• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.692-699
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• 2003

The changes of physicochemical and microbiological states of Myeolchi-jeot, a Korean salted and fermented anchovy, were investigated during 20 days of storage at $4^{\circ}C,\;15^{\circ}C,\;and\;30^{\circ}C$. A total of 314 bacterial strains isolated from Myeolchi-jeot samples at different time intervals were identified, and their abilities to produce biogenic amines were determined by both decarboxylating agar media and HPLC analysis. The salinity and water activity of Myeolchi-jeot changed little, while the pH increased slightly over 20 days at the tested temperatures. A significant increase of total plate count was observed in the sample stored at $30^{\circ}C$. Staphylococcus spp. were dominant in Myeolchi-jeot, and its amine productivity was very weak. Bacillus spp. appeared increasingly with the progress of storage at all temperatures tested, and the increase was considerably dependent on the increase of storage temperature. Also, 58-73%, 83-90%, 81-90%, and 83-93% of Bacillus strains had the ability to produce histamine, tyramine, putrescine, and cadaverine, respectively. Therefore, the main amine producer in Myeolchi-jeot stored for a long period seems to be the genus Bacillus, especially B. licheniformis.

• 한국토양비료학회지
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• 제41권5호
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• pp.348-353
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• 2008

토양에서 인산가용화 미생물의 역할을 탐색하기 위해, 밭과 시설재배 토양에 서식하는 인산가용화 미생물의 특성을 조사하였다. 노지 밭 토양에 비해 시설재배지 토양에서 EC가 높았으며, 토양 pH, 유기물, 유효인산, 치환성 양이온 및 총 인도 시설재배지에서 비교적 높은 경향이었다. 인산가용화 세균의 수는 시설재배지 토양이 밭 토양보다 높았으나, 인산가용화 세균의 종류는 밭 토양에 많았다. 인산가용화 세균의 밀도와 인산가용화능 간에 정의 상관이 있었다. 밭 토양에서는 Bacillus, Cedecea, Brevibacillus, Paenibacillus Pseudomonas, Serratia속 등이 시설재배지 토양에서는 Bacillus, Cellulomonas 속 등의 인산가용화 세균이 분리되었다.

• Journal of Microbiology and Biotechnology
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• 제31권3호
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• pp.447-455
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• 2021

Strains of four Bacillus spp. were respectively inoculated into sterilized soybeans and the free amino acid profiles of the resulting cultures were analyzed to discern their metabolic traits. After 30 days of culture, B. licheniformis showed the highest production of serine, threonine, and glutamic acid; B. subtilis exhibited the highest production of alanine, asparagine, glycine, leucine, proline, tryptophan, and lysine. B. velezensis increased the γ-aminobutyric acid (GABA) concentration to >200% of that in the control samples. B. sonorensis produced a somewhat similar amino acid profile with B. licheniformis. Comparative genomic analysis of the four Bacillus strains and the genetic profiles of the produced free amino acids revealed that genes involved in glutamate and arginine metabolism were not common to the four strains. The genes gadA/B (encoding a glutamate decarboxylase), rocE (amino acid permease), and puuD (γ-glutamyl-γ-aminobutyrate hydrolase) determined GABA production, and their presence was species-specific. Taken together, B. licheniformis and B. velezensis were respectively shown to have high potential to increase concentrations of glutamic acid and GABA, while B. subtilis has the ability to increase essential amino acid concentrations in fermented soybean foods.

• 환경생물
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• 제25권4호
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• pp.336-341
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• 2007

2004년 9월, 11월 그리고 2005년 2월 총 3회에 걸쳐 제주 차귀도 연안해역 10개 정점 표층수와 저층수에서 종속영양세균의 개체수를 조사하였고, 또한 해당 해역 수질의 이화학적 특성을 조사하였다. 2004년 9월, 11월 그리고 2005년 2월에 종속영양세균의 수는 각각 표층수에서는 $3.5\times10^1\sim1.16\times10^3\;cfu\;mL^{-1}$, $0.4\times10^1\sim5.6\times10^1\;cfu\;mL^{-1}$, $0.4\times10^1\sim7.8\times10^1$ 그리고 저층수에서는 $4.5\times10^1\sim1.0\times10^3\;cfu\;mL^{-1}$, $1.2\times10^1\sim1.5\times10^2\;cfu\;mL^{-1}$, $0.4\times10^1\sim4.4\times10^1\;cfu\;mL^{-1}$가 검출 되었다. 또한 조사해역의 수온, pH, 염분 및 COD, DO, 총 인, 총 질소, 투명도 그리고 부유물질을 분석하여 보았는데 수온이 높은 2004년 9월에 그 수치가 조금 높았을 뿐 해역수질 환경기준에 있어 1등급에 만족하는 결과가 나타났다. 2004년 9월, 11월, 2005년 2월 각 정점별 표층수와 저층수에서 우점적으로 자란 colony를 순수 분리하여 16S rRNA 염기서열 분석을 통하여 종속영양세균의 우점종을 비롯한 종속영양세균 군집을 분석한 결과 표층수와 저층수에서 Vibrio spp.와 Pseudoalteromonas spp.가 우점종으로 나타났으며 그 외에 Psuedomonas spp, Bacillus spp., Alteromonas spp., Aeromonas spp., Psychrobacter spp., Flavobacterium spp.가 조사 되었다.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.305-309
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• 2002

