好氧堆肥用枯草芽孢杆菌GX2产芽孢工艺优化

Optimization of Sporulation Parameters for Aerobic Composting Bacillus subtilis GX2 Strains

芽孢杆菌是好氧堆肥微生物菌剂的重要组成部分,为降低菌剂生产成本、改善其品质及应用效果,对芽孢杆菌产芽孢工艺进行研究。首先,在摇瓶上进行枯草芽孢杆菌GX2的培养基及培养条件优化,在此基础上,在3 L发酵罐中进行分批补料优化研究,进一步提高细胞浓度,最后,通过单因素及正交试验研究,在3 L发酵罐中对产芽孢工艺进行了优化。结果表明,当pH为6.8、温度为50℃和搅拌转速为150 r/min时,发酵液中的活菌数达1.57×10^(10)CFU/mL,芽孢数达1.32×10^(10)CFU/mL,芽孢率为84.1%。堆肥用枯草芽孢杆菌GX2的发酵及产芽孢工艺优化可有效提高发酵液中的活菌数及芽孢率,降低菌剂的发酵及生产成本,为后续工业化生产及应用奠定基础。

Bacillus subtilis is an important microbial agent during the aerobic composting.To reduce the production cost and improve the quality and applicability of bacteria,the spore production process of Bacillus subtilis was studied.Firstly,the culture medium and environmental conditions of Bacillus subtilis GX2 were optimized using shaking flasks.Cell concentration was further increased by a batch feed optimization method in a 3 L fermenter.Finally,single-factor and orthogonal experiments were applied to optimize the spore-forming process.The results showed that the number of viable cells and spores in the fermentation broth reached 1.57×10^(10)CFU/mL and 1.32×10^(10)CFU/mL,respectively,and the spore rate was 84.1%when rotating under 150 r/min at pH 6.8 and 50℃.To conclude,the optimization of fermentation and spore production for Bacillus subtilis GX2 effectively increased the number of viable cells and spores in the fermentation broth,and reduced the cost of microbial agents.This work provides guidance for Bacillus subtilis culture and lays the foundation for subsequent industrial production and application of aerobic composting.