利用玉米浸泡液制备苏云金杆菌生物杀虫剂  

Production of Bacillus thuringiensis biopesticide using corn steepwater as raw material

作　　者：卢娜[1] 周顺桂[1] 常明[1] 倪晋仁[1] 

机构地区：[1]北京大学环境工程系教育部水沙科学重点实验室,北京100871

出　　处：《环境科学学报》2007年第12期1978-1983,共6页Acta Scientiae Circumstantiae

基　　金：广东省自然科学基金(No5006694);广东省科技攻关项目(No2005B10401008)~~

摘　　要：以玉米淀粉生产过程中的浸泡液作为原料培养基,在5L发酵罐中培养苏云金杆菌生物杀虫剂,并以常规黄豆粉培养基为对照,考察了苏云金杆菌在玉米浸泡液中的生长代谢状况(包括菌体形态、菌数增长与芽孢形成)以及48h发酵液的生物毒效.研究表明,无需添加其它成分及前处理,玉米浸泡液所含营养成分即可满足苏云金杆菌生长需求,其培养的总活菌数及芽孢数在27h可达最大值1.51×109CFU.mL-1和1.41×109CFU.mL-1,分别比常规培养基高出59%和85%,芽孢形成与晶体释放提前约9～12h;36h扫描电镜(SEM)观察表明,发酵36h浸泡液中大部分芽孢囊已经自溶,游离出卵圆形芽孢与菱形的晶体;而此时常规培养基正处于芽孢形成后期,只有极少数的游离晶体与芽孢;48h发酵终点的生物毒效结果显示,以浸泡液为培养基的苏云金杆菌发酵液毒效(891.51IU.μL-1)比常规培养基高89%.本试验为浸泡液的再利用提供了一条崭新的途径,同时降低了杀虫剂的生产成本.In the Bacillus thuringiensis toxin production process, the choice of raw materials greatly affects the biopesticide cost. In this study, corn steepwater was used as a raw material to produce Bacillus thuringiensis biopesticide in a 5L fermentor, with conventional soybean meal based medium as the control. Metabolic parameters including viable cell growth, sporulation and entomotoxicity were evaluated. The results showed that the nutrients contained in corn steepwater were sufficient for Bacillus thuringiensis growth without any pretreatment. In corn steepwater, maximum counts of viable cells, 1.51 × 10^9 CFU·mL^-1 , and viable spores, 1.41×10^9 CFU·mL^-1 , were obtained at 27 h, which were 59% and 85% higher than those in the control. The fermentation cycle could be shortened by 9 - 12 hours compared to the conventional medium. Scanning electron microscope （SEM） observations showed that most of crystals with typical bipyamidal shapes were released in corn steepwater during 36 h of cultivation, while in the conventional medium the sporangia began to autolyse at the same time. At the end of the fermentation （48 h）, an entomotoxicity of 891.51 IU·μL^-1 was observed in corn steepwater, 89% higher than that in the conventional medium. Therefore, corn steepwater is a fine medium for Bacillus thuringiensis production. This study provides novel solutions for safe disposal of corn steepwater and simultaneous production of high potency and low cost biopestieide.

关 键 词：玉米浸泡液 苏云金芽孢杆菌 生物杀虫剂 生物毒效 

分 类 号：X172[环境科学与工程—环境科学]