纳豆芽孢杆菌／短乳杆菌混合发酵米糠的响应面工艺优化

Optimization of Rice Bran Fermented by Mixture of Bacillus Natto and Lactobacillus Brevis with Response Surface Methodology

以稳定米糠为主要基质，豆渣为营养因子，纳豆芽孢杆菌和保加利亚乳杆、嗜热链球菌、植物乳杆菌、瑞士乳杆菌、短乳杆菌为试验菌株，运用固态发酵技术，采用响应曲面法对益生菌混合发酵米糠的固体发酵工艺进行优化分析。试验结果表明：短乳杆菌最适于与纳豆芽孢杆菌混合发酵米糠，经响应面优化后最优发酵条件如下：米糠54％、豆渣6％、水40％、接种量10％、纳豆芽孢杆菌与短乳杆菌接种比例为1：1、温度34℃，先接入纳豆芽孢杆菌发酵3d后再接入短乳杆菌发酵2d。发酵后米糠中纳豆激酶产生量较其他混合菌种发酵方式明显提高，其中纳豆芽孢杆菌活菌数达到6．8×10^9cfu／g，短乳杆菌活菌数4．5×10^9cfu／g。

As a main material, stabilized rice bran has been fermented with solid -state fermentation by the single or mixture of Bacillus natto, Bulgaria lactobacillus, Streptococcus thermophiles, Lactobacillus plantarum, Lactobacillus helveticus and Lactobacillus brevis by respond surface methodology also with bean dregs added. The results indicated that the mixture of Lactobacillus brevis and Bacillus natto is the best for fermentation. The culture medium is made of 54% rice bran, 6% bean dregs and 40% water. The inoculation is ： 10% following the regular that Bacillus natto being inoculated first, after 3 d, inoculated with Lactobacillus brevis, the ratio between them as 1： 1, fermentation for 2 d at 34 ℃. Ultimately, the activity of nattokinase could improve significantly, and the viable count of Bacillus natto and Lactobacillus brevis are 6.8×10^9 and 4.5 ×10^9 cfu,/g respectively.