土壤拮抗链霉菌R15菌株发酵产物的抑菌作用

对一株土壤拮抗链霉菌（Streptomyce spp.）R15菌株发酵液的抑菌效果、热稳定性和酸碱稳定性以及作用机制进行了初步研究。结果表明，拮抗链霉菌R15发酵液对棉花枯萎病菌分生孢子萌发抑制作用强，抑制率达98.37%。烟草赤星病菌孢子萌发后芽管顶端膨大成球形，芽管停止生长；烟草炭疽病菌孢子萌发后不能产生附着胞，且芽管顶端有突起。处理烟草黑胫病菌和辣椒疫霉病菌菌丝畸变、扭曲、菌丝壁消解；R15通过菌丝缠绕、穿透、紧贴的方式重寄生于烟草黑胫病菌菌丝上，致使菌丝断裂。链霉菌R15发酵液的热稳定性和酸碱稳定性较强，在20~55℃，pH3~9范围内都具有抑菌活性。

Inhibition of the Metabolite of Antifungal Soil Streptomyce spp. R15

The inhibitive effect, thermostability, pH stability and action mechanism of the metabolite of Streptomyce spp. R15 were primarily studied. The results showed that the metabolite of R15 exhibit strong inhibition on the spores germination of Fusarium oxysporum f.sp. vasinfectum, inhibition rate was 98.37%. The germ tubes of spores of the Alternaria alternate were swollen then stopped growing after treated with the metabolite; the conidia of Colletotrichum nicotianae could germinate but not form appressoria, the germ tubes formed apophysises in their top end. The hypha of P. parasitica and P. capsici were aberrance, twisted and cell wall was disintegrated. By means of twisting, penetrating and clinging, R15 hyperparasited on the hypha of the P. parasitica, the hypha of P. parasitica was broken. The metabolite was stable with heat and pH. The metabolite had better inhibitive effect when it was at temperature 20~55℃, pH 3~9.