【摘要】 以城市污水处理厂的污泥为原料,探索了微生物转化污泥制备苏云金杆菌生物杀虫剂的可行性,并与常规培养基的发酵进程进行了对比.主要考察了苏云金杆菌的代谢特征、菌体形态与杀虫晶体蛋白产量.研究表明:无需任何预处理工序,污泥所含营养成分即可基本满足苏云金杆菌生长需求,且增殖较快,24h即可达活菌数与活芽孢数的最大值:9.48×108CFU.mL-1和8.51×108CFU.mL-1,比常规培养基提前12h,数量分别提高17%和21%;36h SEM表征显示,污泥中晶体与芽孢大部分游离,且晶体较大,呈规则的菱形,而常规培养基中苏云金杆菌的代谢进程相对滞后,且晶体较小;至发酵终点污泥中杀虫晶体蛋白含量为2.80 mg.mL-1,亦略高于常规培养基.采用污泥发酵制备苏云金杆菌生物杀虫剂大大降低了生产成本,且发酵性能优良,为污泥处置开辟了崭新途径.更多还原

【Abstract】 Feasibility of bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis was studied using sewage sludge as a raw material.The fermentation was also compared with conventional medium.Results showed that without any pretreatment,the nutrients contained in sewage sludge were almost sufficient for Bacillus thuringiensis growth,even with a rapid multiplicational rate.Higher viable cells and viable spores values were obtained earlier at 24 h,with 9.48×10⁸(CFU·mL^-1) and 8.51×10⁸(CFU·mL^-1) respectively,which was 12 hours earlier and nearly 20 percent higher than conventional medium.SEM of 36 h samples gave a clear phenomenon that the metabolizability in sludge was much faster with spores and crystals spreading around.The crystals in sludge seemed rather bigger and more regular.Also a better crystal protein yield of 2.80(mg·mL^-1) was observed in sludge medium compared to conventional medium at the end of fermentation. Sludge fermentation for Bacillus thuringiensis reduces the producing cost,and gives better fermentation capabilities.It’s expected to be a new method for sludge disposal.更多还原