• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.48-55
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• 2004

Six strains of an obligate predatory bdellovibrio isolate that preys on Burkholderia glumae in rice paddy field water and rhizosphere soil, were identified and characterized. The numbers of Bdellovibrio cells varied from $3.2{\times}10^3$ to $9.2{\times}10^3$ plaque-forming unit/g after enrichment in cells of B. glumae. Prey range tests with six Bdellovibrio strains and 17 prey strains of rice-pathogenic, antibiosis-related, or nitrogen-fixing bacteria resulted in unique predation patterns in related prey cells. Strain BG282 had the widest prey range on 7 plant pathogenic bacteria among the 17 prey strains tested. However, no predation occurred with strains of Azospirillum brasilense, Paenibacillus polymyxa, Pseudomonas fluorescens, P. putida, and Serratia marcescens that are associated with antibiosis or nitrogen fixation in the rice ecosystem. Identification was confirmed by the presence of typical bdelloplast in the prey cells of B. glumae and by a PCR assay using B. bacteriovorus-specific primers. Furthermore, 16S rDNA sequencing of the six bdellovibrio strains showed a homology range of 97.2% to 99.2% to the type strain of B. bacteriovorus.

• 한국토양비료학회지
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• 제41권5호
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• pp.362-368
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• 2008

항진균성 활성을 가지는 저영양세균을 분리하기 위하여 토양시료는 경북 영양, 충북 제천, 충북 음성, 충북 괴산, 충남 논산 등지의 고추 밭에서 수집하였고 R2A배지를 이용하여 평판희석법으로 9,354여 균주의 저영양세균을 분리하였다. 분리된 저영양세균중 고추역병에 강한 활성을 가지는 1A 균주를 선발 하였으며 16S rDNA 와 표준균주(B. vallismortis, B. mojavensis)를 이용한 생리, 생화학적 실험으로 B. vallismortis로 최종동정 되었다. 1A균주는 Magnaporthe 균을 제외하고 Phytophthora, Collectotrichum, Botrytis, Fusarium 균등에서 폭넓게 강한 활성을 나타내었다. 고추 유묘검정에서 대조구가 89%정도의 발병율을 보인 반면에 1A 처리구에서는 29%의 발병율을 나타내어 고추역병의 길항균으로써의 미생물제제 가능성이 있는 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.529-536
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• 2003

The growth-inhibitory activity of Cassia tora seed-derived materials against seven intestinal bacteria was examined in vitro, and compared with that of anthraquinone, anthraflavine, anthrarufin, and 1-hydroxyanthraquinone. The active constituent of C. tore seeds was characterized as quinizarin, using various spectroscopic analyses. The growth responses varied depending on the compound, dose, and bacterial strain tested. At 1 mg/disk, quinizarin exhibited a strong inhibition of Clostridium perfringens and moderate inhibition of Staphylococcus aureus without any adverse effects on the growth of Bifidobacterium adolescentis, B. bifidum, B. longum, and Lactobacillus casei. Furthermore, the isolate at 0.1 mg/disk showed moderate and no activity against C. perfringens and S. aureus. The structure-activity relationship revealed that anthrarufin, anthraflavine, and quinizarin moderately inhibited the growth of S. aureus. However. anthraquinone and 1-hydroxyanthraquinone did not inhibit the human intestinal bacteria tested. As for the morphological effect of 1 mg/disk quinizarin, most strains of C. perfringens were damaged and disappeared, indicating that the strong activity of quinizarin was morphologically exhibited against C. perfringens. The inhibitory effect on aflatoxin $B_1$ biotransformation by anthraquinones revealed that anthrarufin ($IC_50,\;11.49\mu\textrm{M}$) anthraflavine ($IC_50,\;26.94\mu\textrm{M}$), and quinizarin ($IC_50,\;4.12\mu\textrm{M}$), were potent inhibitors of aflatoxin ${B_1}-8,9-epoxide$ formation. However, anthraquinone and 1-hydroxyanthraquinone did not inhibit the mouse liver microsomal sample to convert aflatoxin $B_1$ to aflatoxin ${B_1}-8,9-epoxide$. These results indicate that the two hydroxyl groups on A ring of anthraquinones may be essential for inhibiting the formation of aflatoxin ${B_1}-8,9-epoxide$. Accordingly, as naturally occurring inhibitory agents, the C. tora seed-derived materials described could be useful as a preventive agent against diseases caused by harmful intestinal bacteria, such as clostridia, and as an inhibitory agent for the mouse liver microsomal conversion of aflatoxin $B_1$ to aflatoxin ${B_1}-8,9-epoxide$.

