重庆低海拔虫草无性型分离纯化及其生长条件研究

Anamorph Isolation of a Genus Cordyceps in Low Altitude Area in Chongqing and Its Growth Condition Research

从重庆低海拔地区采得一株虫草,命名为重庆虫草(Cordyceps chongqingensis Zhenget al)。采用子囊孢子、内菌核和子座的多途径分离法,获得同一种菌。并且该无性型菌株在实验室加富米饭培养基上培养,自然条件下约1.5月开始长出白色子座。同时,以菌丝干重为指标,考核了不同碳源、氮源、发酵温度、培养基初始pH等因素对菌丝量的影响,筛选出摇瓶生长培养基为:NaNO30.2%,K2HPO40.1%,KCl 0.05%,MgSO4.7H2O0.05%,FeSO40.001%,蔗糖3.0%,蚕蛹粉0.5%,豆饼粉0.5%。采用正交实验确定了虫草菌的最佳生长条件为:pH5.0,温度28℃,转速200 rpm。在此优化条件下,其菌丝量在第7 d达最大值,即35.6 g/L。

A species of Cordyceps was collected from low altitude area in Chongqing which was named Cordyceps chongqingensis Zheng et al. Its anamorph was isolated with more ways on its ascospore, sclerotium, stroma. And it was cultured on rich rice medium and white stroma obtained on that medium after one and half months. Effects of different carbon sources, nitrogen sources, fermentation temperatures, medium pH et al on dry weight of mycelia were studied. The compounding of growth medium was NaNO3 0. 2%, K2HPO4 0. 1%, KC1 0. 05%, MgSO4· 7H2O 0.05%, FeSO4 0. 001%, sugar 3.0%, silkworm chrysalis flour 0.5 %, soybean flour 0.5 %. And the growth conditions were studied by orthogonal tests, the best conditions included： temperature 28 ℃ ,pH 5.0, rotation speed 200 rpm. Under these optimal conditions,the maximum of dry weight of mycelia was obtained at 7^th day that was 35.6 g/L.