Raw soybean sprouts were tested for contamination with the following bacteria which have potential for pathogenesis or food spoilage : Salmonella spp., Escherichia coli O157:H7, Yersinia enterocolitica, Vibrio parahae-molyticus, Aeromonas hydrophila, Plesidomonas shigeloides, Pseudomonas aeruginosa, Staphylococcus aureus, Lis-teria monocytogenes, Bacillus cereus, Clostridium perfringens, Campylobacter jejuni, Erwinia spp., and Fusarium spp. Three of the above strains were isolated from the sprouts, and identified by morphological and biochemical methods including an API kit and ATB automated identification system. The isolate cultured in Cereus selective agar, a selective medium, was a Gram-positive, rod shaped, anaerobic spore former. The biochemical and culture tests revealed the following characteristics: catalase-positive, no growth on Simmon's citrate, NO₂ production and requirement of arginine for growth; the ATB automated identification system gave 99.8 % agreement for the identification of Bacillus cereus to the species level. The isolate cultured in Macconkey agar selective medium was Gram-negative, rod shaped and a gas former; the ATB-system gave 99.9% agreement for the identification of Aeromonas hydrophila to the species level. The isolate found in Pseudomonas isolation agar was Gram-negative, rod shaped, cytochrome oxidase-positive, a reducer of nitrates to nitrogen, and pyocyanin producer; the ATB-system gave 99.9 % agreement for the identification of Pseudomonas aeruginosa to the species level. These results indicate that the three bacteria species present in the soybean sprouts were Bacillus cereus, Aero-monas hydrophila, and Pseudomonas aeruginosa. Salmonella spp., Escherichia coli O157:H7, and Yersinia enter-ocolitica, which are associated with serious disease in humans, were not isolated from soybean sprouts examined in this study.

• 한국식품조리과학회지
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• 제25권1호
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• pp.45-54
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• 2009

Contamination levels of aerobic colony counts, coliforms and pathogenic bacteria were tested in fried rice dishes to monitor quality for risk management. The prevalence of Bacillus cereus in dishes from 8 Chinese-style restaurants and 2 institutional foodservices was 10%, and the bacteria's contamination levels was 3.47 log CFU/g. Echerichia coli, Staphylococcus aureus, and Salmonella were not detected in any of the 10 samples. However, for their aerobic colony counts and numbers of isolated coliforms, the samples were 30% and 70% over the microbial criteria, respectively, for ready-to-eat foods presented in the Korean Food Code. This suggests that fried rice dishes, although cooked with oil at high temperature, require special care. For the prediction of the growth curve of B. cereus spp. in the fried rice samples, an experiment design of 3 storage temperatures ($7^{\circ}C$, $35^{\circ}C$, $57^{\circ}C$) x 5 storage times (0 h, 2 h, 4 h, 6 h, 24 h) was applied. The sample exposed to $35^{\circ}C$ showed no B. cereus spp. at 0 h; however, there was a tendency of slow growth (1.0 log CFU/g) after 4 hours of storage and then faster growth at 6 h (3.7 log CFU/g) and 12 h (4.7 log CFU/g), showing a growth rate of 0.56 log CFU/g/hr. These results indicate that fried rice, despite being heat-treated, can become heavily contaminated with B. cereus spp. when held over 2 hours at room temperature. However, the samples stored at $7^{\circ}C$ and $57^{\circ}C$ over 24 hours were not contaminated with B. cereus. Based on these results, management guidelines for controlling B. cereus are suggested.

• 생명과학회지
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• 제9권3호
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• pp.314-327
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• 1999

This study was investigated to isolate identify the total bacteria and fungi from the indoor air of work-place of the shoes, paint, stainless steel, and plastic industries. The number of bacterial colonies on the nutrient agar plates were calculated by the open petridish method for 30 minutes in indoor air of work-places at the autumn and winter. The isolated bacteria were identified by Gram stain and biochemical test using API Staph and API 20E kits. The isolated fungal colonies were identified by gross appearance of the giant colonies and microscopic examination of their spore and hyphal characteristics on the slide culture method. The minimum inhibitory concentration (MIC) of several antibiotics against isolated bacteria was determined by the microdilution method with Mueller-Hinton broth. The 70-400 colonies in autumn and 54-236 colonies in winter were isolated from the indoor air of work-places of several industry. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 46.3%, 19.8%, 17.3%, and 16.1%, respectively. In Gram positive cocci, the most strains were identified as Aerococcus spp, Micrococcus spp, and Staphylococcus spp. In Gram positive and negative bacilli, and Gram negative cocci were identified as Bacillus spp, Pseudomonas spp, and Neisseria spp, respectively. The frequently isolated fungi were Aspergillus spp, Penicillium spp and Rhizopus spp, respectively. The frequently isolated Aerococcus spp, Micrococcus spp, and Staphylococus spp were highly resistance against ampicillin, erythromycin, methicillin, and tetracycline. These results arouse our attention to microbiologic pollution in the indoor air of work-places of industries.

