• 농약과학회지
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• 제13권1호
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• pp.45-53
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• 2009

KLF01으로 명명된 세균이 토마토의 뿌리에서 분리 되었고 생화학적, 유전학적 검증을 통해 Lactobacillus sp.로 동종 되었다. In vitro 실험에서 식물성 세균인 Ralstonia solanacearum를 비롯하여, Xanthomonas axonopodis pv. citri, Xanthomonas campestris pv. vesicatoria, Eriwinia pyrifoliae, Eriwinia carotovora subsp. carotovora group에게도 저해 효과를 나타내는 것으로 확인되었다. 고추와 토마토를 이용한 in vivo 실험에서는 특히 R. solanacearum에 대해 대조구와 비교 시들음병의 진행을 저해하는 것으로 관찰되었다.

• 미생물학회지
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• 제54권3호
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• pp.244-253
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• 2018

이 연구는 분리된 토양 세균에 의해 생성된 항균물질의 효과를 평가하기 위해 수행되었다. 2000여개의 세균 분리주 중 Paenibacillus elgii DS381이 여러 인간 피부 상재균과 병원성 세균에 대해 높은 항균활성을 나타내었다. DS381 균주는 agar well diffusion test에서 모든 대상 세균과 효모에 대해 15.3~26.0 mm 직경의 저해대를 형성하였다. DS381이 생성한 항균 펩티드는 모든 대상 미생물에 낮은 최소저해농도 (0.039-5.000 mg/ml)를 나타내었다. DS381 균주는 lipopeptide 같은 생물계면활성제 생산을 나타내었는데, 배양 상등액의 표면장력을 60.0에서 40.3 mN/m으로 낮추었다. DS381은 또한 $1.56{\pm}0.13U/ml$의 chitinase 활성도 나타내었다. 이 결과들은 P. elgii DS381이 일부 중요한 인간 피부 상재균과 병원성 세균에 대한 효율적인 생물제어제로 사용될 수 있음을 가리킨다.

• 한국식품과학회지
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• 제32권6호
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• pp.1336-1340
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• 2000

서울등 5개지역에서 수거한 냉동식품 624건을 대상으로 Y. enterocolitica를 분리하였다. 분리대상 식품군 중 해산물가공품중에서 Y. enterocolitica의 분리율(9.1%)이 가장 높았고, 다음으로 식육가공품(7.7%), 만두류(3.5%), 기타 냉동식품(3.4%)의 순이었으며 냉동피자류(1.7%)는 분리율이 가장 낮았다. 그리고 상반기와 하반기의 분리율이 차이를 보였는데 각각 1.6%와 9.6%로 하반기가 상반기에 비하여 분리율이 6배가 높았다. 냉동식품에서 분리된 Y. enterocolitica 균주는 모두 35개(5.6%)였고, 분리균주의 serotype은 O:5(9균주)와 O:1,2(1균주)이었다. 이외의 나머지 25개 균주는 본 연구에서 사용한 항혈청에 응집반응을 보이지 않아 혈청형을 typing할 수 없었다. 그리고 이들 균주를 biotype한 결과 모두 비병원성인 biotype 1A이었으며 중합효소연쇄반응(PCR)으로 확인 결과 또한 모두 비병원성으로 판명되었다.

• 한국동물위생학회지
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• 제40권4호
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• pp.265-275
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• 2017

The production of enzymes that help digestion, assimilation of essential nutrients, and prevent pathogenic bacteria are important for probiotics used in aquaculture. The objective of this study was to investigate enzyme activities for macromolecular organic matters and antimicrobial properties of the selected potential probiotics isolated from gut of surf clam (Tresus keenae) against well-known shellfish-pathogenic bacteria. Among 65 isolates from guts of 60 surf clams, seven Bacillus strains with outstanding degradation capability of macromolecule organic matter were selected as potential probiotics as follows: TKI01 (B. vietnamensis), TKI02, TKI26 (B. thuringiensis), TKI14, TKI32, TKI42 (B. amyloliquefaciens), and TKI18 (B. stratosphericus). After in vitro antimicrobial activity test was performed against five shellfish-pathogenic bacteria including Listonella anguillarum, Vibrio parahaemolyticus, V. splendidus, V. harveyi, V. tubiashii, PCR assay was performed to detect bacteriocin-producing strain. PCR results revealed that the five Bacillus strains possessed diverse bacteriocin genes including ericinA, coagulin, surfactin, iturin, bacyllomicin, fengycin, bacylisin, subtilin, and lantibiotics. In the present study, the selected seven Bacillus strains showed different enzyme activities according to types of macromolecule organic matters. And their antimicrobial activities varied based on the species of pathogenic bacteria. In addition, at least five Bacillus strains had genetic potential to produce several natural lipopeptide antibiotics that may help biological control of surf clam aquaculture. Therefore, mixed use of probiotics might show co-operative effect and increase the efficiency of probiotics rather than separate use. To the best of our knowledge, it is the first report on antimicrobial properties of Bacillus species isolated from surf clam.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.134-134
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• 2017

