混合菌种固体发酵菜粕生产氨基酸肥料的条件研究

Study on Conditions in Solid-State Fermentation of Rapeseed Meal by Mixed Strains for Amino Acid Fertilizer

【目的】通过响应曲面法优化以菜粕作为主要基质,两株产蛋白酶菌株嗜麦芽糖寡养单胞菌Stenotrophomonas maltrophilia G12(FJ211222)和短小芽孢杆菌Bacillus pumilus K11(FJ211221)混合菌种固体发酵生产氨基酸肥料的发酵过程参数,为实际生产提供理论依据。【方法】利用响应曲面法(response surface methodology),中的Plackett-Burman设计和Box-Behnken设计完成整个优化过程,用Mintab15.0软件和Design-Expert7.0软件分析试验数据。【结果】最终确定了麸皮添加量,基质起始含水量和起始pH为影响固体发酵酶解过程的主要因素,得出固体发酵过程主要工艺参数:发酵周期6d,麸皮添加量14.1%,基质含水量54.4%,起始pH9.15,接种量5.0%,菌液体积比为1﹕1,每24h翻抛1次。【结论】发酵过程参数优化后的菜粕蛋白水解度达到了13.1%,增加了游离氨基酸和小肽含量。

【Objective】 An optimization of parameters in solid-state fermentation of rapeseed meal by mixture of two protease-producing bacterial strains Stenotrophomonas maltrophilia G12 （ FJ211222） and Bacillus pumilus K11 （FJ211221） for an amino acid fertilizer was studied to provide a theoretical basis in the industrial production. 【Method】 The fermentation processes were optimized by using of Response Surface Methodology （RSM） with Plackett-Burman Experiments and Box-Behnken Design. Data were analyzed with Design-Expert 7.0 software and Mintab 15.0 software. 【Result】 High amino acid production in fermentation processes was observed under the optimized condtions：6 days of fermenting,54.5% of initial moisture,initial pH value at 9.15,14.1% of wheat bran supplementation,5% of mixed inocula in equal volume,and one time of ventilation in 24 hours. 【Conclusion】 Under the optimized fermentation conditions,the degree of hydrolysis of rapeseed meal protein reached 13.1% with high contents of free amino acids and small peptides.