Jinfeng Sun1,2, Jie Wang3, Kangming Tian3, Zixing Dong3, Xiaoguang Liu3, Kugenthiren Permaul4, Suren Singh4, Bernard A Prior5, Zhengxiang Wang6. 1. School of Biotechnology, Center for Bioresource and Bioenergy, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. 2. School of Life Science and Food Engineering, Huaiyin Institute of Technology, 1st East Meicheng Road, Huaian, 223003, China. 3. Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China. 4. Department of Biotechnology and Food Technology, Durban University of Technology, Durban, 4002, South Africa. 5. Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa. 6. Department of Biological Chemical Engineering, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, TEDA, Tianjin, 300457, China. zxwang0519@tust.edu.cn.
Abstract
OBJECTIVES: To develop a xylose-nonutilizing Escherichia coli strain for ethanol production and xylose recovery. RESULTS: Xylose-nonutilizing E. coli CICIM B0013-2012 was successfully constructed from E. coli B0013-1030 (pta-ack, ldhA, pflB, xylH) by deletion of frdA, xylA and xylE. It exhibited robust growth on plates containing glucose, arabinose or galactose, but failed to grow on xylose. The ethanol synthesis pathway was then introduced into B0013-2012 to create an ethanologenic strain B0013-2012PA. In shaking flask fermentation, B0013-2012PA fermented glucose to ethanol with the yield of 48.4 g/100 g sugar while xylose remained in the broth. In a 7-l bioreactor, B0013-2012PA fermented glucose, galactose and arabinose in the simulated corncob hydrolysate to 53.4 g/l ethanol with the yield of 48.9 g/100 g sugars and left 69.6 g/l xylose in the broth, representing 98.6% of the total xylose in the simulated corncob hydrolysate. CONCLUSIONS: By using newly constructed strain B0013-2012PA, we successfully developed an efficient bioprocess for ethanol production and xylose recovery from the simulated corncob hydrolysate.
OBJECTIVES: To develop a xylose-nonutilizing Escherichia coli strain for ethanol production and xylose recovery. RESULTS:Xylose-nonutilizing E. coli CICIM B0013-2012 was successfully constructed from E. coli B0013-1030 (pta-ack, ldhA, pflB, xylH) by deletion of frdA, xylA and xylE. It exhibited robust growth on plates containing glucose, arabinose or galactose, but failed to grow on xylose. The ethanol synthesis pathway was then introduced into B0013-2012 to create an ethanologenic strain B0013-2012PA. In shaking flask fermentation, B0013-2012PA fermented glucose to ethanol with the yield of 48.4 g/100 g sugar while xylose remained in the broth. In a 7-l bioreactor, B0013-2012PA fermented glucose, galactose and arabinose in the simulated corncob hydrolysate to 53.4 g/l ethanol with the yield of 48.9 g/100 g sugars and left 69.6 g/l xylose in the broth, representing 98.6% of the total xylose in the simulated corncob hydrolysate. CONCLUSIONS: By using newly constructed strain B0013-2012PA, we successfully developed an efficient bioprocess for ethanol production and xylose recovery from the simulated corncob hydrolysate.
Authors: Edgar Olguin-Maciel; Alfonso Larqué-Saavedra; Patricia E Lappe-Oliveras; Luis F Barahona-Pérez; Liliana Alzate-Gaviria; Rubí Chablé-Villacis; Jorge Domínguez-Maldonado; Daniella Pacheco-Catalán; Hector A Ruíz; Raúl Tapia-Tussell Journal: Microorganisms Date: 2019-10-23