• Journal of Microbiology and Biotechnology
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• 제21권3호
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• pp.229-235
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• 2011

Antimicrobial peptides exhibit high levels of antimicrobial activity against a broad range of spoilage and pathogenic microorganisms. Compared with bacteriocins produced by lactic acid bacteria, antimicrobial peptides from the genus Bacillus have been relatively less recognized despite their broad antimicrobial spectra. These peptides can be classified into two different groups based on whether they are ribosomally (bacteriocins) or nonribosomally (polymyxins and iturins) synthesized. Because of their broad spectra and high activity, antimicrobial peptides from Bacillus spp. may have great potential for applications in the food, agricultural, and pharmaceutical industries to prevent or control spoilage and pathogenic microorganisms. In this review, we introduce ribosomally synthesized antimicrobial peptides, the lantibiotic bacteriocins produced by members of Bacillus. In addition, the biosynthesis, genetic organization, mode of action, and regulation of subtilin, a well-investigated lantibiotic from Bacillus subtilis, are discussed.

• 한국미생물·생명공학회지
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• 제32권2호
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• pp.117-122
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• 2004

DEAE-sephadex ion exchange column chromatography에 의해 Bacillus sp. 유래 $\beta$-mannanase 의정제를 수행하여 비활성 21.57 units/$m\ell$, 정제배율 95.33을 나타내었다. SDS-PAGE에 의한 단일밴드를 확인하였고, 분자량은 38.9 kDa으로 결정되었다. 정제효소에 의해 guar gum galactomannan을 가수분해하여 1차 activated carbon column chromatography 와 2차 Sephadex G-25 gel filtration에 의해 당가수분해물을 분리 회수하여 TLC 및 FACE 에 의해 주요 당가수분해물은 중합도 5와 7로 확인되었다. B. longum B. bifidum, B. infantis, B. adolescentis, B. animalis, and B. breve의 생육활성에 대한 중합도 5와 7의 영향을 검토하기 위하여 modified-MRS 배지상에 탄소원으로 중합도 5와 7을 대체하여 생육활성을 비교한 결과 B. longum 에서는 중합도 5 galactomannooligosaccharide를 탄소원으로 대체한 경우 Standard MRS와 배교하여 0.62배로 감소하였다. 또한 중합도 5의 올리고당이 중합도 7의 올리고당보다 생육활성에 크게 기여하는 것으로 나타났다.

• 한국환경농학회지
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• 제30권4호
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• pp.424-431
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• 2011

본 연구에서 우리는 광양만의 해수와 표층 퇴적물에서 TBTCl 내성세균의 개체수를 조사하였다. 광양만에서 TBTCl 내성세균의 개체수는 해수에서 $2.5{\times}10^3-3.8{\times}10^3$ cfu/mL 범위였으며, 표층 퇴적물에서 TBTCl 내성세균의 개체수는 $3.2{\times}10^5-9.1{\times}10^5$ cfu/g 범위였다. 광양만에서 TBTCl 내성세균의 종조성은 Vibrio spp. (19.2%)가 가장 높은 우점종으로 나타났고, Bacillus spp. (16.2%), Aeromonas spp. (15.2%), Pseudomonas spp. (13.1%), Klebsiella spp. (11.1%), Alteromonas spp. (9.1%), Pantoea spp. (6.1%), Proteus spp. (3.0%), Listeria spp. (2.0%), unidentified (5.0%)의 순으로 우점하였다. 또한 11개의 대표적인 TBTCl 내성균주는 여러 중금속들(Cd, Cu, Hg 및 Zn)에도 내성을 나타내었다. 이들 중에서 가장 강한 TBTCl 내성을 보이는 T7 균주를 선별하여, API 20NE등을 이용하여 본 균주의 형태학적, 생리학적 및 생화학적 특성들을 조사하였다. T7 균주는 16S rRNA gene 염기서열 분석에 의해 Pantoea 속으로 동정되어 Pantoea sp. T7으로 명명되었다. 또한 본 균주는 $500{\mu}M$의 TBTCl 농도에서도 60시간 배양 후에 정상 균주 성장의 50.7%까지 증식하였다. Pantoea sp. T7의 생물학적 TBTCl 분해활성은 GC-FPD 분석에 의해 측정되었는데, $100{\mu}M$의 TBTCl 농도에서 배양 40시간 후에 TBTCl 제거 효율은 62.7%로 나타났다.