一株拮抗芒果炭疽菌海洋细菌的鉴定和发酵培养基优化

Identification and Fermentation medium Optimization of Marine Bacteria BSW03 Against Colletotrichum gloeosporioides Causing Mango Anthracnose

从湛江近海海水和海泥分离的229株细菌中,选出对芒果炭疽菌(Colletotrichum gloeosporioides)具有较强拮抗作用的海洋细菌BSW03,抑菌圈直径为14.0 mm。根据菌体形态、生理生化特性和16s rDNA序列分析,BSW03鉴定为枯草芽孢杆菌(Bacillus subtilis)。从9种培养基中筛选出BDPB作为BSW03的发酵培养基,通过单因子碳源、氮源试验和L9(34)正交试验对发酵培养基成分进行优化。结果表明:发酵培养基最佳配方为乳糖20 g/L,牛肉膏15 g/L,K2HPO3.3H2O 0.75 g/L,MgSO4 0.75 g/L,pH自然。转速170 r/min、温度28℃的恒温摇床培养3 d后的无菌发酵液抑菌效果最佳,抑菌圈直径为27.3 mm。

The marine bacterium strain BSW03,which antagonized against Colletotrichum gloeosporioides causing mango anthracnose,were screened from two hundreds and twenty-nine strains of marine bacteria isolated from offshore sea water and mud in Zhanjiang.The inhibiting width of isolate BSW03 reached 14.0 mm.Strain BSW03 was defined as Bacillus subtilis according to the characteristics of morphology,physio-biochemical reactions and 16s rDNA sequences analysis.The BDPB medium was singled out as the ferment initial medium of BSW03.The ingredients of initial medium were optimized by the monofactorial nitrogen source,carbon source experiment and L9（34） Latin orthogonal experiments,the results showed that the optimal medium ingredients were comprised of lactose 20g/L,beef extract 15g/L,K2HPO33H2O 0.75g/L,MgSO4 0.75g/L.The diameter of inhibition halo of cell-free fermental liquor was 27.3mm after BSW03 was inoculated in 50ml flasks with 20ml optimal medium,and incubated in shaker with rotate speed of 170 r/min on 28℃ for three days.