尖孢镰刀菌拮抗细菌的筛选

报道从土壤中分离到1株对棉花枯萎病致病菌尖孢镰刀菌（Fusrium oxysporum）的菌丝生长及孢子萌发均具有较强拮抗作用的革兰氏阴性细菌J4。并对该菌株进行了形态及部分生理生化鉴定试验。16srRNA序列分析结果表明，该菌株与国际上已报道的溶杆菌属（Lysobacter）中的L．antibioticus细菌的16srRNA序列同源性达到99％。J4菌的培养条件实验结果表明，最佳培养基配方为：葡萄糖10．6g／L，尿素3g／L，NaCl0．5g／L，MgSO4 0．5g／L。在该培养基中J4菌发酵液的抑菌活性最大，J4菌所产生的抗性化合物耐热性较差。

SCREENING AND IDENTIFICATION OF SOME BACTERIAL ISOLATES FOR BIOCONTROLLING WILT DISEASES OF COTTON CAUSED BY FUSRIUM OXYSPORUM

One strain of the gram-negative bacteria named J4 is isolated from soil which showes high antagonistic effects against the mycelium growth of pathogen Fusrium oxysporumf of the cotton disease.Some physiological and morphological experiments have been carried out to identify the J4.The result of 16SrRNA sequencing indicates that the homology between J4 and Lysobacter antibioticus which has been reported before is up to 99%.The experiment result indicateds that the best medium is: Glucose 10.6 g/L,urea 3 g/L,NaCl 0.5 g/L,MgSO4 0.5 g/L.Under this condition the antimicrobial substance in fermentation filtrate of J4 strain is biggest.The thermal stability of resistant compound produced by J4 strain is poor.