两步培养法测定真菌产孢营养需求(英文)

Fungal sporulation in two-stage cultivation

生防真菌产孢条件的测定一般都是通过连续培养方法,即在同一种限定培养基上完成其生长和产孢过程。文中我们提出分离真菌的生长和产孢阶段,测定产孢营养需求的两步培养新方法。6种生防真菌首先在平板上进行营养生长,然后转移至营养成分和浓度确定的新鲜培养基中继续产孢过程来测定菌株产孢阶段实际营养需求。通过与连续培养方法比较,发现只有淡紫拟青霉Paecilomyces lilacinus、金龟子绿僵菌Metarhizium anisopliae二者产孢条件一致,而厚孢轮枝菌Pochonia chlamydosporia、球孢白僵菌Beauveria bassiana、蜡蚧轮枝菌Lecanicillium lecanii、绿色木霉Trichoderma viride菌株产孢的营养条件存在显著的差异。基于这一方法,确定了绿色木霉最佳产孢条件,即起始碳浓度2gC/L,碳氮比10:1,最佳碳氮源组合纤维二糖和酵母浸膏,为真菌生防制剂生产调控提供了依据。

Fungal sporulation is separated from its vegetative growth. In this paper a novel two-stage cultivation method is described to determine fungal nutrition requirements for maximizing spore production. In this method, the fungus is first cultured on agar to grow vegetatively for 4d, and then transferred to a new nutritionally defined medium, where it sporulates for 4d. The effects of media nutrients on spore production were compared using the new method vs. traditional continuous cultivation for six fungi with biological control potential Paecilomyces lilacinus, Pochonia chlamydosporia, Beauveria bassiana, Metarhizium anisopliae, Lecanicilliurn lecanii, and Trichoderma viride. The two methods did not differ for P. lilacinus or M. anisopliae but differ for the other fungi. In particular, B. bassiana and P chlamydosporia required different nutrients to produce large numbers of spores with continuous vs. two-stage cultivation. Spore production by L. lecanii differed greatly between the two cultivation methods when sucrose and yeast extract were as carbon and nitrogen sources, respectively. It was revealed yeast extract supported abundant sporulation of T. viride by two-stage cultivation. Based on the new method, T. viride produced the most spores when the medium contained 2g carbon/L, C：N=10：1, and cellobiose/yeast as the carbon/nitrogen sources.