Recently, host-induced gene silencing (HIGS) system has been successfully applied into development of resistant crops against insects, fungal and viral pathogens. To test HIGS-mediated resistance in rice against rice blast fungus, Magnaporthe oryzae, we first tested possibility of movement of small non-coding RNA from rice cells to rice blast fungus. The rice blast fungus expressing GFP transgene were inoculated to transgenic rice plants ectopically expressing dsRNAi construct targeting fungal GFP gene. Expression of dsRNAi construct for GFP gene in transgenic plants significantly suppressed GFP expression in infected fungal cells indicating that small RNAs generated in plant cells can move into infected fungal cells and efficiently suppress the expression of fungal GFP gene. Consistent with these results, expression of dsRNAi constructs against 3 fungal pathogenic genes of M. oryzae in transgenic rice specifically and efficiently suppressed not only the expression of fungal pathogenic genes, but also fungal infection. The conidia of M. oryzae applied on leaf sheath of transgenic rice expressing dsRNAs against 3 fungal pathogenic genes showed abnormal development of primary hyphae and malfunction of appressorium, which is consistent with the phenotypes of corresponding fungal knock-out mutants. Taken these results together, here, we suggest a novel strategy for development of antifungal crops by means of HIGS system.

• 한국수산과학회지
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• 제35권6호
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• pp.578-582
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• 2002

양식어류 질병 세균에 대한 31종의 천연물을 $70\%$ ethanol로 추출하여 항균효과를 조사하였다. 그 중에서 망태버섯 ethanol 추출물이 비교적 높은 활성을 나타내었으며, 망태버섯을 극성이 낮은 dichlorornethane, ethyl acetate, n-buthanol, water의 순서로 분획하여 항균효과를 본 결과 ethyl acetate 추출물에서 모든 균주에대한 clear zone을 형성하여 항균효과가 보였다. 또한, 망태버섯로부터의 ethyl acetate 추출물을 Si-chromatography를 이용하여 fraction별 7개로 분획하여 항균효과를 조사한 결과 Fraction 2 (Hx :EtAOc, 3: 1)에서는 L. anguillarum에 대해 가장 항균효과가 뛰어났으며, Fraction 5 (DCM:MeOH, 5: 1)에서 5. iniae가 가장 높았다. 그 중에서 세 균주에 대해서 공통적으로 항균활성이 높은 것은 Fraction 5로 나타났다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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• pp.53-60
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• 2000

Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer, which has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by the API test and some characteristics. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the non-pathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by Lactococcus lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against non-pathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely disappeared by protease XIV or ${\alpha}$-chymotrypsin. The inhibitory activities of lacticin BH5 were detected during treatments up to 100$^{\circ}C$ for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. The cell concentration and bacteriocin production in strain BH5 were maximum when grown at 30$^{\circ}C$ in a modified MRS medium supplemented with 0.5% tryptone, 1.0% yeast extract, and 0.5% beef extract as nitrogen sources. It demonstrated a typical bactericidal mode of inhibition against Micrococcus flavus ATCC 10240. Lacticin BH5 was purified through ammonium sulfate precipitation, ethanol precipitation, and CM-Sepharose column chromatography. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3.7 kDa, by the direct detection of bactericidal activity after SDS-PAGE. Mutant strain NO141 which was isolated by nitrosoguanidine mutagenesis produced about 4 fold more bacteriocin than the wild type.

