一株具水霉抑制特性的芽孢杆菌筛选及其分子生物学鉴定

以水霉菌(Saprolegnia ferax)的生物防治为切入点,通过对本实验室保存的9株芽孢杆菌(Bacillus spp.)与水霉菌JL菌株进行对峙拮抗试验,筛选出具有明显抑制水霉菌JL菌株的芽孢杆菌BA1(P<0.05)。经进一步测定菌株BA1对不同来源水霉菌株试验,结果显示菌株BA1对水霉菌株6#、10#、S2也有明显的抑制作用(P<0.05)。通过测定菌株BA1的16 S rDNA,利用BLAST软件进行同源性比对,发现与蜡样芽孢杆菌的同源性在99%以上。由此推测,菌株BA1为蜡样芽孢杆菌菌株,且具有明显抑制水霉菌作用,可以作为水产养殖上水霉病防治的生物制剂使用。

Selection and molecular biological identification of a Bacillus sp.strain to inhibit the growth of Saprolegnia ferax

The present experiment was based on the theory of biological control on Saprolegnia ferax,and the Bacillus sp.strain BA1 to inhibit the growth of S.ferax strain JL significantly was selected by the plate confrontation culture method from 9 stains of B.sp.preserved in the laboratory(P<0.05).And then,the assay of B.sp.strain BA1 to inhibit different resources of S.ferax was conducted.The results indicated that strain BA1 could inhibit the S.ferax stains 6#,10# and S2 significantly(P<0.05).The 16 SrDNA sequences of B.sp.strain BA1was analyzed and compared with other B.sp.in the GenBank on the homolog with BLAST software,the result of alignment with Bacillus cereus showed that the homolog of strain BA1 was more than 99%.So it was speculated that the strain BA1 was B.cereus which could inhibit the growth of S.ferax and probably be used as potential biological control agent to prevent the S.ferax disease in aquaculture.