一株拮抗酿酒葡萄灰霉病的枯草芽孢杆菌T3筛选、鉴定及抑菌分析

为筛选出对酿酒葡萄灰霉病具有良好抑制作用的拮抗菌,从酿酒葡萄根际土壤进行微生物分离,以灰葡萄孢(Botrytis cinerea)为靶标菌株,采用牛津杯法对拮抗菌进行筛选,通过形态学、生理生化特征以及16S rDNA进行鉴定分析,对拮抗菌进行生长特性及抑菌分析。结果表明:筛选出一株对灰葡萄孢(Botrytis cinerea)具有显著抑制作用的T3菌株,经鉴定为枯草芽孢杆菌(Bacillus subtilis),培养24~48 h T3菌株进入稳定期,最适的生长温度为37 ℃,最适pH为7.0。T3菌株对灰葡萄孢(Botrytis cinerea)MIC为3.6×105 CFU/mL,MBC为3.6×106 CFU/mL,3.6×109 CFU/mL T3菌株对灰葡萄孢(Botrytis cinerea)抑菌直径为31.6±0.2 mm(P<0.05),抑菌效价为158.0±1.0 mm/mL(P<0.05)。扫描电镜观察T3菌株造成灰葡萄孢(Botrytis cinerea)菌丝畸形、扭曲、顶端膨大、原生质收缩、孢子稀松,抑制菌丝生长及孢子萌发。本实验为酿酒葡萄灰霉病的生物防治提供新的微生物资源,具有进一步研究价值。

Screening and Identification of Antagonistic Bacillus subtilis T3 against Wine Grape Gray Mold and Analysis of Its Antimicrobial Activity

In order to screen out the antagonistic bacteria with a good inhibitory effect on grape gray mold,from the root soil of wine grapes,Botrytis cinerea was used as a target strain and the antagonistic bacteria was treated with Oxford cup method. The antagonistic bacterias were identified by morphological,physiological,biochemical characteristics and bacterial 16S rDNA.The antagonistic bacteria growth characteristics and the inhibitory effects of antagonistic bacteria on pathogens were analyzed. The results showed that the T3 strain was screened to have significant inhibition effect on Botrytis cinerea.T3 was identified as Bacillus subtilis and entered a stable phase after being cultured for 24~48 h. The optimal growth temperature of T3 strain was 37 ℃ and its optimal pH was 7.0.The MIC of T3 was 3.6×105 CFU/mL and the MBC was 3.6×106 CFU/mL. The 3.6×109 CFU/mL of T3 strain had a bacteriostatic diameter of 31.6±0.2 mm(P<0.05)against Botrytis cinerea and its bacteriostatic effect price was 158.0±1.0 mm/mL(P<0.05). When observed under the scanning electron microscope,Botrytis cinerea showed mycelium deformity,twisting,apical swelling,protoplast contraction and spores sparsed.T3 strain inhibited mycelial growth and spore germination. It provided the new microbial resource for the biological control of wine grape gray mold and had further research value.