title: Improving lactic acid productivity from wheat straw hydrolysates by membrane integrated repeated batch fermentation under non-sterilized conditions.
abstract: Bacillus coagulans IPE22 was used to produce lactic acid (LA) from mixed sugar and wheat straw hydrolysates, respectively. All fermentations were conducted under non-sterilized conditions and sodium hydroxide was used as neutralizing agent to avoid the production of insoluble CaSO4. In order to eliminate the sequential utilization of mixed sugar and feedback inhibition during batch fermentation, membrane integrated repeated batch fermentation (MIRB) was used to improve LA productivity. With MIRB, a high cell density was obtained and the simultaneous fermentation of glucose, xylose and arabinose was successfully realized. The separation of LA from broth by membrane in batch fermentation also decreased feedback inhibition. MIRB was carried out using wheat straw hydrolysates (29.72 g/L glucose, 24.69 g/L xylose and 5.14 g/L arabinose) as carbon source, LA productivity was increased significantly from 1.01 g/L/h (batch 1) to 2.35 g/L/h (batch 6) by the repeated batch fermentation.
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China; College of Life Sciences, Hebei University, Baoding 071002, China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Benkun
authors.initials: B
authors.lastname: Qi
authors.affiliation: Department of Chemical and Biochemical Engineering, Center for Bioprocess Engineering, Building 229, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Jianquan
authors.initials: J
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Su
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Rashid
authors.initials: R
authors.lastname: Khan
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: yhwan@home.ipe.ac.cn.
authors.forename: Yinhua
authors.initials: Y
authors.lastname: Wan
mesh_terms: D005285:Fermentation; D006868:Hydrolysis; D019344:Lactic Acid / Q000378:metabolism*; D014908:Triticum / Q000378:metabolism*
chemical_list: D019344:Lactic Acid
keywords: Cell recycle; Lactic acid; Membrane; Repeated batch; Wheat straw hydrolysates