Abstract:

Bacillus mucilaginosus is an usual strain of microbial fertilizer. Main raw materials such as starch, sucrose, glucose, etc. are used in traditional fermentation of biological potassium fertilizer. With corn stalk as raw material, this paper compared fermentation of Bacillus mucilaginosus in starch and sucrose medium and corn stalk enzymatic hydrolysate medium; discussed the feasibility of taking corn stalk enzymatic hydrolysate as carbon source. The results showed that the viable number of 3.52×108 cfu/mL was obtained using corn stalk enzymatic hydrolysate as carbon source, which was 1.63 times of the starch and sucrose culture medium. The result of optimization experiment of corn stalk enzymatic hydrolysate medium showed that the best glucose concentration was 15 g/L and the viable number reached 3.95×108 cfu/mL. The result of 5 L fermenter experiment indicated that viable number reached 6.76×108 cfu/mL under the condition of rotation speed 250 r/min and pH 7.0~7.2, which was 1.71 times of shake flask culture. The results indicated that it was possible that instead of starch or sucrose, corn stalk hydrolysate can ferments Bacillus mucilaginosus, which provides a new way for utilization of corn stalk.

Key words: Bacillus mucilaginosus, corn stalk, viable bacteria number, microbial fertilizer

摘要：

胶质芽胞杆菌WY120是微生物肥料生产常用菌株，传统的生物钾肥菌剂发酵生产的主要原料是采用淀粉、蔗糖和葡萄糖等。以玉米秸秆为原料，通过与淀粉蔗糖培养基发酵培养胶质芽胞杆菌的比较研究，探讨了玉米秸秆酶解液作为碳源发酵生产胶质芽胞杆菌的可行性。结果显示，玉米秸秆酶解液作为碳源发酵生产的胶质芽胞杆菌，其活菌数为3.52×108 cfu/mL，是淀粉蔗糖培养基的1.63倍。秸秆酶解液培养基的优化试验结果显示，其最佳初始葡萄糖浓度为15 g/L，活菌数可达到3.95×108 cfu/mL。当转速为250 r/min，pH控制在7.0~7.2时，5 L发酵罐的试验结果显示，其活菌数高达6.76×108 cfu/mL，是摇瓶培养的1.71倍。研究结果表明，玉米秸秆可替代传统的淀粉蔗糖为碳源发酵生产胶质芽胞杆菌，为玉米秸秆资源化利用提供了一种新途径。

关键词: 胶质芽胞杆菌；玉米秸秆；活菌数；微生物肥料