새우양식장에서 분리한 Lactobacillus sp. JK-8의 생리적 특성

천재우,마채우,오계헌,Chun Jae-Woo,Ma Chae-Woo,Oh Kye-Heon 한국미생물학회 2005 미생물학회지 Vol.41 No.1

이 연구는 새우양식장에서 분리된 Lactobacillus sp. JK-8의 생리적 특성을 규명하기 위하여 실시되었다. 균주 JK-8을 MRS 배지에서 배양하였고, 형태 및 생리학적 특성에 대하여 조사하였으며, BIOLOG시험을 통하여 이 세균은 Lactobacillus속으로 동정되었다. 배양기간 동안에 균주 JK-8의 생장과 PH변화를 조사하였으며, 생성되는 유기산(lactic acid와 acetic acid)은 JK-8 배양의 생장과 비례하는 것을 확인하였다. Lactic acid와 acetic acid의 농도는 각각 192.8 mM과 43.6 mM이었으며, 초기 pH 7.0은 배양기간동안 3.8로 감소하였다. 8가지 대상 세균에 대하여 5배로 농축된 배양 상등액에 처리하여 살균효과를 조사하였으며, 이 연구에서 모든 대상 세균들은 배양3시간 이내에 완전히 살균되었다. pH조절을 하지 안은 JK-8 배양에서 대상세균들에 대한 항균효과가 있는 것이 관찰되었으나, pH가 조절된 배양에서는 거의 관찰되지 않았다. 대사산물로서 lactic acid와 acetic acid의 분리하기 위하여 HPLC를 사용하였으며, GC-MS를 이용하여 이들 대사산물을 확인하였다. The purpose of this work was to investigate the physiological characteristics of Lactobacillus sp. JK-8 isolated from a shrimp aquaculture pond. The strain JK-8 was grown on MRS media, and morphological and physiological characteristics of the strain were examined. The bacterium was identified as a strain of the genus Lactobacillus on the basis of BIOLOG test. Strain JK-8 produced both lactic acid and acetic acid, which were responsible for the pH decrease during growth. Concentrations of lactic acid and acetic acid increased to 192.8 mM and 43.6 mM, respectively, and the initial pH 7.0 of the cultures decreased to 3.8 at the end of incubaction. The bacteriocidal effect against eight target bacteria was examined with 5-fold concentrated culture supernatants. All bacteria tested in this work were completely killed within 3 hrs after treatment with the culture supernatant. The bacteriocidal effects were clearly observed, only when the pH of the culture supernatants were not adjusted. HPLC was used to reslove lactic acid and acetic acid in the culture solution, and GC-MS was used to verify the metabolites.

새우양식장에서 분리한 Bacillus sp. CK-10과 Bacillus sp. CK-13에 의한 질소와 인의 제거

천재우(Jae-Woo Chun),마채우(Chae-Woo Ma),이상현(Sang-Hyun Lee),오계헌(Kye-Heon Oh) 한국생물공학회 2005 KSBB Journal Vol.20 No.2

식품 및 환경, 기타 새우양식장에서 분리한 해양세균 Bacillus sp. CK-10과 Bacillus sp. CK-13에 의한 양식사료에 포함된 질소와 인의 동시제거

천재우 ( Jae Woo Chun ),마채우 ( Chae Woo Ma ),강형일 ( Hyung Yeel Kahng ),오계헌 ( Kye Heon Oh ) 한국미생물생명공학회 2005 한국미생물·생명공학회지 Vol.33 No.2

