响应面法优化贝莱斯芽孢杆菌发酵水豆豉的工艺条件

发酵产品的质量与微生物的产酶能力和发酵条件息息相关。为提高水豆豉的发酵品质,采用单因素法结合响应面法对一株高产豆豉纤溶酶的贝莱斯芽孢杆菌发酵水豆豉的条件进行优化,以获取最佳的发酵条件。首先利用单因素法缩小发酵时间、温度和接种量的范围,然后通过响应面法以水豆豉中的氨基酸态氮含量和豆豉纤溶酶活性为指标,确定最优发酵条件为:时间5d,温度35℃,接种量0.01%。最终发酵的水豆豉氨基酸态氮含量为8.95g/kg,豆豉纤溶酶活性为420.05IU/g,与市售相比,豆豉纤溶酶活性升高约400倍。该研究为贝莱斯芽孢杆菌发酵水豆豉提供了理论依据。

Optimization of Technological Conditions for Fermented Soya Beans by Bacillus velezensis Using Response Surface Methodology

The quality of fermented product is closely related to the enzyme production capacity and fermentation conditions of the microorganisms.In order to improve the fermentation quality of fermented soya beans,the single factor method combined with the response surface method is used to optimize the fermentation conditions of fermented soya beans by a strain of Bacillus velezensis with high production of fibrinolytic enzyme.After single factor experiment,the ranges of fermentation temperature,time and inoculation amount are reduced.And then,the optimum fermentation conditions are determined by response surface method with amino acid nitrogen and fibrinolytic enzyme activity of fermented soya beans as the indicators,that is the time of 5 d,the temperature of 35℃and the inoculation amount of 0.01%.Finally,the amino acid nitrogen content is 8.95 g/kg,the fibrinolytic activity is420.05 IU/g.Compared with the commercial products,the fibrinolytic activity of fermented soya beans is increased by about 400 times.This study has provided a theoretical basis for the fermentation of fermented soya beans by Bacillus velezensis.