摘要
富营养化湖泊中蓝藻爆发已成突出的环境问题。以云南昆明滇池蓝藻新鲜藻泥为培养基,通过接种Bt菌种,测定发酵过程中Bt的活菌数及芽胞数,观察其生长过程中形态变化,同时测定杀虫晶体蛋白产量及杀虫毒力效价,并与常规LB培养基比较,探究了利用蓝藻藻泥培养基接种苏云金芽胞杆菌(Bt GIM1.32)制备生物源杀虫剂的可行性。结果表明:Bt GIM1.32菌种在新鲜蓝藻培养基中能正常生长并完成芽胞和伴胞晶体的合成;当蓝藻含固率为3%、pH 7、接种活化10 h处于对数生长期的菌种、接种量为2%、培养温度为30℃时,灭菌后直接接种Bt GIM1.32菌株,发酵48 h左右其活菌数可达到相对稳定值(6.79×108CFU/mL),54 h左右芽胞数达到相对稳定值(7.01×108CFU/mL);其130 ku晶体蛋白的质量浓度为4.81 mg/mL,对3龄小菜蛾的致死中浓度(LC50)为0.180μL/mL,毒力效价为1 600.00 IU/μL;发酵性能较常规LB培养基优良。研究表明,蓝藻作为发酵生产生物源农药Bt的培养基具有很好的开发潜力和应用前景。
Blooms of blue-green algae in eutrophication lake has been one of the major environmental problems in recent years. Bioconversion of blue-green algae to biopesticide by Bacillus thuringiensis GIMI. 32 was studied using the mud of blue-green algae in Dianchi lake of Yunnan province as culture medium. During fermentation, the available cells and spores, as well as the morphology and metabolic characteristics of B. thuringiensis GIM1.32 were measured. Furthermore, the production of insecticidal crystal protein and its toxicity titer of B. thuringiensis GIMI. 32 in the mud of blue-green algae were also investigated, comparing with that in the conventional LB culture medium. The results showed that the mud of blue-green algae was a suitable medium for B. thuringiensis GIM1.32, in which the growth, spore formation and spore crystal synthesis of B. thuringiensis GIM1.32 were normal. When the mud of blue-green algae （3 % solid content and pH of 7 ） was sterilized and inoculated with pre- cultured （ 10 h） B. thuringiensis GIM1.32, with inoculation level as 2%, and cultured at 30 ℃, theavailable B. thuringiensis GIM1.32 reached 6.79 ×10^8 CFU/mL and kept relatively stable after 48 h, moreover, the number of spores reached a relatively stable value around 7.01×10^8 CFU/mL after 54 h. The concentration of 130 ku crystal protein was 4. 81 mg/mL, the LC50 value to Plutella xylostella was 0. 180 μL/mL, and the toxic titer was 1 600.00 IU/μL. Which were superior to those in the ordinary LB culture medium. The results of present study suggested that blue-green algae has good potential application prospect as medium to produce biopesticide in the future.
出处
《农药学学报》
CAS
CSCD
北大核心
2014年第1期41-48,共8页
Chinese Journal of Pesticide Science
基金
云南省社会发展科技计划项目(2012CA017)
关键词
蓝藻
苏云金芽胞杆菌
生物源杀虫剂
blue-green algae
Bacillus thuringiensis Berliner
biopesticide
