甜菜糖蜜乳酸发酵工艺参数的优化及酵母膏替代物的初探

Optimization of the Fermentation of Beet Molasses to Lactic Acid and the Research on the Substitution for the Yeast Extract

采用正交设计实验进行糖蜜发酵产乳酸的研究 .结果表明 ,在所选择的发酵温度、初始糖浓度、酵母膏用量和接种量 4个因素中 ,初始糖浓度对乳酸产量的影响最显著 .最佳发酵条件是 ,初始糖浓度 70g/L ,接种量 7% ,温度 37℃ ,酵母膏用量 3% .在此条件下 ,乳酸产量在发酵 72h时可达 4 0 g/L左右 .酵母膏作为一种辅料 ,对增加乳酸产量效果明显 ,但造价较高 .以厨房垃圾、豆渣、硫酸铵作为酵母膏的替代物 ,进行糖蜜发酵时 ,其糖底物都能被有效利用 ,乳酸转化率与酵母膏相当 ,但乳酸产量仍低于酵母膏 ,表明乳酸发酵是极为复杂的过程 ,不仅与氮源有关 。

Beet molasses is a kind of by-product of the sugar plant with plenty of sugar. It could be used in many fields of the industry. In order to acquire the maximum lactic acid concentration, an orthogonal experiment design was adopted. Four factors with three levels were considered in the experiment, which were initial sugar concentration, inoculum size, temperature and the quantity of yeast extract. The lactic acid concentration was significantly affected by the initial sugar concentration. The optimal fermen...