顶孢霉菌(Acremonium hansfordii)液体培养最适条件及杀蚜毒力的研究

Study on optimal condition in liquid culture and toxicity of Acremonium hansfordii to Brevicoryne brassicae

对自然感病的桃蚜幼虫上获得的顶孢霉菌株(Acremonium hansfordii)的最适培养条件及对甘蓝蚜的致病力进行了研究.结果表明,顶孢霉菌生长和产孢的最佳碳源为木糖,菌丝生物量和产孢量分别为1.806 mg/mL和7.061×106个孢子/mL;最佳氮源为尿素,其菌丝体含量和产孢量分别为0.242 mg/mL和54.07×106个孢子/mL;最适于顶孢霉菌菌丝生长和产孢的C/N为10∶1.液体培养至6-7 d时,菌丝生物量和产孢量均达到高峰,因此液体发酵终止时间应选择在接种后6-7 d.在接种后的第6 d,顶孢霉菌对甘蓝蚜的LC50为1.650×106个孢子/mL.

The fungi Acremonium hansfordii was isolated and purified from Myzus persicae. The optimal condition in liquid culture and the toxicity of Acremonium hansfordii to Brevicoryne brassicae were studied. The results indicated that the optimal C-source for mycelium growth and conidia yields of Acremonium hansfordii was xylose. The mycelia biomass and the conidia yield were 1.806 mg/mL and 7.061×10^6 conidia/mL respectively. The optimal N-source was nitrogen. The mycelia biomass and the conidia yield were 0. 242 mg/mL and 54.07 ×10^6 conidia/mL respectively. The optimal ratio of C-source to N-source was 10 ： 1. The mycelia biomass and conidia yield of Acremonium hansfordii reached the peak in 6 to 7 days. Therefore,6 to 7 days was the best inoculation time as the terminal of liquid fermentation. After 6 days inoculation,the LC50 of Acremonium hansfordii to Brevicoryne brassicae was 1. 650×10^6 conidia/mL.