• 한국환경보건학회지
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• 제39권5호
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• pp.456-464
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• 2013

Objectives: The aim of this study was to investigate the microbial contamination levels in elevators in apartment buildings and to provide information on such microbial contamination. Methods: A total of 144 samples, including from the exterior buttons, interior buttons, elevator handrails, walls, ventilators and airborne bacteria were collected in the morning and afternoon from July to August 2013 for six different elevators. The samples were used to detect sanitary indicator bacteria (total bacteria, coliform, and Escherichia coli), pathogenic bacteria (E. coli O157, L. monocytogenes, Salmonella spp., B. cereus, S. aureus) and fungi. Results: Contamination levels of total bacteria were 0.3-3.8 and 0.0-2.4 log CFU/100 $cm^2$ in the morning and afternoon, respectively. In the case of coliform bacteria, the levels were 0.0-3.7 log CFU/100 $cm^2$ in the morning and 0.0-0.3 log CFU/100 $cm^2$ in the afternoon. However, E. coli was not detected among all samples. Bacillus cereus, pathogenic bacteria, was only detected in 13 (11%) among 144 samples. E. coli O157, L. monocytogenes, Salmonella spp. and S. aureus were not detected among all samples. Comparing the samples collected in the morning and afternoon, we could confirm that the samples in the afternoon were cleaner. Conclusions: This study indicates that the samples in the afternoon were cleaner because these samples were collected following routine cleaning. Also, the levels of contamination in the elevators were low and the sanitary conditions were comparatively well-managed. Therefore it is deemed necessary for elevators be cleaned regularly to provide good conditions for people using elevators.

• 한국식품위생안전성학회지
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• 제31권6호
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• pp.414-419
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• 2016

본 연구는 상추와 오이의 GAP 인증 및 미인증 농가를 대상으로 토양, 용수, 작물 (상추, 오이), 장갑, 포장재 (비닐)에 대한 미생물 오염도를 비교 평가하고 농가의 위생관리 실태를 조사하여 GAP 인증 농가에 대한 미생물학적 안전성 강화를 위한 자료로 활용하고자 하였다. 미생물 오염도 조사 결과 상추 농장의 경우 위생지표세균 오염도는 GAP 인증 농가가 미인증 농가 보다 조금 낮거나 유사하였고, 병원성미생물인 S. aureus와 B. cereus는 GAP 인증 농가의 토양과 용수에서 미인증 농가 보다 높게 검출되었다. 오이농장은 토양의 대장균군과 B. cereus, 장갑의 일반세균 및 대장균군 오염도가 GAP 미인증 농가보다 GAP 인증 농가에서 높았고, 그 외에는 GAP 인증 농가와 미인증 농가가 유사한 오염도를 나타내었다. 전체적으로 결과를 비교했을 때 GAP 인증 농가와 미인증 농가의 미생물 오염도 수준이 크게 차이가 나지 않는 것으로 확인되어 GAP를 인증 받았음에도 불구하고 미생물에 대한 관리는 미흡한 것으로 나타났다. 농가의 위생관리 실태 조사 결과에서는 GAP 인증 농가가 미인증 농가보다는 미생물 오염을 방지하기 위한 노력들을 하고 있는 것으로 확인되었으나, GAP 인증 및 미인증 농가 모두 농업용수의 관리와 작업 시 사용되는 작업자의 장갑 관리에 있어서는 미흡한 것으로 확인되었다. 이상의 연구결과는 농산물의 미생물 오염방지에 대한 방안을 제시하고 GAP 인증을 개선하는데 기초자료로 활용될 수 있을 것으로 판단된다.

• Journal of Dairy Science and Biotechnology
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• 제31권2호
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• pp.153-159
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• 2013

유아 분변, 우분, 염소 분변, 개 분변, 돼지 분변, vaginal tract 채취물, 채소류, 부패한 과일류, 김치, 젓갈, 발효 소세지, 원유, 치즈, 발효유, 청국장, 메주, 막걸리 등 다양한 시료로부터 3,000주의 미생물을 분리하였다. 분리미생물은 L. monocytogenes, E. coli O157:H7, S. enterica serovar Enteritidis에 대해 항균활성을 측정하여 박테리오신 생산 미생물 26주를 최종 선발하였다. 16S rDNA gene sequencing 분석을 통하여 동정한 결과, Enterococcus faecalis(7주), E. faecium(8주), E. hirae(5주), Lactobacillus acidophilus(1주), L. amylovorus(1주), L. curvatus(2주), L. plantarum(1주), Pediococcus acidilactici(1주)와 같이 8종의 미생물이 박테리오신을 생산하는 것으로 확인되었다. 미생물이 생산한 박테리오신은 대부분이 단백질 또는 펩타이드성 물질이어서 인간 또는 동물의 소화효소에 의해 분해되므로 식품에서 안전한 천연보존제로 사용할 수 있을 것으로 기대된다.

