• 농약과학회지
• /
• 제13권1호
• /
• pp.45-53
• /
• 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.

• Applied Biological Chemistry
• /
• 제48권1호
• /
• pp.48-52
• /
• 2005

종자발아실험과 뿌리에서의 집락 형성실험으로 고추와 토마토의 근권 토양에서 plant growth promoting rhizobacteria(PGPR) 균주를 선발하였다. 그 중 포트실험에서 종자처리와 토양 관주처리 하였을 때 60% 이상 풋마름병 방제효과를 나타낸 SKU-78 균주에 대해서 포장에서의 방제효과 검증에 의해 생물농약으로의 개발 가능성을 확인하였으며, 생화학적 특성조사와 16S rDNA sequence 분석에 의해 SKU-78 균주를 Bacillus sp. SKU-78로 동정하였다.

• Journal of Microbiology and Biotechnology
• /
• 제17권11호
• /
• pp.1765-1771
• /
• 2007

A polymerase chain reaction (PCR)-based method was developed to detect the DNA of Ralstonia solanacearum, the causal agent of bacterial wilt in various crop plants. One pair of primers (RALSF and RALSR), designed using cytochrome c1 signal peptide sequences specific to R. solanacearum, produced a PCR product of 932 bp from 13 isolates of R. solanacearum from several countries. The primer specificity was then tested using DNA from 21 isolates of Ralstonia, Pseudomonas, Burkholderia, Xanthomonas, and Fusarium oxysporum f. sp. dianthi. The specificity of the cytochrome c1 signal peptide sequences in R. solanacearum was further confirmed by a DNA-dot blot analysis. Moreover, the primer pair was able to detect the pathogen in artificially inoculated soil and tomato plants. Therefore, the present results indicate that the primer pair can be effectively used for the detection of R. solanacearum in soil and host plants.

• 대한환경공학회지
• /
• 제32권12호
• /
• pp.1094-1101
• /
• 2010

낙동강, 회동 및 기장에서 채집한 sediment의 미생물 군집을 FISH 분석을 통하여 조사한 결과, ${\alpha}$ 그룹, Acidobacter 그룹 및 Cyanobacter 그룹의 분포비율이 가장 높았으며 전체적으로 서로 유사한 분포 특성을 나타내었다. 각각의 sediment를 접종한 MFC 농화배양 이후의 coulombic yield는 낙동강, 회동 및 기장의 경우 각각 0.64 C, 0.50 C, 0.61 C로 나타났으며, 농화배양 완료 후의 미생물 군집분포는 ${\beta}$-Proteobacteria, ${\gamma}$-Proteobacteria, Acidobacter 그룹 및 Firmicutes 그룹이 농화배양 전보다 각각 45~90%, 50~90%, 40~80% 및 45~125% 정도 생체량이 증가한 것으로 나타났다. 농화배양이 끝난 후 16S rDNA를 이용한 미생물 동정결과에서, 낙동강 sediment를 주입한 MFC의 경우는 ${\alpha}$-Proteobacteria의 속하는 Roseomonas sp., Azospillum sp.와 ${\gamma}$-Proteobacteria의 Frateuria sp., Dyella sp., Enterobacter sp.와 Deinococci 그룹의 Deinococcus sp.가 동정되었고, 기장 sediment는 ${\alpha}$-Proteobacteria의 Azospillum sp.와 ${\beta}$-Proteobacteria의 Delftia sp., Ralstonia sp.와 ${\gamma}$-Proteobacteria의 Klebsiella sp. 와 Deinococci 그룹의 Deinococcus sp.가 동정되었으며, 회동 sediment는 ${\gamma}$-Proteobacteria의 Pseudomonas sp., Klebsiella sp.와 Deinococci 그룹의 Deinococci sp.와 Actinobacteria 그룹의 Leifsonia sp.와 Bacilli 그룹의 Bacillus sp.가 동정되었다.

• 식물병연구
• /
• 제12권1호
• /
• pp.51-54
• /
• 2006

4종류의 식물 추출 오일(마늘, 생강, 계피, 레몬그라스)에 대한 실내 항균효과를 5종의 식물병원세균과 4종의 식물병원진균에 대해 조사하였다. 4종의 오일중 마늘오일과 계피오일의 항균효과가 우수하였다. 특히, 마늘오일은 식물병원세균인 Agrobacterium tumefaciens, Erwinia carotovora, Ralstonia solanacearum, Xanthomonas campestris와 식물병원진균인 Phytophthora infestans, Fusarium oxysporum, Collectotricum sp.에 대해 강한 항균력을 나타내었다. 그러나, Acidovorax avenae와 Pythium sp.에 대해서는 항균효과가 없었다. 마늘오일의 오이 흰가루병(Sphaerotheca fusca)과 토마토 흰가루병(Erysiphe cichoracearum)에 대한 포장 방제효과 실험결과 각각 70.0-74.6%와 71.2%의 방제가를 나타내었다.

• The Plant Pathology Journal
• /
• 제32권3호
• /
• pp.216-227
• /
• 2016

Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from -2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression.

