• 한국수산과학회지
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• 제53권6호
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• pp.851-860
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• 2020

Shrimp in seasoned soy sauce (S-SS) is a popular seafood product in Korea, but it could be potentially hazardous; thus, this study was conducted to investigate its safety. Commercial S-SS were collected and analyzed for pH, volatile basic nitrogen (VBN), hygenic indicator microorganisms (viable cell count, coliforms, and Escherichia coli), food poisoning bacteria (Staphylococcus aureus, Vibrio parahaemolyticus, and Listeria monocytogenes), preservatives (dehydroacetic acid, sorbic acid, benzoic acid, and its salt, parahydroxybenzoate), tar colorants, and sensory properties. Domestic and foreign standards were also investigated for S-SS. Commercial S-SS ranged from to 6.2-7.3 for pH, 13.7-39.1 mg/100 g for VBN, and 4.6-6.9 log CFU/g for viable cells. The coliforms and E. coli of commercial S-SS were from ND to 3.4 log CFU/g and negative, respectively. Food poisoning bacteria, preservatives, and tar colorants were not detected in commercial S-SS. Only the coliform count and presence of E. coli in commercial S-SS exceeded the set standards of vietnam, while all items were within domestic and foreign standards.

• 급식외식위생학회지
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• 제3권1호
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• pp.38-44
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• 2022

This study investigated the microbiological hazards in the manufacturing processes of Naengmyeon. Sanitary indicative bacteria, such as aerobic plate counts and coliforms as well as pathogenic bacteria, were examined from raw materials, manufacturing processes, working area, 17 utensils and equipment. The aerobic plate counts for raw materials and arrowroot starch estimated as 0.77±0.68~5.02±0.28 and 5.02±0.28 log CFU/g, respectively. Coliforms were detected from wheat flour, buckwheat flour, and potato starch. Staphylococcus aureus was detected to be 0.61±1.06 log CFU/g in wheat flour and 0.20±0.35 log CFU/g in buckwheat flour. During the manufacturing process, aerobic plate counts for kneading process were 4.54±0.34 log CFU/g. But after the press out and heat process, contamination of aerobic plate counts and coliforms decreased and remained at a low level until the release process. Aerobic plate counts before washing disinfection of screw were 3.28±0.62 log CFU/100 cm², the level of which was high in utensils and equipment that had contact with employees or water. These results represent not only an important indicator for the hygienic level but also a scientific basis for analyzing biological hazards, which lead to the introduction of HACCP for the production of safe and hygienic cold noodles processed by manufacturers.

• 한국식품위생안전성학회지
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• 제33권6호
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• pp.447-452
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• 2018

유해 미생물에 오염된 농업용수는 배추의 재배기간 동안 지속적인 식중독세균 오염의 주원인이 될 수 있다. 농업용수는 야생동물 및 가축의 분변에 의해 오염되고 있다. 따라서 본 연구는 야생동물의 출입이 농업용수의 미생물학적 안전성에 미치는 영향을 조사하기 위하여 수행하였다. 이를 위하여 산악지대에 위치한 배추 재배농가에 사용되는 농업용수의 상류에서부터 하류까지 시기별 위생지표세균 오염도와 수원 상류의 야생동물의 출입 빈도를 조사하였다. 배추를 재배하는 기간 동안 멧돼지, 고라니 등 총 37회의 야생동물들이 농업용수 수원 근처에서 관찰되었다. 농업용수의 위생지표세균을 조사한 결과, 3종의 위생지표세균 모두 사람의 출입이 없는 상류에서부터 검출되었으며 대장균군, 대장균, 장구균의 오염도는 각각 2.13~4.32 log MPN/100mL, 0.26~2.03 log MPN/100mL, 1.43~3.49 log MPN/100mL 수준이었다. 대장균군과 대장균의 오염수준은 배추 이식기 보다 수온이 낮은 수확기에 낮았으나 장구균은 시기별로 큰 차이가 없었다. 본 연구의 결과로 미루어 볼 때 농업용수의 오염은 야생동물의 출입과 관련이 있을 것으로 판단된다.

