葡萄白腐病拮抗链霉菌G4的筛选、鉴定及发酵条件的优化

从长春市葡萄园采集的9份土样中分离出放线菌菌株70株,采用平板对峙法初筛到了对葡萄白腐病菌(Coplodiella diplodiella)有较好拮抗作用的放线菌菌株7株,采用琼脂扩散法复筛出拮抗作用最好的菌株G4.对G4菌株的发酵液进行了抗菌谱测定,结果表明发酵液对番茄叶霉病菌(Fulvia fulva)、禾谷镰孢菌(Fusarium graminearum)等其他8种植物病原真菌都有拮抗作用,对葡萄白腐病菌的拮抗作用最好,抑菌圈直径达26.5 mm.通过对菌株G4的形态特征、培养特征、生理生化反应和16S rDNA鉴定该菌株为淡紫灰链霉菌(Streptomyces lavendulae).通过发酵条件优化,确定了菌株G4的最佳发酵条件:玉米粉60 g/L,葡萄糖30 g/L,大豆粉60 g/L,硝酸钾5 g/L,磷酸二氢钾1g/L,碳酸钙3g/L,氯化钠1g/L,pH为自然,种龄22 h,装瓶量40 mL/250 mL,接种量4％,发酵温度28℃,转速200 r/min,发酵时间48 h.

Optimization of Screening, Identification and Fermentation Conditions of Streptomyces Strain G4 Antagonistic against Coniella diplodiella

Seven actinomycetes strains antagonistic against Coniella diplodiella were obtained from 9 soil samples collected from the grape garden in Changchun city in the experiment,of which strain G4 had the best inhibitory effect.Antifungal spectrum of fermentation liquid from strain G4 was determined by agar diffusion method.The results showed that the fermentation liquid had better inhibitory effects against nine common plant pathogenic fungi,the best inhibitory effect was against Coniella diplodiella,and the diameter of inhibition ring was 26.5 millimeters.The results on morphological,cultural,physio-biochemical characteristics and 16S rDNA sequence alignment revealed that strain G4 belonged to Streptomyces lavendulae.The optimal fermentation conditions of strain G4 consisted of corn powder 60 g/L,dextrose 30 g/L,soybean powder 60 g/L,KNO3 5 g/L,KH2PO4 1 g/L,CaCO3 3 g/L,NaCl 1 g/L,pH nature,inoculation age 22 h,adding quantity 40 mL/250 mL,inoculation quantity 4%,temperature 28℃,shaking speed 200 r/min and time 48 h.