title: Effect of fermentation conditions on L-lactic acid production from soybean straw hydrolysate.
abstract: Four types of straw, namely, soybean, wheat, corn, and rice, were investigated for use in lactic acid production. These straws were mainly composed of cellulose, hemicellulose, and lignin. After pretreatment with ammonia, the cellulose content increased, whereas the hemicellulose and lignin contents decreased. Analytical results also showed that the liquid enzymatic hydrolysates were primarily composed of glucose, xylose, and cellobiose. Preliminary experiments showed that a higher lactic acid concentration could be obtained from the wheat and soybean straw. However, soybean straw was chosen as the substrate for lactic acid production owing to its high protein content. The maximum lactic acid yield (0.8 g/g) and lactic acid productivity (0.61 g/(l/h)) were obtained with an initial reducing sugar concentration of 35 g/l at 30°C when using Lactobacillus casei (10% inoculum) for a 42 h fermentation period. Thus, the experimental results demonstrated the feasibility of using a soybean straw enzymatic hydrolysate as a substrate for lactic acid production.
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, P.R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Qunhui
authors.initials: Q
authors.lastname: Wang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Xu
authors.forename: Wenyu
authors.initials: W
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Xiang
mesh_terms: D002475:Cellobiose / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D019344:Lactic Acid / Q000302:isolation & purification* / Q000378:metabolism*; D007780:Lacticaseibacillus casei / Q000378:metabolism*; D008031:Lignin / Q000737:chemistry / Q000378:metabolism; D012275:Oryza / Q000737:chemistry / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry / Q000378:metabolism; D014908:Triticum / Q000737:chemistry / Q000378:metabolism; D014961:X-Ray Diffraction; D014994:Xylose / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry / Q000378:metabolism
chemical_list: D002475:Cellobiose; D019344:Lactic Acid; D002482:Cellulose; D008031:Lignin; D014994:Xylose; D005947:Glucose