• 현장농수산연구지
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• 제23권2호
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• pp.5-14
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• 2021

참당귀의 유효성분인 nodakenin, decursinol, decursin, decursinol angerate 4종의 함량이 균주에 따라 어떤 물질의 변화를 일으키는지를 알아보기 위해 Bacillus EMD17, 9-3, HCD2, #8, 191 5종과 Lactobacillus KCTC 3320, WCP02, S65, P1201 4종 모두 9종류의 균주를 이용하여 발효 실험을 실시하였던 바 아래와 같은 결과를 얻었다. 1. 참당귀의 추출물에 Bacillus균을 접종하여 발효한지 2일 경과한 후부터 지표물질인 decursin과 decursinol angerate의 함량이 급격히 감소하였다. 이는 발효한지 4일이 경과한 후에도 decursin과 decursinol angerate의 함량이 2일째와 동일했다. 반면 발효한지 4일이 경과한 후에 nodakenin과 decursinol의 함량이 높아졌다. 또한 decursin의 함량은 발효한지 6일이 지난 후에는 크게 증가하였다. 2. 참당귀의 추출물에 Bacillus균을 접종 후 nodakenin과 decursinol의 물질변화는 균 종류에 관계없이 거의 나타나지 않았다. Decursin과 decursinol angerate의 유효함량 변화는 Bacillus EMD17, 9-3에서 큰 것으로 나타났다. Decursin과 decursinol angerate의 함량 변화는 Bacillus HCD2, #8, 191균주에서 거의 나타나지 않았다. 3. 참당귀의 추출물에 Lactobacillus KCTC 3320, WCP02, S65, P1201 4종류를 이용하여 발효한지 8일 후에 유효성분 변화를 알아본 결과균의 종류와 상관없이 nodakenin과 decursinol의 함량 변화는 거의 나타나지 않았다. 그러나 Lactobacillus S65, P1201로 발효를 한 경우에는 decursin과 decursinol angerate의 함량에서 변화가 나타났다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.623-625
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• 2000

Bacteriocin을 생산하는 유산균을 김치에서 분리하였고 Lactococcus latis subsp. lactis로 확인 되었으며 bacteriocin의 최대생산조건은 $30^{\circ}C$, 6시간으로 다양한 유산균 및 Pseudomonas synsantha, Acetobacter aceti의 생육을 저해하였고 여러 peptidases에 의해 불활성화되었다. 또한 다양한 범위의 pH와 열처리에 안정하였고 SDS-PAGE결과 약 8 Kda으로 확인되었다.

• 한국동물위생학회지
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• 제42권4호
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• pp.251-255
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• 2019

Wildlife is a bio-indicator of environmental pollution by antimicrobial resistant bacteria or genes, however, there is no information on antimicrobial resistance in wildlife-origin bacteria. This study aimed to investigate the normal microbiota of staphylococci and their antimicrobial resistance in wildlife that did not take any antimicrobials. After sampling and bacterial isolation/identification, antimicrobial resistance profiles were examined by broth microdilution test, Kirby-Bauer disc diffusion test and mecA genetargeted PCR. Of 90 isolates from wildlife, 83 were coagulase-negative staphylococci while only 7 were coagulase-positive staphylococci. Methicillin-resistance was found in 63 (70%) isolates and 35 of 90 (38.9%) isolates were multidrug-resistant staphylococci. When considering that all of the animals did not take any medication or contacted any medical device before the sampling, the results indicate significantly high prevalence of antimicrobial resistance in wild environments. Further study would be necessary to investigate the transmission route of antimicrobial resistance.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.64-71
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• 2022

The discarding of wastes into the environment is a significant problem for many communities. Still, food waste can be used for lactic acid bacteria (LAB) growth. Here, we evaluated three growth media equivalent to de Mann Rogosa Sharpe (MRS), using apple bagasse, yeast waste, fish flour, forage oats, and cheese whey. Cell-free supernatants of eight LAB strains were tested for antimicrobial activity against nine indicator microorganisms. The supernatants were also evaluated for protein content, reducing sugars, pH, and lactic acid concentration. Cell-free supernatants from fish flour broth (FFB) LAB growth were the most effective. The strain Leuconostoc mesenteroides PIM5 presented the best activity in all media. L. mesenteroides CAL14 completely inhibited L. monocytogenes and strongly inhibited Bacillus cereus (91.1%). The strain L. mesenteroides PIM5 consumed more proteins (77.42%) and reducing sugars (56.08%) in FFB than in MRS broth (51.78% and 30.58%, respectively). Culture media formulated with agroindustrial wastes positively improved the antimicrobial activity of selected LAB, probably due to the production of antimicrobial peptides or bacteriocins.

