枯草芽孢杆菌(Bacillus subtilis)对桑炭疽病菌的抑制作用

以枯草芽孢杆菌(Bacillus subtilis)菌株BS-LX04为材料,测定其对桑炭疽病病原菌(Colletotrichum m orifoli-um)的抑制作用。结果表明BS-LX04对桑炭疸病病原菌的菌丝生长和分生孢子萌发具有较强的拮抗作用:能够使菌丝生长受阻且产生畸形;能够抑制分生孢子的萌发,培养24 h检查孢子萌发抑制率为73.22%;能够推迟分生孢子的萌发时间,并导致萌发孢子的芽管和菌丝畸形而不能继续生长。BS-LX04发酵培养滤液中可粗提到对菌丝生长和分生孢子萌发具有抑制作用的粉状物质,随着菌株培养时间的延长,粗提物对桑炭疽病菌菌丝生长和孢子萌发的抑制率也逐渐升高,即抗菌物质产生逐渐增多,培养48 h是适宜的发酵时间。菌株在28℃培养,获得的抗菌物质粗提物的抑菌率和孢子萌发抑制率均最高,28℃为菌株最适发酵温度。

Inhibition Effect of Bacillus subtilis on Colletotrichum morifolium

The inhibiting effect of BS-LX04,a strain of Bacillus subtilis against Colletotrichum morifolium was examined.The results showed that BS-LX04 had strong antagonistic activity on the mycelia growth and conidia germination.The hyphae were suppressed by BS-LX04 and presented malformation.The conidia germination was inhibited,with an inhibition percentage of 73.22% when examined at 24 h after test.The germination was delayed by BS-LX04 and the germ tube and hyphae also presented malformation though some of the spores germinated and formed hypha.From the culture filtration a powdery crude extraction could be obtained,which contained the antibiotic substance against mycelia growth and conidia germination.The activity of the crude extraction gradually increased with the culture time prolonged and the optimal time was(48 h).The activity changed with the variety of the culture temperature and the optimal was 28 ℃.