关键词: 胶质芽胞杆菌；固体发酵；分类鉴定；正交试验；单因素实验

Abstract:

Bacillus mucilaginosus is a kind of heterotrophic aerobic bacteria, which can decompose phosphorus and potassium in soil and silicate minerals, and is widely used in microbial fertilizers. The bacteria is cultured by liquid fermentation and followed by peat adsorption, but the effective number of viable microorganisms and spore rate were lower. Therefore, it is important to identify how to increase the number of viable cells and spore rate with optimized fermentation pattern and condition of Bacillus mucilaginosus. In this study, a strain named YA\|07 was isolated from apple orchard soil in Luochuan County of Shannxi Province, which was identified as Bacillus Mucilaginosus through the morphological, physiological and biochemical experiments and the sequence of 16s rDNA. By single factor, and orthogonal experiments, a kind of solid\|state fermentation condition, which could produce high density of effective living bacterium and high rate of spore was established. The Results showed that the medium that can make YA\|07 produce a large number of effective number of living bacterium, and high spore rate can be divided into 500 mL bottles of peat 50 g, starch 3%, peptone 3%, without inorganic salts and trace elements. At 30℃ pH 7.0, 10% inoculation amount, and 144 h cultivation time, the effective number of living bacterium of YA\|07 can reach 1.58×109 cfu/g, and the spore rate can reach 91.3%. In this study, the effective number of viable cells and rate of Bacillus mucilaginosus spores were increased by solid fermentation, which not only improved the quality of microbial fertilizer, but also reduced the environmental pollution, so it is of important significance for promoting the development of green agriculture in China.

Key words: Bacillus mucilaginosus, solid fermentation, classification and identification, orthogonal experiment, single factor experiment