双低菜籽粕混菌固态发酵条件的优化

Fermentation of double-low rapeseed meal by mixed solid culturing

【目的】利用纳豆芽孢杆菌和短乳杆菌对双低菜籽粕进行混菌固态发酵,优化发酵条件,提高双低菜籽粕的饲用品质。【方法】利用纳豆芽孢杆菌和乳酸菌对双低菜籽粕进行固态发酵(先接入纳豆芽孢杆菌再接入短乳杆菌),以发酵产物中的纳豆激酶活力常用对数值与三氯乙酸可溶性氮含量构成的综合评分为评价指标,通过单因素试验考查接种量、温度及料(g)水(mL)比对发酵效果的影响。选择接种量、温度及料水比为影响因子,根据boxbenhnken的中心组合试验设计原理采用三因素三水平的响应面分析筛选双低菜籽粕的最优发酵工艺。【结果】单因素试验得出最优接种量为每100g 1.5mL,最优的发酵温度为37℃,最优的料(g)水(mL)比为1∶1。响应面分析法确定的双低菜籽粕最佳发酵条件为接种量每100g 1.5mL,发酵温度37℃,料(g)水(mL)比1∶1.05,在该条件下发酵96h后发酵产物的综合评分为4.57。【结论】经优化的混菌固态发酵工艺对发酵后菜籽粕品质的综合提升具有良好效果。

[Objective] Bacillus natto and Lactobacillus brevis were used to improve feed quality of double-low rapeseed meal by optimizing fermentation conditions through multi-strains solid fermentation. [Method] The solid fermentation of double-low rapeseed meal using Bacillus natto and Lactobacillus brevis was conducted （Bacillus first and then Lactobacillus brevis）. Using the comprehensive evaluation index of logarithm of nattokinase and content of trichloroacetic acid soluble nitrogen （TCA-NSI）, single-factor tests were conducted to evaluate the effects of inoculums volume,temperature and ratio of solid tO liquid. Using inoculums volume,temperature and ratio of solid to liquid as influencing factors, the optimal fermentation process was determined by response surface methodology with 3 factors and 3 levels according to box-be- hnken experiment design principle. [Result] Through the single-factor test,the optimal inoculums volume, temperature,an ratio of solid to liquid（g ： mL） were 1.5 mL per 100 g,37 ℃ and 1 ： 1,respectively. Re- sponse surface methodology determined the optimal fermentation parameters were. inoculums volume 11 5 mL per 100 g,temperature 37℃ ,and ratio of solid to liquid （g ： mL） 1 ~ 1.05. The comprehensive grade was 4.57 after 96 h fermentation. [Conclusion] Optimal multi-strains solid-fermentation process was effec- tive to improve the quality of fermented rapeseed meal.