• 한국자연치유학회지
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• 제8권2호
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• pp.71-77
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• 2019

목적: 특허 받은 황토 면 원단의 원적외선 방사율 및 면 원단을 20회까지 세탁을 하였을 때에 어떠한 미생물이 존재하는지를 조사하여 분리 동정하는 것이 목적이었다. 방법: 원적외선 방사능 측정기와 미생물을 영양배지에 배양하여 증식하는 단일 콜로니를 이용하여 16S rRNA법으로 동정하였다. 결과: 황토이불 면의 원적외선의 방사율은 40℃에서 5~20 ㎛에서 0.902(90.2%)이었고, 방사에너지는 3.63 × 10² w/m²로 높게 나타났다. 황토 이불 면 원단에서 2.0 × 10² cells/ml의 생균수가 존재하였고, 그리고 일반 면 원단에서는 생균이 발견되지 않았다. 단일 콜로니로 분리된 B-2 균주의 16S rRNA의 염기서열은 1,419 bases이었고, A-4균주의 염기서열은 1,284 bases이었다. 이 두 균주의 16S rRNA의 염기서열은 Bacillus 속 세균들과 높은 상동성을 보이었다. B-2 균주는 B. aryabhattai EF114313의 16S rRNA 염기서열과 99.0% 그리고 A-4균주는 B. bingmayongensis AKCS01000011의 16S rRNA 염기서열과 99.0%의 높은 상동성이 나타났다. 상기의 결과들을 활용하여 16S rRNA을 이용하여 유연관계를 조사하여 콜로니 균주 B-2를 B. aryabhattai BJ-2 균주로, A-4를 B. bingmayongensis BJ-4 균주로 최종 동정하였다. 결론: 황토 이불 면 원단에서 두 종류의 간균을 발견하였고, 이불 면 원단이 높은 량의 원적외선 및 원적외선 방사에너지가 발산하므로 유용하게 이용될 수 있다고 본다.

• Environmental Engineering Research
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• 제15권1호
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• pp.15-21
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• 2010

This study was conducted to evaluated seawater bacteria and their seasonal characteristics in the arsenic contaminated coastal seawater of Yeosu Bay, the Republic of Korea. Arsenite-oxidizing bacteria play an important role in the seawater of the arsenic contaminated bay, with a variety of arsenic resistance system (ars) genotypes being present during summer. Specifically, Bacillus sp. strain SeaH-As22w (FJ607342), isolated from the bay, were found to contain the arsB, arrA and aoxR type operons, which are involved in arsenic resistance. The isolated bacteria showed relatively high tolerance to sodium arsenite (III; $NaAsO_2$) at concentrations as high as 50 mM. Additionally, batch seawater experiments showed that Bacillus sp. strain SeaH-As22w completely oxidized 1 mM of As (III) to As (V) within 10 days. Ecologically, the arsenic-oxidizing potential plays an important role in arsenic toxicity and mobility in As-contaminated coastal seawater of Yeosu Bay during all seasons because it facilitates the activity of Bacillus sp. groups.

• 한국동물위생학회지
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• 제33권1호
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• pp.29-35
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• 2010

This study was performed to test the hypothesis that Brucella abortus strain RB51 (SRB51) might protect Korean indigenous mongrel dog against challenge with either virulent B. abortus biotype 1 or B. canis. A total of 12 Korean mongrel dogs were divided into four groups (Group A, B, C and D). Dogs belonging to Group A and C were inoculated subcutaneously with $1{\times}10^9$ CFU of SRB51 in 1ml of sterile phosphate buffered saline (PBS). Dogs of Group B and D were inoculated subcutaneously with 1ml of sterile PBS as control. At 12 weeks post vaccination, dogs of Group A and B were challenged by oral inoculation of virulent strain of B. canis ($5.0{\times}10^9$ CFU) and dogs of Group C and D were challenged by oral inoculation of virulent strain of B. abortus biotype 1 ($4.4{\times}10^{10}$ CFU). The serum antibodies titers in all dogs were monitored at regular interval for eight weeks after challenge (AC) by standard tube agglutination test, plate agglutination test, rose bengal test, 2-mercaptoethanol rapid slide agglutination test and 2-mercaptoethanol tube agglutination test. No antibody titers in Group A and C was detected. Also, the challenge strains were not found from blood of all dogs of Group A and C from 1 week AC till the end of the experiment by culture and modified AMOS-PCR, whereas B. canis and B. abortus challenge strains were detected from blood of Group B and D, respectively. In addition, neither of two challenge bacteria was recovered from liver, spleen, kidneys, lymph nodes and reproductive tracts of Group A and C dogs after postmortem. However, B. canis and B. abortus challenge strains were isolated from these tissues of Group B and D, respectively. These data suggest that SRB51 could be a promising vaccine candidate for immunizing dogs to control canine brucellosis caused by B. canis or B. abortus.

