继代培养对球孢白僵菌毒素产生水平的影响

Influence on the Toxin Production Level of Beauveria bassiana During Subculturing

继代培养对球孢白僵菌生物学特性、毒力及毒力相关因素等均会产生影响,研究了继代培养对球孢白僵菌毒素产生水平的影响。对野生球孢白僵菌D6-2和L1-1菌株进行室内培养基继代培养,利用高效液相色谱(HPLC)法对其代谢产物中已报道的2种毒素2-氯杀鼠灵酮和间甲基苯甲酸甲酯在不同世代的代谢水平进行了检测。对2株供试球孢白僵菌菌株,收集不同世代在SDAY培养基中培养相同时间后等量的白僵菌培养液,经过有机溶剂提取脂溶性部分,经HPLC定量检测,2个供试菌株各世代培养液中均只有F1代代谢产物中检测出了2-氯杀鼠灵酮,而F2—F5代未检测到,并且供试菌株各世代代谢产物中均未检测到间甲基苯甲酸甲酯;并且发现在继代培养过程中,有未知化合物产生水平未随着世代增加而发生显著变化。不同白僵菌菌株毒素的代谢种类存在差异,并且继代培养会降低某些毒素的代谢水平,也许是继代培养导致供试菌株毒力下降的原因之一;对于其他种类白僵菌毒素在继代培养过程中的代谢水平需进一步研究。

The biological character, toxicity and toxicity relative factors of Beauveria bassiana were influenced by subculturing, the effect on toxin production level of subculturing was investigated in this research. The B. bassiana strains D6-2 and LI-1 were subcultured on SDAY medium, to detect the influence of subculturing on production level at different generations of toxin methyl 3-methylbenzoate and 2-Coumaranone, by high performance liquid chromatography （HPLC） method. The inoculum at the same culturing time of different B. bassiana generations was collected, and its liposolubility portion was extracted by ethylaleohol and ethyl acetate sequentially, it showed via HPLC detection that 2-Coumaranone was detected in metabolic product of two strains F1 generation, but not in that of F2-F5 generations, and there was no methyl 3-methylbenzoate detected in all samples of the two strains. However, there was other unknown product of metabolism was detected, and established a relative stable expression level in subculturing. There was difference on toxin species of different strains of B. bassiana, and subcuhuring was able to lower the production level of some toxin, it was possible one of the reasons of toxicity decline. It needed further research for the other species of toxin expression level in different subeulturing generations.