产几丁质酶放线菌的筛选、鉴定及其对草坪草根腐病真菌的抑制作用

Screening and Identification of Chitinolytic Actinomycetes and the Inhibitory Activity on Turfgrass Root Rot Disease Fungi

通过对草坪土壤中产几丁质酶放线菌的筛选、鉴定及对4种草坪草根腐病菌的抑制作用研究,为草坪草根腐病的生物防治提供指导。通过菌落法和菌饼法筛选得到1株产几丁质酶活性较强的放线菌菌株Bn035,其降解圈相对直径分别为3.60和3.42;采用DNS法测量几丁质酶活性发现,第6 d时酶活达到最大为1.23 U·mL^(-1);菌体和粗酶液均对草坪草根腐病菌产生较强的抑制作用;根据形态学特征、培养特征、生理生化特征和16S rDNA序列比对综合分析,菌株Bn035为皱孢链霉菌(Streptomyces scabrisporus)。菌株Bn035产几丁质酶活性较强且抑菌效果较好,表明其在真菌性根腐病生物防治方面具有潜力。

Chitinolytic actinomycetes from lawn soil were screened and identified and their inhibitory activi- ties on four types of turfgrass root rot disease were studied. Results showed that screened Bn035 strain had stronger chitinase activity than the other four strains; the relative diameter of chitin-lytic zone was 3.60 and 3.42, respectively. Its chitinase activity in culture broth reached a maximum value of 1.23 U ·mL^-1 on the 6th day. Crude enzyme solution and thallus of Bn035 strain showed stronger antifungal activity a- gainst all tested fungi. The Bn035 strain was identified as Streptomyces scabrisporus by morphological, cultural, physiological, biochemical and phylogenetic characteristics. The Bn035 strain had strong chiti- nase activity and inhibitory activity that suggested its potential application in the biological control of turf- grass fungal root rot disease.