차 카테킨 EGCG (Epigallocatechin Gallate)의 구강세균에 대한 살균효과

유미옥,천재우,오계헌,Yu Mi-Ok,Chun Jae-Woo,Oh Kye-Heon 한국미생물학회 2004 미생물학회지 Vol.40 No.4

본 연구는 차 카테킨인 EGCG (epigallocatechin gallate)에 의한 구강세균의 살균효과를 조사하기 위하여 수행되었다. 초기 세포밀도 $10^{7}$ cell/ml의 대상 세균에 대한 항세균 활성은 EGCG 1ml당 5mg에서 조사하였다. 선택 또는 복합배지상에서 집락생성단위(colony-forming unit, CFU)에 근거하여 EGCG의 항세균 활성은 농도에 비례하는 것을 확인하였다. Streptococcus mutans와 Streptococcus sobrinus는 5mg/ml의 EGCG에서 8시간 이내에 완전히 살균되었다. Lactobacillus acidophilus와 Lactobacillus plantarum도 동일한 조건에서 각각 2시간과 4시간 이내에 살균되었다. 2.5 mg/ml의 EGCG로 처리한 사람의 타액에서 유래하는 총 구강세균의 생존율을 BHI 고체배지상에서 조사하였으며, 총 구강세균은 10시간 이내에 완전히 살균되었다. MS 고체배지상에서 S. mitis and S. salivarius의 집락은 감소되었으며 배양 12시간 이내에서는 집락은 관찰되지 않았다. 그 결과, EGCG는 입냄새와 치석의 원인이 되는 구강세균을 살균시키고 충치를 예방하는 자연적이며 효과적인 물질임이 입증되었다. The purpose of this work was to investigate the effect oftea catechin, epigallocatechin gallate (EGCG) on killing of oral bacteria. The antibacterial activity of 2.5 mg/ml and 5.0 mg/ml EGCG was investigated for target bacteria of which initial cell number was approximately adjusted to $10^{7}ml$. The antibacterial activity of EGCG was proportional to the concentration according to colony-forming unit(CFU) of target bacteria enumerating on selective and complex media. Streptococcus mutans and Streptococcus sobrinus at 5mg/ml EGCG were completely killed within 8 hrs. Lactobacillus plantarum and Lactobacillus acidophilus were also killed within 2 hrs and 4 hrs under the same conditions, respectively. Oral bacteria at 2.5 mg/ml EGCG were completely killed within 10 hr. Colony numvers of S. mitis and S. salivarius treated with 2.5 mg/ml EGCG were decreased on MS solid media and no colony was observed on the media within 12 hrs. In consequence, EGCG would be a natural and effective compound that kill oral bacteria being caused of bad breath, plaque and gingivitis, and for preventing and treating dental caries.

방향족 화합물인 Aniline, Benzoate, p-Hydroxybenzoate를 분해하는 Delftia sp. JK-2에서 분리된 Dioxygenases의 특성연구

황선영(Seon-Young Hwang),천재우(Jae-Woo Chun),강형일(Hyung-Yeel Kahng),오계현(Kye-Heon Oh) 한국생물공학회 2004 KSBB Journal Vol.19 No.1

토양에서 분리된 Acrylamide 분해 세균 JK-7의 분리 및 특성

천재우,오계현 순천향대학교 기초과학연구소 2003 순천향자연과학연구 논문집 Vol.9 No.2

The feasibility of using pure culture for acrylamide degradation, with the ultimate aim of application for biological treatment process, was explored. The present study reports on the test cultures which were developed to grow aerobically with acrylamide as the sole source carbon and nitrogen. A bacterial isolate, strain JK-7 was isolated from paddy soil samples, Strain JK-7 could degrade 50 mM acrylamide completely within 72 hours of incubation. Major intermediates resulting from acrylamide degradation were not detected with the HPLC methodology except acrylic acid which appeared to accumulate transiently in the growth medium. Initial pH 7.2 of the cultures became to increase 8.4 at the end of incubation. When JK-7 cells were grown at over 100 mM acrylamide, there was a pause of cell growth, resulting in a reduction in the rates of acrylamide degradation. Survival test revealed that cells exposed to low concentrations of acrylamide enable to the strain JK-7 to survive at a lethal concentration of 100 mM acrylamide. The relationships between the acrylamide degradation by JK-7 and several relevant physicochemical environmental parameters were examained. The effect of supplemented carbons(e.g., glucose, fructose, citrate, succinate) on the acrylamide degradation by the test culture of JK-7 was evaluared. The results indicated that the addition of carbons accelerated the bacterial growth and acrylamide degradation compared to in the absence of supplemented carbons. The effect of supplemented nitrogens on the degradation was monitored. Increasing concentrations of yeast extract resulted in higher growth yield, based on the turbidity measurement, and complete degradation of acrylamide. However, acrylamide degradation was essentially uninfluenced by the addition of (NH_(4))_(2)So_(4),NH_(4)Cl, or urea. The bacterium was identified as belonging to the genus Pseudomonas in the basis of use BIOLOG test, and designated as Pseudomonas sp. JK-7