• 미생물학회지
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• 제49권4호
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• pp.424-428
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• 2013

레지오넬라균에 의한 자연환경의 수체 및 각종 시설 용수의 오염도를 조사하는데 적용할 수 있는 오염도 지표를 통상적으로 측정되는 수질항목 중에서 선정하려는 목적으로, 다양한 수체에 적용된 수질항목들이 레지오넬라균 오염도와 어느 정도 유의한 상관관계를 맺는 지에 관한 메타분석을 실시하였다. 환경부의 수질관리 지침에서 레지오넬라균 오염도의 위험지수로 사용되고 있는 대장균의 경우, 총대장균군 항목과 레지오넬라균 검출여부의 교차비(odds ratio; OR)로 분석하였는데, 교차비는 1.05(0.36-3.12, 95% CI)로, 오즈의 차이가 없을 확률이 0.92에 달하였다. 또한, 총대장균군 자료는 유의한 수준의 자료간 이질성을 보였으며(P=0.008), 무작위적인 자료간 이질성이 전체 교차비 변량의 63%를 차지하였다. 종속영양세균수(HPC)의 교차비가 2.72(2.04-3.63)로 1 보다 매우 유의하게 높았고(P<0.0001), 자료간 이질성이 없었다($Q_{df=8}$=12.7, P=0.12). 탁도와 염소농도, 철과 구리 이온의 농도 등이 레지오넬라균 검출여부와 함께 조사되는 통상적 수질항목이었으나, 자료수의 부족과 정량 자료의 통일성 부족으로 적절한 메타분석이 수행 될 수 없었다. 결론적으로, 분변균의 오염도 보다, 수중 레지오넬라균 서식지(아메바와 생물막)의 양을 표현하는 종속영양세균수가 레지오넬라균의 오염도 지표로 활용될 수 있을 것으로 사료되며, 실험 방법의 표준화와 경계값을 판단하는 후속 연구가 필요하다.

• 한국식품과학회지
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• 제34권2호
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• pp.311-318
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• 2002

Lactobacillus plantarum에 대해 항균활성을 지니는 유산균을 김치로부터 분리하였다. 이 균은 Leuconostoc mesenteroides으로 동정되었으며 Leuconostoc mesenteroides B7으로 명명하였다. Leuconostoc mesenteroides B7이 생산하는 박테리오신은(박테리오신 B7) pH 및 열 안정성이 뛰어나 pH $2.5{\sim}9.5$ 그리고 $4^{\circ}C{\sim}120^{\circ}C$ 열처리에서도 항균활성을 안정하게 유지하였다. 박테리오신 B7은 proteinase K, trypsin, ${\alpha}-chymotrypsin$, 그리고 protease 처리에 의해 항균활성이 실활되므로 peptide나 단백질로 이루진 구조임을 알 수 있었다. 정제된 박테리오신 B7은 Tricine-SDS-PAGE를 통하여 분자량이 약 3,500 dalton임을 확인하였다. Leuconostoc mesenteroides B7과 이에 감수성인 균주, Lb. plantarum KFRI 464 혹은 Lb. delbruekii KFRI 347와의 혼합배양에 의하여 박테리오신 B7 생산이 증가됨을 확인하였고, 이는 박테리오신 생산 유도물질이(inducing factor) 감수성균주내에 존재함을 시사한다. 감수성균주의 세포분획을 통하여 inducing factor는 감수성균주의 세포벽과 세포내에 존재함을 알았다. 이 inducing factor가 proteinase K처리로 박테리오신 유도활성을 상실함으로써 이는 단백질성물질임을 시사하였다.

