纳豆菌发酵对豆粕脲酶活性的影响

Effect of Fermented Bacillus natto on Urease Activity of Soymeal

微生物发酵可一定程度降低豆粕抗营养因子活性,提高豆粕作为蛋白源的利用率。采用2株纳豆菌发酵研究豆粕中脲酶的失活情况。首先测定了其生长曲线,用以指导其发酵条件的优化研究。研究了水/豆粕比例、培养温度、pH、接种量等发酵参数对脲酶活性的影响,结果表明:降低脲酶活性的最优发酵条件为:水/豆粕比例为5∶1,pH4.5、温度30℃、接种量5%、种龄为8h,发酵60h,豆粕脲酶活性降低93%。

Microorganlsm fermentation could decrease the activity of soymeal antinutrition factors in certain extent, and increase the use efficiency of protein sources. This paper studied the inactivation of urease by fermentation of two strains of Bacillus natto. The growth curves of Bacillus natto were set out and instructed to optimize its fermentation conditions. Effect of fermentation parameters, such as the ratio of water and soymeal, culturing temperature, and inculating amount, on urease activity was investigated. The results indicated that the optimized fermentation conditions were soybean meal as basic material, the ratio of water and material 5：1, pH 4.5, the original temperature 30℃, the inculating amount 5%, the ages of inoculures 8 h and the cycle of fermentation 72 h. Under the optimized condition,93% urease activity of soymeal was inactivated.