2种拟青霉代谢产物对烟蚜乙酰胆碱酯酶和羧酸酯酶的影响

 以粉拟青霉菌的sw03032菌株和玫烟色拟青霉菌的sw03085为研究对象,比较其代谢产物的杀蚜虫活性和对烟蚜乙酰胆碱脂酶和羧酸酯酶活性的影响.结果表明2种真菌发酵液含有能毒杀蚜虫的毒素物质.且毒素粗提物浓度越大,杀蚜活性越强.经玫烟色拟青霉菌不同浓度毒素粗提液处理的蚜虫乙酰胆碱酯酶比活力分别比对照(CK2)降低了70.4%～29.8%.不同浓度玫烟色拟青霉菌毒素粗提液处理12h后,蚜虫羧酸酯酶比活力分别比对照(CK2)降低79.5%～44.4%.用不同浓度粉拟青霉菌毒素粗提液处理烟蚜12h后,乙酰胆碱酯酶和酸酸酯酶活性分别降低了38%～18.6%和51.6%～59.5%.玫烟色拟青霉菌的sw03085菌株代谢产物对烟蚜的伤害活性明显较粉拟青霉菌sw03032菌株代谢产物高.     

胆固醇氧化酶高产菌株的诱变选育及产酶条件优化

在对细脚拟青霉、玫烟色拟青霉、粉拟青霉、香菇、平菇、金针菇等胆固醇氧化酶产生菌初筛的基础上,选择以产酶较高的玫烟色拟青霉作为紫外诱变的出发菌株,筛选出一株相对高产突变菌株MFEC006,其酶活达到了0.548 3 U/mL,比出发菌株提高了154%,经8次传代培养,突变株性质稳定.对MFEC006菌株产酶条件进行优化,得出其最佳产酶条件为:pH为6.5.温度27℃,接种量10%,摇床转速180 r/min.     

Ovicidal activity of two fungal pathogens （Hyphomycetes）against Tetranychus cinnabarinus （Acarina：Tetranichidae）

The carmine spider mite, Tetranychus cinna-barinus, is an economically important pest that devastates varieties of crops worldwide and develops significant resistance to common chemical pesticides, most of which lack ovicidal activity. In the present study, two isolates of entomopathogenic fungi, Beuaveria bassiana SG8702 and Pae-cilomyces fumosoroseus Pfrl53, were bioassayed against T. cinnabarinus eggs at 25 ℃ under a photophase of 12 : 12 (L:D). Infected eggs on Vicia faba var. minor leaves failed to hatch due to distortion and shrinkage and had fungal outgrowths when maintained under moist conditions. Sprays of B. bassiana conidia to T. cinnabarinus eggs (on leaves) at the concentrations of 58, 298 and 1306 conidia/mm2 (3 replicates per concentration and 35-65 fresh mite eggs per replicate) resulted in corrected egg mortalities of 20.4±4.2%, 36.0±7.6% and 64.6±12.5% (F=43.14, P <0.01), respectively; sprays of P. fumosoroseus at 129, 402 and 2328 conidia/mm2 caused egg mortalities of 16.1±11.1%,