文献类型：期刊文献

英文题名：Plant Proteins as an Alternative Nitrogen Source for Chiral Purity L-Lactic Acid Fermentation from Lignocellulose Feedstock

作者：Zhang, Bin[1];Wu, Lei[1];Liu, Xiucai[2];Bao, Jie[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Cathay Biotech Inc, 1690 Cailun Rd,Zhangjiang Hitech Pk, Shanghai 201203, Peoples R China

年份：2022

卷号：8

期号：10

外文期刊名：FERMENTATION-BASEL

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000872437800001)】；

基金：This research was funded by the National Natural Science Foundation of China (31961133006, 21978083).

语种：英文

外文关键词：lactic acid; optical purity; lignocellulose; cheap nutrients; cottonseed meal

摘要：High optical purity lactic acid is in high demand as the precursor for synthesizing polylactic acid (PLA). The costs of expensive carbohydrates and nitrogen source materials accounts for a large portion of the production costs in lactic homo-fermentation. The use of lignocellulosic biomass for lactic acid production reduces the cost of the carbohydrate feedstock, but the cost of nitrogen sources is a big challenge when considering the high prices of general nitrogen sources. Low-cost nitrogen materials are vulnerable to being contaminated by exogenous mixed L-lactic acid and D-lactic acid; thus, their feasibility as nitrogen sources for the production of optically pure lactic acid products is hindered. The available reports focus on cost reduction using agro-industrial byproducts as nutrient sources, with these presenting fewer concerns on the effect of the optical purity of lactic acid-product monomers for polymerization. In this study, commonly used low-cost nutrient sources were characterized and screened for high optical purity L-lactic acid fermentation. Corn steep liquor (CSL), a widely used and cheap nutrient for lactic acid fermentation, was found not to be suitable because of its high content of mixed D-/L-lactic acids (up to 20%, w/w). On the other hand, cottonseed meal was found to be completely free of mixed L-/D-lactic acids. Therefore, the cottonseed meal was hydrolyzed with dilute sulfuric acid and used as a nitrogen source for L-lactic acid fermentation using lignocellulose feedstock as a substitution for yeast extract and peptone. The results showed that the final L-lactic acid titer reached 96.5 +/- 0.2 g/L from 25% (w/w)-solids loaded pretreated and biodetoxified wheat straw with a yield of 0.31 g/g feedstock and an optical purity of 99.7%. The techno-economic evaluation indicated that the cost of the cottonseed meal was only USD 0.193/kg of lactic acid product, and the minimum lactic acid selling price (MLSP) was USD 0.813/kg of lactic acid product, which was only 25.1% compared to the use of yeast extract and peptone as the nutrients. Cellulosic L-lactic acid production using cottonseed meal as a complex nutrient source showed competitive performance when compared to starch feedstock from food crops.