• Journal of Microbiology and Biotechnology
• /
• 제12권6호
• /
• pp.909-915
• /
• 2002

The biodegradation of BTEX components (benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene) individually and in mixtures was investigated using the o-xylene-degrading thermo-tolerant bacterium Ralsronia sp. strain PHS1 , which utilizes benzene, toluene, ethylbenzene, or o-xylene as its sole carbon source. The results showed that as a single substrate for growth, benzene was superior to both toluene and ethylbenzene. While growth inhibition was severe at higher o-xylene concentrations, no inhibition was observed (up to 100 mg $l^-1$) with ethylbenzene. In mixtures of BTEX compounds, the PHS1 culture was shown to degrade all six BTEX components and the degradation rates were in the order of benzene, toluene, o-xylene, ethylbenzene, and m- and p-xylene. m-Xylene and p-xylene were found to be co-metabolized by this microorganism in the presence of the growth-supporting BTEX compounds. In binary mixtures containing the growth substrates (benzene, toluene, ethylbenzene. and o-xylene), PHS1 degraded each BTEX compound faster when it was alone than when it was a component of a BTEX mixture, although the degree of inhibition varied according to the substrates in the mixtures. p-Xylene was shown to be the most potent inhibitor of BTEX biodegradation in binary mixtures. On the other hand, the degradation rates of the non-growth substrates (m-xylene and p-xylene) were significantly enhanced by the addition of growth substrates. The substrate utilization patterns between PHS1 and other microorganisms were also examined.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
• /
• pp.116-117
• /
• 2001

A thermotolerant bacterium, designated as PHS1, was isolated from a hot spring in Pohang, Korea, on the basis of its ability to grow on BTEX as a sole carbon source. We cloned and sequenced the entire BTEX-degrading pathway genes of PHS1 and found that two multicomponent mono-oxygenases together with meta-pathway genes are responsible for the BTEX biodegradation.

• Journal of Microbiology and Biotechnology
• /
• 제26권10호
• /
• pp.1755-1764
• /
• 2016

The application of Bacillus sp. in the biological control of plant soilborne diseases has been shown to be an environmentally friendly alternative to the use of chemical fungicides. In this study, the effects of bioorganic fertilizer (BOF) fortified with Bacillus amyloliquefaciens SQY 162 on the suppression of tomato bacterial wilt were investigated in pot experiments. The disease incidence of tomato wilt after the application of BOF was 65.18% and 41.62% lower at 10 and 20 days after transplantation, respectively, than in the control condition. BOF also promoted the plant growth. The SQY 162 populations efficiently colonized the tomato rhizosphere, which directly suppressed the number of Ralstonia solanacearum in the tomato rhizosphere soil. In the presence of BOF, the activities of defense-related enzymes in tomato were lower than in the presence of the control treatment, but the expression levels of the defense-related genes of the plants in the salicylic acid and jasmonic acid pathways were enhanced. It was also found that strain SQY 162 could secrete antibiotic surfactin, but not volatile organic compounds, to suppress Ralstonia. The strain could also produce plant growth promotion compounds such as siderophores and indole-3-acetic acid. Thus, owing to its innate multiple-functional traits and its broad biocontrol activities, we found that this antagonistic strain isolated from the tobacco rhizosphere could establish itself successfully in the tomato rhizosphere to control soilborne diseases.

• 한국잠사곤충학회지
• /
• 제44권2호
• /
• pp.64-68
• /
• 2002

본 연구는 곤충 유전자를 이용한 항세균성 펩타이드 생산 및 농업용 소재로서의 응용에 관한 연구로서 항세균성 단백질 누에신 유전자를 베큘로 바이러스 발현계(BEVS)를 이용하여 곤충세포주에서 발현한 후 누에신 단백질의 농업용 소재로서의 가능성을 모색하기 위해 농작물을 가해하는 감자 고추의 무름병을 일으키는 Pectobacterium carotovorum subsp. carotovorum, 가지 및 고추의 풋마름병을 일으키는 Ralstonia solanacearum, 양송이 버섯의 세균성 갈색 무늬 병을 일으키는 Pseudomonas tolaasii 및 무와 배추의 검은썩음병을 일으키는 Xanthomonas campestris pv. campestris 에 대해서 항세균 활성을 관찰하였다. 그 결과 Pectobacterium carotovorum subsp. carotovorum, Ralstonia solanacearum 및 Pseudomonas tolaasii에 대해 높은 활성을 나타내었으며 Xanthomonas campestris pv. campestris에는 활성을 나타내지 않았다. Ion exchange 및 gel filtration chromatography 를 수행하여 약 20 kDa의 성숙 누에신 단백질을 순수 분리하여 pH 및 온도에 대한 안정성을 조사한 결과, pH 2~12 완충액에서 30분간 처리하였을 때에도 항세균 활성이 그대로 유지되었고 10$0^{\circ}C$에서 2시간 처리시에는 활성이 안정되었으며 4시간 처리시에도 80% 정도로 유지됨을 확인함으로써 누에신 단백질은 pH 및 온도에 대한 안정성이 있음을 확인할 수 있었다.