미생물을 순수분리하였다. 16S rRNA 염기서열 분석에 근거하여 Proteobacteria강(22종), Actinobacteria강(7종), Bacteroidetes강(6종), Firmicutes강(3종)으로 구성되어있는 것을 확인하였다. 메티실린내성 황색포도상구군 등 10종의 유해미생물에 대한 항균활성을 보유한 Burkholderia sp. OS17 균주를 선발하였다. 항균활성 증진을 위한 상용배지, 온도, 초기 pH별 생육 및 항균활성 비교실험을 수행하였다. OS17 균주는 YPD 배지, $35^{\circ}C$, pH 6.5로 배양했을 때 가장 활성이 높았다. LB, NB, TSB, R2A 배지와 $20^{\circ}C$, $25^{\circ}C$ 배양했을 때는 생장은 가능하나 항균활성이 전혀 없었다. 이전결과를 바탕으로 YPD 배지, $35^{\circ}C$에서 배양하면서 5 L fermenter를 이용하여 생육, 항균활성, pH 확인을 통해 배양 48시간을 최적 배양시간으로 선정하였다. 항균활성을 보유한 미생물의 배양 최적화는 항균물질 생산에 영향을 미치고, 이는 상업적 응용에 이점으로 작용할 수 있다.