해양에서 분리한 Lantobacillus sp. JK-8에 의한 질병원인 세균의 살균효과

천재우,마채우,오계헌 순천향대학교 기초과학연구소 2004 순천향자연과학연구 논문집 Vol.10 No.2

The purpose of this work was to investigate for killing effect of disease-causing bacteria by Lactobacillus sp. JK-8 isolated from marine environment. Initially, a bacterial culture, strain JK-8 was developed to grow no MRS media. The bacterium was identified as genus Lactobacillus on the basis of BIOLOG test, and designated as Lactobacillus sp. JK-8. The intial pH 7 of the cultures became to decrease pH 3.85 at the end of incubaction according to the growth of Lactobacillus sp. JK-8. The antibacterial activity using plate diffusion method against target bacteria was determined with 5-fold concentrate of cell-free culture supernatant. Excellent killing effect of target bacteria was achieved. The inhibition zone obtained with culture supernatant were in between 14 mm and 20 mm. Killing rate of pathogenic bacteria was examined with cell-free concentrated supernatants. All bacteria tested in this work completely killed within 3 hrs of incubaction.

Tea polyphenol에 노출된 식중독 원인세균 Listeria monocytogenes의 살균

유미옥,천재우,오계헌 순천향대학교 기초과학연구소 2004 순천향자연과학연구 논문집 Vol.10 No.2

The aim of this work was to investigate the killing effect of the food-poisoning bacterium, Listeria monocytogenes exposed by tea polyphenol (TPP) extracted from green tea. The stress shock proteins, which contribute to the resistance of the cytotoxic effect of TPP, were induced at different TPP concentration in exponentially growing cultures of L. monocygenes. This response involved the induction of a 70-kDa DnaK and a 60-kDa GroEL monoclonal antibodies, characterized by SDS-PAGE and Western blot by the use of the anti-DanK and anti-GroEL monoclonal antibodies. Survival of L.monocytogenes with time in the presence of different concentrations of TPP was monitored, and viable counts paralleled the induction of the stress shock proteins in this strain. This strain killed in the concentration of 1,000㎍/㎖ TPP within 4 hours of incubation. Scanning electron microscopy for the cells treated with 1,000㎍/㎖ for 12 hours showed the presence of perforations and irregular rod shaped with wrinkled surfaces.

녹차추출물에 의한 식중독 원인균인 장내세균 Plesiomonas shigelloides의 세포반응

유미옥,천재우,오계헌 순천향대학교 기초과학연구소 2002 순천향자연과학연구 논문집 Vol.8 No.2

The aim of this work was to investigate the cellular responses in the food-poisoning bacterium, Plesimonas shigelloids in response to tea polyphenol (TPP) extracted from green tea. The stress shock proteins, which contribute to the resistance of the cytotoxic effect of TPP, were induced at different TPP concentrations in exponentially growing culture of P. shigelloides. This response involved the induction of a 70-kDa DnaK and a 60-kDa GroEL monoclonal antibodies, characterized by SDS-PAGE and Western blot by the use of the anti-DnaK and anti-GroEL monoclonal antibodies. Survival of P. shigelloides with time in the presence of different concentrations of TPP was monitored, and viable counts paralleled the induction of the stress shock proteins in this strain. This strain killed in the concentration of 1,000 ㎍/㎖ TPP within 2 hours of incubation. Scanning electron microscopy for the cells treated with 10,000 ㎍/㎖ for 12 hours showed the presence of perforations and irregular rod shaped with wrinkled surfaces.