The production of L-lactic acid was investigated in combination with the production of protein concentrates in the frame of a green biorefinery for efficient utilization of grasses and legume crops. Alfalfa green juice was the sole substrate utilized for initial lactic acid fermentation with Lactobacillus salivarius, Lactobacillus paracasei or Bacillus coagulans in order to drop the pH and precipitate the plant proteins present in the juice. Afterwards, proteins were separated by microfiltration with 40-42% of protein recovery into protein concentrates, suited for feeding monogastric animals. The (residual) brown juice was investigated as source of nutrients for producing L-lactic acid from glucose or xylose with B. coagulans A107 or B. coagulans A166, respectively. Fermentation of glucose (30, 60, 100 g L^-1) resulted in productivities of 2.8-4.0 g L^-1 h^-1 and yields of 0.85-0.91 g LA per g consumed glucose. Fermentation of xylose (30, 60 g L^-1) resulted productivities of 1.1-2.3 g L^-1 h^-1 and yields of 0.83-0.88 g LA per g consumed xylose. Comparing different brown juices, initial green juice fermentation with B. coagulans is recommended if the brown juice is to be used for producing L-lactic acid. Based on our results, it is possible to combine protein recovery with lactic acid production, and the brown juice proved to be a good nutrient source for L-lactic acid production with high optical purities.

在绿色生物精炼厂的框架内，结合蛋白质浓缩物的生产对 L-乳酸的生产进行了研究，以有效利用草类和豆类作物。苜蓿青汁是用于与唾液乳杆菌、副干酪乳杆菌或凝结芽孢杆菌进行初始乳酸发酵的唯一底物，以降低 pH 值并沉淀汁液中存在的植物蛋白。之后，通过微滤分离蛋白质，将 40-42% 的蛋白质回收成蛋白质浓缩物，适合喂养单胃动物。研究了（残留的）棕色汁液作为从葡萄糖或木糖与凝结芽孢杆菌生产 L-乳酸的营养来源分别为A107 或B. coagulans A166。葡萄糖（30、60、100 g L ^-1）的发酵产生2.8-4.0 g L ^-1  h ^{-1 的}生产率和每克消耗的葡萄糖0.85-0.91 g LA的产量。木糖(30, 60 g L ^-1 )的发酵产生1.1-2.3 g L ^-1  h ^{-1 的}生产率和每克消耗的木糖0.83-0.88 g LA的产量。比较不同的棕色果汁，用凝结芽孢杆菌进行初始绿色果汁发酵如果将棕色汁液用于生产 L-乳酸，则推荐使用。根据我们的研究结果，可以将蛋白质回收与乳酸生产相结合，并且棕汁被证明是生产具有高光学纯度的 L-乳酸的良好营养来源。