坚强芽孢杆菌的筛选及抗菌活性

Screening and Antifungal Activity of Bacills firmus

采用兰层琼脂法初选对枯斑盘多毛孢Pestalotia funerea有抗生作用的细菌苗株共10株，4株Pseudomonas spp．对枯斑盘多毛孢的抗生作用小于6株Bacillus spp．；在Bacillus spp．中，以B5菌株拮抗带最大，初步鉴定该菌株为芽孢杆菌属的坚强芽孢杆菌Bacillus firmus．对峙培养显示B5对枯斑盘多毛孢有明显的抑菌圈（平均6mm）；B5产生的非挥发性物质对枯斑盘多毛孢菌落的抑制总的表现为稀释度越小，菌落直径生长越小．抑制作用越大，抑制中量为1：1000～1：10000；B5产生的多糖、粗脂肪、蛋白质对枯斑盘多毛孢孢子萌发有抑制作用，粗脂肪可完全抑制枯斑盘多毛孢的孢子萌发（抑制率为100％）．多糖在24h可完全抑制孢于萌发，蛋白质相对较差，48～72h抑制率为85％左右．

10 Bacterial isolates which have antagonism to Pestalotia funerea were primarily obtained by three-layer method. The antagonism of 4 strains of Pseudomonas spp was less than that of the other 6 strains of Bacillus spp. B5, identified as Bacillus firmus. The largest inhibitory zone against Pestalotia funerea was averagely 6 mm after confronting culture, The general inhibitory exhibition of nonvolatile substance from B5 was that the higher the concentration was, the smaller the growth diameter of isolates, and the greater the antibiotic activity （150 ： 1 ： 1 000-1 ： 10 000）. The crude lipids from B5 could absolutely inhibit spore germination （inhibitory rate： 100%） and polysaccharides could absolutely inhibit it in 24 h （inhibitory rate; about 85%）. Both of them were better than proteins.