Abstract:

Antigonistic bacterium BAB-1 was isolated from soil and showed potential for controlling tomato grey mold. Strain BAB-1 was identified as Bacillus subtilis according to its morphological characteristics, 16S rDNA sequence and the result of API 50CHB system. 16 different media for the bacterial growth and production of antifungal substrates were tested. Results showed that the medium No.3 was suitable for either bacterial growth or antifungal substrates producing. Optimum fermentation conditions for bacterial growth were as following: temperature 30℃, 210 rpm, pH 7.24, inoculation amount 3% and amount of loading 70 mL/250 mL flask. Under these conditions, the cell density could reach 1.63×109 cfu/mL. While the optimum conditions for antifungal substance producing were temperature 30℃, 210 rpm, pH 7.24, inoculation amount 2% and amount of loading 100 mL/250 mL flask. Under these conditions, the inhibition zone of strain BAB-1 against Botrytis cinerea could reach 1.81cm width.

Key words: Botrytis cinerea, Bacillus subtilis, ideutification, media optimization, biocontrol bacterial strain BAB-1

摘要：

菌株BAB-1是从土壤中分离出的对番茄灰霉病具有较好防治效果的拮抗细菌。通过对该菌株进行形态特征观察、16S rDNA序列分析和API 50CHB细菌鉴定试剂盒鉴定，确定菌株BAB1为枯草芽孢杆菌（Bacillus subtilis）。采用16种培养基对菌株BAB-1进行了发酵培养，结果表明，3号培养基最适合该菌株菌体生长和抑菌物质的产生。进一步进行了培养条件的优化，发现在培养温度30℃，转速210 rpm，初始pH 7.24，接种量3%，装样量为70 mL/250 mL时菌体生产量最高，菌量达到1.63×109 cfu/mL；而在培养温度30℃，转速210 rpm，初始pH 7.24，接种量2%，装样量为100 mL/250 mL时最适合抑菌物质的产生，对番茄灰霉病菌的抑菌圈直径达到1.81 cm。

关键词: 灰霉病菌；枯草芽孢杆菌；鉴定；培养基优化；生防细菌BAB-1