秸秆腐解菌剂发酵工艺的优化研究

Optimization of Fermentation Process for Straw Decomposing Inoculant

摘要:

为了优化腐解菌剂（枯草芽孢杆菌和酿酒酵母菌）发酵工艺，提高菌剂活性，采用单因素和正交试验方法研究了发酵培养基组成、培养条件及发酵罐小试生产的优化方案。结果表明，腐解菌剂最佳发酵培养基：葡萄糖10 g/L、胰蛋白胨5 g/L、麦芽糖2 g/L、酵母浸粉5 g/L、NaCl 4.0 g/L、KH₂PO₄1.0 g/L、MgSO₄·7H₂O 0.3 g/L、FeCl₃0.01 g/L、CaCl₂0.1 g/L；最佳培养条件：初始pH值7.0，培养温度30℃，转速180 r/min，菌落数达7.57×10⁹CFU/mL；发酵罐小试生产培养条件：搅拌速度180 r/min、通风量0.8～1.0 vvm、接种量2%，菌落数为13.82×10⁹CFU/mL，符合农业微生物菌剂含量要求。

Abstract:

In order to optimize the fermentation process of straw decomposing inoculants（Bacillus subtilis and Saccharomyces cerevisiae） and improve the inoculant activity, single-factor and orthogonal experimental methods were used to explore the optimization schemes for fermentation medium composition, culture conditions, and small-scale production of fermentation tanks. The results showed that the optimal fermentation medium for the straw decomposing inoculant was composed of glucose（10 g/L）, tryptone（5 g/L）, maltose（2 g/L）, yeast extract powder（5 g/L）, NaCl（4.0 g/L）, KH₂ PO₄（1.0 g/L）, MgSO₄·7H₂O（0.3 g/L）, FeCl₃（0.01 g/L）, and CaCl₂（0.1 g/L）. The optimal culture conditions were: initial pH 7.0, culture temperature of 30 ℃, rotation speed of 180 r/min, under which the colony count reached 7.57×10⁹ CFU/mL. For the small-scale production in fermentation tanks, the optimal culture conditions were: stirring speed of 180 r/min, ventilation rate of 0.8-1.0 vvm, and inoculation amount of 2%, with the colony count reaching 13.82×10⁹ CFU/mL, which meets the content requirements of agricultural microbial inoculants. This study provides a theoretical basis for the industrial production of straw decomposing inoculants.