• 한국산학기술학회논문지
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• 제17권7호
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• pp.442-450
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• 2016

본 연구의 목적은 대나무 줄기 마디 부분의 표면에서 처음 발견 되었으나, 아직까지는 연구가 미흡한 신 균주 Bacillus amyloliquefaciens NBF11-1로 발효한 청국장 추출물의 항균 활성을 알아보려고 한다. 청국장 전통 발효 균주인 Bacillus subtilis NG24를 대조 군으로 하고, 비교 분석을 실시하였다. 실험 방법은 항균 활성, 최소 억제 농도(MIC)와 열 및 pH 안정성을 측정하였다. 항균 활성 실험 결과, 병원성 6종 균주에서 그람 양성 균주 C.perfringens, S.aureus와 그람 음성 균주 A.faecalis, E.coli에서 B.amyloliquefaciens NBF11-1이 B.subtilis NG24에 비해 강한 항균 활성을 나타내었다. 최소 억제 농도 실험 결과, C.perfringens, S.aureus, A.faecalis, E.coli에서 B.amyloliquefaciens NBF11-1이 B.subtilis NG24에 비해 0.01 %, 0.21 %, 0.45 %, 0.29 %의 농도로 억제 효과를 나타내었다. 열과 pH 안정성 실험 결과, B.subtilis NG24와 더불어 B.amyloliquefaciens NBF11-1 청국장 추출물은 $121^{\circ}C$, 15분 간 열처리와 pH 2-10 처리에 의한 안정성에서 활성이 감소하지 않았고, 열과 pH 실험에서 비교적 안정하였다.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.164-169
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• 1995

An endogenous cryptic plasmid, pBL1, which has been used to construct plasmid vectors for coryneform bacteria producing amino acids, was eliminated from Brevibacterium lactofermentum. The pBL1 was partially digested with Sau3AI and the resulting DNA fragments were subcloned into a suicide vector pEM1 which contains a kanamycin-resistant (km$^{r}$) gene. KM$^{r}$ B. lactofermentum transconjugants were obtained by conjugal transfer of the pEM1 derivatives containing pBL1 DNA fragments from Escherichia coli into B. lactofermentum. A km$^{r}$ transconjugant was analyzed to contain a plasmid pEB14, which occurred in vivo by homologous recombination between pBL1 and the conjugal-transferred plasmid. The pEB14 including the pEM1-derived km$^{r}$ gene was found to be lost concomitantly with km$^{r}$ phenotype, resulting in the construction of a pBL1-free strain of B lactofermentum. Based on transformation efficiencies and plasmid stability, the resultant pBL1- free strain is more useful than wild strain as a host cell for genetic manipulation. It could be concluded that foreign plasmid DNAs are efficiently isolated and analyzed from the pBL1-free strain because of the absence of endogenous pBL1 plasmid.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.96-100
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• 2004

토양 시료를 대상으로 chlorothalonil을 함유한 최소배지에서의 집식배양과 배양 추 HPLC에 의한 잔류분석을 통해 chlorothalonil의 제거 능력이 우수한 균주 Ochrobactrum sp. SH35B를 분리하였다. 분리균 SH35B는 1/10 LB 배지에 함유된 10 ppm의 chlorothalonil을 30시간만에 완전히 제거하였으며, 20 ppm의 chlorothalonil의 경우 30시간 동안 88%를 제거하였다. 분리균의 Glu-SH함량과 glutathione S-transferase활성은 각각 1.33및 62.1 nmol/mg이었으며, 대조균인 E. coli나 B. subtilis 보다 높은 것으로 나타났다. 이상의 결과로부터 chlorothalonil의 전환에 있어서 세포내의 Glu-SH 함량과 glutathione S-transferase 활성 이 중요한 인자로 작용하는 것으로 생각된다.

• 미생물학회지
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• 제33권2호
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• pp.136-141
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• 1997

한국의 전통 발효식품인 된장에서 단백질 분해효소를 분비하는 미생물의 존재를 규명하기 위해, skim milk 한천배지를 이용하여 투명환을 보이는 균주들을 얻었고, 각종 생리 및 생화학적 검사, VITEK system, MIDI system을 통해 이들 중, JH-1, SH-5, SH-7의 3 strain이 Bacillus cereus임을 동정하였다. JH-1과 SH-5 균주가 분비하는 단백질 분해효소는 pH 9와 40^{\circ}C.$에서 최적활성을 보였으며, SH-7 균주는 pH 8과 50^{\circ}C.$에서 최적활성을 보였다. 또한 이들 3균주는 blood agar plate에서 용혈능력을 보였다.