• Journal of Microbiology
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• 제45권5호
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• pp.453-459
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• 2007

We developed a multiplex PCR (mPCR) assay to simultaneously detect Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Ureaplasma urealyticum, Corynebacterium spp. and seudomona aeruginosa. This method employs a single tube and multiple specific primers which yield 200, 281, 346, 423, 542, and 1,427 bp PCR products, respectively. All the PCR products were easily detected by agarose gel electrophoresis and were sequenced to confirm the specificity of the reactions. To test this method, DNA extracted from urine samples was collected from 96 sexually transmitted disease or prostatitis patients at a local hospital clinical center, and were subjected to the mPCR assay. The resulting amplicons were cloned and sequenced to exactly match the sequences of known pathogenic isolates. N. gonorrhoeae and Corynebacterium spp. were the most frequently observed pathogens found in the STDs and prostatitis patients, respectively. Unexpectedly, P. aeruginosa was also detected in some of the STD and prostatitis samples. More than one pathogen species was found in 10% and 80.7% of STD and prostatitis samples, respectively, indicating that STD and prostatitis patients may have other undiagnosed and associates. The sensitivity of the assay was determined by sing purified DNA from six pathogenic laboratory strains and revealed that this technique could detect pathogenic DNA at concentrations ranging from 0.018 to $1.899\;pg/{\mu}l$. Moreover, the specificities of this assay were found to be highly efficient. Thus, this mPCR assay may be useful for the rapid diagnosis of causative infectious STDs and prostatitis. useful for the infectious STDs and prostatitis.

• 한국양식학회지
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• 제10권1호
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• pp.9-15
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• 1997

여천군 가막만에서 해산어류의 어병발생은 20^{\circ}C$이상인 시기에 집중적으로 발생하였다. 어종별 병원성생물은 넙치가 Vibrio sp., Edwardsiella sp., Streptococcus sp., Vibrio+Edwardsiella sp., Streptococcus sp.+Microcotyle sp,+Caligus sp. 및 Trichodina sp.에 감염, 조피볼락은 원인 불명 (선회병; 원인생물은 포도상구균으로 1994년에 동정함), 림포시스티스증, , Vibro+Microcotyle sp. 및 Streptococcus sp.+Micrococcus sp.에 감염, 농어는 림포시스티스증, Vibro sp., Vibro+Streptococcus sp. 및 Streptococcus sp.+Microcotyle sp.+Caligus sp.에 감염, 참돔은 Edwardsiella sp.에 각각 감염되었다. 조사지점 7개소 중 1, 5 및 6번 가두리 양식장은 20^{\circ}C$이상인 6월부터 10월까지 연속적으로 어병이 발생하였다. 약제감수성시험에서 Vibrio sp. (KS-9303)는 옥시테트라사이크린, 클로람페니콜, Edwardsiella sp. (KP-9315)는 옥시테트라사이클린, Flaxibacter sp. (KP-9318)는 옥시테트라사이클린, 옥소린산 및 클로람페니콜, 그리고 Streptococcus sp. (KP-9319)는 에리스로마이신, 옥시테트라사이클린 및 클로람페니콜 순으로 감수성이 나타났다.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1240-1245
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• 2008

Kimbab is the most popular ready-to-eat (RTE) food in Korea. A rapid detection method based on multiplex PCR technique was developed for detection of major food-borne pathogens like Salmonella spp., Shigella spp., Bacillus cereus, Listeria monocytongenes, and Staphylococcus aureus. Specific bands were obtained as 108 bp (Sau, S. aureus), 284 bp (Sal, S. enterica, S. enteritids, and S. typhmurium), 404 bp (Lmo, L. monocytogenes), 475 bp (Bce, B. cereus), and 600 bp (Shi, S. flexineri and S. sonnei). Visible cell numbers varied from 4.14-5.03, 3.61-4.47, and 4.10-5.11 log CFU/g in randomly collected June, July, and August samples, respectively. Among the 30 kimbab samples obtained 83.3% samples were contaminated and 16.7% samples were free from contamination. The highest rate of contamination was with S. aureus (56.7%) followed by B. cereus (43.3%), Salmonella spp. (36.7%), Shigella spp. (13.3%), and L. monocytogenes (6.7%). The identification of the pathogenic species could be faster using one polymerase chain reaction (PCR) and the ability to test for food-borne pathogenic species in kimbab will save time and increase the ability to assure its quality.