title: Utilization of by-products derived from bioethanol production process for cost-effective production of lactic acid.
abstract: The by-products of bioethanol production such as thin stillage (TS) and condensed distillers solubles (CDS) were used as a potential nitrogen source for economical production of lactic acid. The effect of those by-products and their concentrations on lactic acid fermentation were investigated using Lactobacillus paracasei CHB2121. Approximately, 6.7 g/L of yeast extract at a carbon source to nitrogen source ratio of 15 was required to produce 90 g/L of lactic acid in the medium containing 100 g/L of glucose. Batch fermentation of TS medium resulted in 90 g/L of lactic acid after 48 h, and the medium containing 10 % CDS resulted in 95 g/L of lactic acid after 44 h. Therefore, TS and CDS could be considered as potential alternative fermentation medium for the economical production of lactic acid. Furthermore, lactic acid fermentation was performed using only cassava and CDS for commercial production of lactic acid. The volumetric productivity of lactic acid [2.94 g/(L·h)] was 37 % higher than the productivity obtained from the medium with glucose and CDS.
authors.affiliation: Changhae Advanced Institute of Technology, Changhae Ethanol Co., Ltd., Palbok-Dong 829, Dukjin-Gu, Jeonju, 561-203, Republic of Korea.
authors.forename: Se-Kwon
authors.initials: SK
authors.lastname: Moon
authors.forename: Young-Jung
authors.initials: YJ
authors.lastname: Wee
authors.forename: Gi-Wook
authors.initials: GW
authors.lastname: Choi
mesh_terms: D056804:Biofuels; D003362:Cost-Benefit Analysis; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000096:biosynthesis*; D007778:Lactobacillus / Q000378:metabolism*; D002365:Manihot / Q000737:chemistry; D028321:Plant Preparations / Q000737:chemistry / Q000378:metabolism
chemical_list: D056804:Biofuels; D003470:Culture Media; D028321:Plant Preparations; D019344:Lactic Acid; D000431:Ethanol; D005947:Glucose