拮抗放线菌的筛选培养基与筛选方法研究

Study on the media and methods of selecting antimicrobial actinomycetes

从黄土高原人工植被土壤中分离得到若干放线菌,研究了从中筛选的50株拮抗性放线菌在不同培养基上对8种供试靶标菌的拮抗性。结果表明:1在黄豆粉琼脂和玉米粉琼脂培养基上,放线菌生长较好,在PDA和高氏1号琼脂培养基上生长次之。玉米粉和黄豆粉琼脂均可作为拮抗性放线菌的筛选培养基。2反向放置琼脂块是筛选拮抗性放线菌的一种有效且可靠的方法。3筛选拮抗性放线菌时,制备琼脂块的培养时间应控制在8～12d,培养时间过长将会导致拮抗作用减弱。4筛选得到的50株供试放线菌中对辣椒疫霉、黄瓜枯萎菌、棉花枯萎菌、西瓜枯萎菌、青霉、假丝酵母、金黄色葡萄球菌及大肠杆菌有拮抗性的放线菌株数分别为27,26,33,36,35,29,35和20株。

Antimicrobial experiment on fifty strains on antimicrobial actinomycete against bacteria and fungi was carried out,and the results showed that:① Actinomycete grew better on the media of soybean farina agar and cornmeal agar than that of PDA and gauze No.1 (GA).Both media of soybean farina agar and cornmeal agar were used to select antimicrobial actinomycetes.② Laying the agar block on the medium reversedly was a kind of effective and dependable way to select antimicrobial actinomycetes.③ The control time of cultivation of antinomycetes was usually within 8-12 days as we prepare for agar to select antimicrobial actinomycetes.Too long time would reduce antimicrobial effect of actinomycete against bacteria and fungi.④ There were 27,26,33,36,35,29,35 and 20 strains of actinomycetes antimicrobial against Phytophthoracapsici,Fusarium oxysporium f.sp cucumerinum,F.f.sp vasinfectum,F.f.sp niveum,Penicillium sp,Candida tropicalis,Staphalococcus aureus,Escherichia coli,respectively,in fifty strains of actinomycete,which were isolated from the soil of artificially vegetation of Loess Plateau.