양파 근권미생물은 양파 뿌리를 균원시료로 하여 약 250여종의 근권미생물을 순수 분리하였고 이들 중에서 길항미생물은 무름병균인 Erwinia carotovora subsp. carotovora와 시들음병균인 Fuarium oxysporium에 각각 서로 대치 배양하여 두 병원균 모두에 가장 강한 길항 효과를 나타내는 YJ-4 균주를 최종 선발하였다. 선발균주 YJ-4는 Bergey's mannual of systematic bacteriology
This study was carried out to isolate of antagonistic bacterium to Allium cepa L. pathogens. A total of 250 strains were isolated from A. cepa L. roots. The isolates were screened for antagonism to A. cepa L. pathogens and the isolated strain No. YJ-4 was selected among these bacteria. It was identified as Bacillus ehimensis based on morphological and physiological characteristics according to the Bergey's mannual of systematic bacteriology, Sherlock system of Microbial ID Int and 165 rDNA sequences methods. Bacillus ehimensis YJ-4 showed broad spectrum of antibacterial and antifungal activities against plant pathogens as Alternaria porri, Botrytis cinerea, Erwinia carotovora subsp. carotovora Fusarium of oxysporium, penicillium sp., Pseudomonas sp., Rhizoctonia solani, Sclerotium cepivotum, Septoria sp., Stemphylium botryosum. Speially B. ehimensis YJ-4 showed high antifungal activity on growth against F. oxysporium, the causal agent of onion Fusarium wilt.