• 환경생물
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• 제39권4호
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• pp.515-522
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• 2021

Jeotgal is a salty and fermented traditional Korean fish sauce. Unlike most other previous studies that investigated samples purchased from retail markets, this study focused on samples of jeotgal with traceable history to Yeonggwang, a timehonored fishing village in Korea. Three jeotgal samples, which were made from small yellow croakers, largehead hairtail, and miscellaneous fish, were selected based on information obtained from interviews with local craftsmen and literature reviews. Bacterial community profiles of the three jeotgal samples were investigated to identify indicator (and potentially core) bacteria for jeotgal ripening. The 16S rRNA gene-based metagenomic analysis revealed that the dominant phyla and classes, (Gammaproteobacteria, Betaproteobacteria, Bacilli, and Clostridia) of the three different jeotgal were identical, albeit with different composition ratios. Diversification was evident beginning at the order level. Interestingly, each dominant order was mainly comprised of single members even at the genus level. The dominant genera included Halomonas, Tetragenococcus, Halanaerobium, Pseudomonas, Massilia, and Lentibacillus. This observed genus-level heterogeneity suggests that there are diverse bacterial signatures in jeotgal and that these can be used as indicators for jeotgal ripening and/or as starters to increase its sensory quality and functionality.

• 식품보건융합연구
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• 제9권6호
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• pp.9-19
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• 2023

Lactobacillus plantarum and Leuconostoc mesenteroides are crucial functional starters and predominant isolates in a wide range of fermented foods, particularly kimchi, whose constituents exhibit bioactive properties. We previously developed a methodology using anion exchange resins to purify peptidyl compounds from Lb. plantarum LBP-K10. Antibacterial cultures of Lb. plantarum LBP-K10 were obtained from the respective cultures' supernatants and filtrates. However, conclusive evidence of the efficacy of kimchi filtrates in eradicating pathogenic bacteria is lacking. We aimed to simulate the potential effects of antibacterial filtrates that contained antibacterial compounds which were derived from cultures of Lb. plantarum LBP-K10. We acquired the kimchi filtrates using a combination of centrifugation and filtration methodologies, without the requirement for inoculation. The filtered liquid from Chinese cabbage kimchi, inoculated with Lb. plantarum LBP-K10 as a starter culture, and the non-inoculated liquid from Chinese cabbage kimchi (referred to as CCK and CCKRef, respectively) were were examined. CCK demonstrated greater inhibitory activity and a more significant bactericidal effect against the bacterial indicator strains. The minimum inhibitory concentration demonstrated comparable outcomes in tests against both Gram-positive and Gram-negative bacteria. This research offers a groundbreaking examination that displays the effectiveness of profiling peptidyl compounds within kimchi filtrates for curing bacterial infections.

• 한국축산식품학회지
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• 제34권5호
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• pp.614-621
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• 2014

This study was conducted to isolate and characterize bacteriocin-producing bacteria against Clostridium perfringens (C. perfringens) from domestic animals to determine their usefulness as probiotics. Bacteriocin-producing bacteria were isolated from pig feces by the spot-on-lawn method. A total of 1,370 bacterial stains were isolated, and six were tentatively selected after identifying the inhibitory activity against the pathogenic indicator C. perfringens KCTC 3269 and KCTC 5100. The selected strains were identified as Enterococcus faecalis (E. faecalis) by 16s rRNA sequencing. Most of the isolated bacterial strains were resistant to 0.5% bile salts for 48 h and remained viable after 2 h at pH 3.0. Some E. faecalis also showed strong inhibitory activity against Listeria monocytogenes KCTC 3569, KCTC 3586 and KCTC 3710. In the present study, we finally selected E. faecalis AP 216 and AP 45 strain based on probiotic selection criteria such as antimicrobial activity against C. perfringens and tolerance to acid and bile salts. The bacteriocins of E. faecalis AP 216 and AP 45 strains were highly thermostable, showing anticlostridial activities even after incubation at $121^{\circ}C$ for 15 min. These bacteriocin-producing bacteria and/or bacteriocins could be used in feed manufacturing as probiotics as an alternative to antibiotics in the livestock industry.