摘要
用同步培养和异步培养从91株大气腐生菌中筛选出13株对9种植物病原细菌有抑制作用的拮抗菌株,其中Bacillus cereus G35菌株的去菌上清液经硫酸铵沉淀、透析去盐、Sephadex G-50凝胶过滤,所得分段收集液对280nm有两个明显的吸收峰,抑菌活性与第二吸收峰吻合,对蛋白酶E和蛋白酶K敏感,对100℃温度处理10min和酚抽提处理敏感,对胰蛋白酶部分敏感,对核糖核酸酶及温度60℃,80℃ 30min处理稳定,其活性物质提取量在一定范围内随硫酸铵饱和度提高而增大。培养基种类、温度、培养时间对该菌株产生拮抗物有不同程度影响,在KMB培养液中30℃振荡培养18h后,拮抗物产生达到稳定,紫外线处理能促进洁抗物产生。此外,还报道了有关B.cereus G35变异株G35-M的某些研究结果。
Thirteen strains which inhibit nine phytopathogenic bacterial Strains were screened from ninty-one atmospheric saprophytic bacteria by the simultaneous and modified deferred antagonism procedures. One plasmid harboring strain, Bacillus cereus G35, was further studied. The inhibiting agent partially purified from supernatant of G35 culture by ammonium sulphate precipitation and Sephadex G-50 filtration was sensitive to pronase E, proteinase K, phenol and 100℃ for 10 min., partially sensitive to trypsin and resistant to RNase, and treatments of 60 ℃ and 80℃G for 30 min.. The fractional collection had two absorption peaks at 280 nm, the second one coincided with its anti-bacteria activity. Yield of antagonist was affected by medium, temperature, culturing time and could be stimulated with UV light, in KMB liquid medium at 30℃ for 18 hrs, maximum yield would be reached. Other results about the plasmids-free mutant G35-M were also reported.
关键词
植物
病原细菌
拮抗菌
测定
plants
pathogenetic microbe
antagonistic bacteria
Bacillus cereus
bacterial strains
determination
