副干酪乳杆菌ZG19发酵烟草废水产L-乳酸的响应面优化

摘要

烟草废水中含有大量的可溶性糖、含氮化合物和矿物质等营养成分.为资源化利用烟草废水,以本实验室分离并保藏的一株产L乳酸的副干酪乳杆菌(Lactobacillus paracaseD ZG 19为发酵菌株,以烟草废水为发酵底料,L乳酸产量为响应值,采用响应面法(RSM)优化发酵工艺.通过Plackett-Burman试验筛选出对L乳酸产量影响最显著的因素,进一步设计爬坡试验逼近最优区域,然后设计Box-Behnken响应面优化,分析并确定最佳发酵工艺.结果表明,在发酵温度39℃、发酵时间30 h、菌种接种量10％条件下,得到L乳酸实际产量为15.16g/L,与预测值(15.35 g/L)拟合度达到98.76％,L乳酸产量显著提高.因此,采用此方法得到的优化工艺合理而有效,具有实际应用价值.%Tobacco wastewater contains large amounts of soluble sugar,nitrogen compounds,minerals and other nutrients.For resource utilization of tobacco wastewater,using L-lactic acid-producing Lactobacillus paracasei ZG19 which isolated and preserved in laboratory as fermentation strain,with tobacco wastewater as fermentation substrate and L-lactic acid yield as response value,the fermentation process was optimized using response surface methodology (RSM).By Plackett-Burman (PB) design,the most significant factors affecting the yield of L-lactic acid were screened.Based on the results of PB design,the steepest ascent experiment was designed to approach the optimal region,and by BBD-RSM optimization,the optimal fermentation process was analyzed and determined.The results showed that with conditions of inoculum 10％,fermentation temperature 39 ℃ and time 30 h,the actual yield of L-lactic acid was 15.16 g/L and the fitting degree was 98.76％ with the predicted value of 15.35 g/L.The yield of L-lactic acid increased significantly after optimization.Therefore,the optimal fermentation process was reasonable and available,which had practical application value.