• 한국토양비료학회지
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• 제47권2호
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• pp.107-112
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• 2014

Glomalin has been suggested as an enhancer for soil stability by promoting the aggregation. In this study, we examined the concentrations of glomalin and microbial characteristics in 25 controlled horticultural soils sampled from Gyeongnam Province. Total glomalin had a significant positive correlation with soil organic matter (p < 0.01), soil microbial biomass carbon (p < 0.05), and dehydrogenase activity (p < 0.05) in controlled horticultural soils. In addition, the total glomalin had a significant positive correlation with concentrations of total fatty acid methyl esters, Gram-negative and Gram-positive bacteria, fungi, and arbuscular mycorrhizal fungi in controlled horticultural soils (p < 0.001). In conclusion, the concentration of total glomalin could be an indicator of microbial biomass richness for sustainable agriculture in controlled horticultural soils.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.588-594
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• 1998

Lactic acid bacteria were isolated from Kimchi and screened for bacteriocin production. Strain SE1, identified as Lactobacillus curvatus sp., showed the strongest inhibitory activity against Lactobacillus delbrueckii subsp. delbrueckii. The bacteriocin was inactivated by amyloglucosidase, trypsin, or protease K treatment. However, it maintained its activity under heat treatment at $100^{\circ}C$ for 60 min. The production of the bacteriocin had a growth-related mode and decreased around the early-stationary phase. The optimum temperature for the growth of L. curvatus SE1 was $37^{\circ}C$; however, the optimum temperature for bacteriocin production was $30^{\circ}C$. The bacteriocin activity was decreased by treatment with methanol, butanol, acetone, or chloroform, however, it was not affected by treatment with ethanol, iso-propanol, or cyclohexane. The inhibitory activity of bacteriocin was stable over a wide range of pHs (2 to 11). The bacteriocin from L. curvatus SE1 killed the indicator strain by a bactericidal mode of action. The bacteriocin from L. curvatus SE1 was partially purified by ethanol precipitation and ion exchange chromatography. SDS-polyacrylamide gel electrophoresis was used to determine the molecular weight of the bacteriocin by the bacteriocin activity test. The apparent molecular mass of the bacteriocin produced by L. curvatus SE1 was about 14 kDa.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.503-508
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• 2004

The antimicrobial substance produced by Lactobacillus bulgaricus was inactivated by protease. It showed inhibitory activity against Staphylococcus aureus ATCC6538, Streptococcus agalactiae ATCC14364, some Gram-positive and Gram-negative bacteria, and characteristics of a bacteriocin. The optimal temperature and culture time for the production of bacteriocin were $30^{\circ}C$ and 10 h, respectively, in the culture of L. bulgaricus. The bacteriocin production started in the exponential phase and reached a maximum at the early stationary phase. Using Staph. aureus ATCC6538 and Strep. agalactiae ATCC14364, known as common bovine mastitis pathogens, as indicator strains for determination of the bacteriocin activity, the antimicrobial activity of the bacteriocin was found to be stable in acidic and neutral pH's (2- 7) even at lOOT, whereas it was lost at high pH (10- 11) and $100^{\circ}C$. The mode of action for the antimicrobial activity was bacteriocidal, and the molecular weight determined by SDS-PAGE and overlay method was 14 kDa.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.195-200
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• 2000

Bacillus cereus BS229 was identified as a bacteriocin producer with a bactericidal activity against Bacillus thuringiensis subsp. Thomsoni BR-40. Bacillus cereus BS229 and cerein BS229, named tentatively as the bacteriocin produced by Bacillus cereus BS229, showed a narrow spectrum of actibity against Gram-positive and Gram-negative bacteria, along with yeast and molds. Production of cerein BS229 in a 5-1 fermenter followed typical kinetics of primary metabolite synthesis. The antibacterial activity of cerein BS229 on sensitive indicator cells disappeared completely by ${\alpha}-chmotrypsin$ or proteinase K, which indicates its proteinaceous nature. Cerein BS229 seemed to be very stable throughout the pH range of 2.0 of 9.0 and it was relatively heat labile, despite the fact that bacteriocin activity was still detected after being boied for 30min. Cerein BS229 actibity has been changed with some of the organic solvents such as toluene, ethanol, and chloroform. Direct detection of cerein BS229 actibity on SDS-PAGE suggested that it had an apparent molecular mass of about 8.2 kDa.

• 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.