Butyric acid production from lignocellulosic biomass hydrolysates by engineered Clostridium tyrobutyricum overexpressing xylose catabolism genes for glucose and xylose co-utilization.
Clostridium tyrobutyricum can utilize glucose and xylose as carbon source for butyric acid production. However, xylose catabolism is inhibited by glucose, hampering butyric acid production from lignocellulosic biomass hydrolysates containing both glucose and xylose. In this study, an engineered strain of C. tyrobutyricum Ct-pTBA overexpressing heterologous xylose catabolism genes (xylT, xylA, and xylB) was investigated for co-utilizing glucose and xylose present in hydrolysates of plant biomass, including soybean hull, corn fiber, wheat straw, rice straw, and sugarcane bagasse. Compared to the wild-type strain, Ct-pTBA showed higher xylose utilization without significant glucose catabolite repression, achieving near 100% utilization of glucose and xylose present in lignocellulosic biomass hydrolysates in bioreactor at pH 6. About 42.6g/L butyrate at a productivity of 0.56g/L·h and yield of 0.36g/g was obtained in batch fermentation, demonstrating the potential of C. tyrobutyricum Ct-pTBA for butyric acid production from lignocellulosic biomass hydrolysates.
School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China; Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA.
Hongxin
H
Fu
Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA. Electronic address: yang.15@osu.edu.
Shang-Tian
ST
Yang
College of Animal Science, Zhejiang University, Hangzhou 310058, China.
Minqi
M
Wang
School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
Jufang
J
Wang
Bioprocessing Innovative Company, 4734 Bridle Path Ct., Dublin, OH 43017, USA.
I-Ching
IC
Tang
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D019149:Bioreactors; D020148:Butyric Acid / Q000378:metabolism*; D050260:Carbohydrate Metabolism / Q000235:genetics; D002482:Cellulose / Q000737:chemistry; D048014:Clostridium tyrobutyricum / Q000235:genetics / Q000378:metabolism*; D005285:Fermentation; D015870:Gene Expression; D005818:Genetic Engineering; D005947:Glucose / Q000378:metabolism*; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D031786:Saccharum / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
D001426:Bacterial Proteins; D020148:Butyric Acid; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; C027433:bagasse; D014994:Xylose; D005947:Glucose
Butyric acid; Clostridium tyrobutyricum; Glucose carbon catabolite repression; Lignocellulosic biomass hydrolysates; Xylose