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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。
Blue eutrophication in eutrophic lakes has become a prominent environmental problem. The cyanobacterial fresh algae mud of Dianchi Lake in Kunming, Yunnan was used as culture medium. Through inoculation of Bt strains, the number of viable cells and the number of spores of Bt in the fermentation process were determined, and the morphological changes during growth were observed. Meanwhile, the production of insecticidal crystal protein and insecticidal toxicity Titers and potency. Compared with the conventional LB medium, the feasibility of preparing the biogenic insecticide by inoculating Bacillus thuringiensis (Bt GIM1.32) with cyanobacterial culture medium was explored. The results showed that the strain Bt GIM1.32 can grow normally in fresh cyanobacteria medium and complete the synthesis of spores and companion crystals. When the cyanobacteria solid content is 3%, pH 7, and inoculated for 10 h in logarithmic growth phase The strain Bt GIM1.32 was inoculated directly after sterilization at 2% inoculum at a culture temperature of 30 ℃. The viable count reached 6.79 × 108CFU / mL after 48 h of fermentation, (7.01 × 108 CFU / mL), the mass concentration of 130 ku crystal protein was 4.81 mg / mL, and the LC50 of 3rd instar Plutella xylostella was 0.180 μL / mL. The virulence Price of 1 600.00 IU / μL; fermentation performance than conventional LB medium excellent. Studies have shown that cyanobacteria fermentation medium for the production of bio-pesticides Bt has good development potential and application prospects.