RRC ID 35508
Author Xiong X, Wang X, Chen S.
Title Engineering of a xylose metabolic pathway in Rhodococcus strains.
Journal Appl. Environ. Microbiol.
Abstract The two metabolically versatile actinobacteria Rhodococcus opacus PD630 and R. jostii RHA1 can efficiently convert diverse organic substrates into neutral lipids mainly consisting of triacylglycerol (TAG), the precursor of energy-rich hydrocarbon. Neither, however, is able to utilize xylose, the important component present in lignocellulosic biomass, as the carbon source for growth and lipid accumulation. In order to broaden their substrate utilization range, the metabolic pathway of d-xylose utilization was introduced into these two strains. This was accomplished by heterogenous expression of two well-selected genes, xylA, encoding xylose isomerase, and xylB, encoding xylulokinase from Streptomyces lividans TK23, under the control of the tac promoter with an Escherichia coli-Rhodococcus shuttle vector. The recombinant R. jostii RHA1 bearing xylA could grow on xylose as the sole carbon source, and additional expression of xylB further improved the biomass yield. The recombinant could consume both glucose and xylose in the sugar mixture, although xylose metabolism was still affected by the presence of glucose. The xylose metabolic pathway was also introduced into the high-lipid-producing strain R. opacus PD630 by expression of xylA and xylB. Under nitrogen-limited conditions, the fatty acid composition was determined, and lipid produced from xylose by recombinants of R. jostii RHA1 and R. opacus PD630 carrying xylA and xylB represented up to 52.5% and 68.3% of the cell dry weight (CDW), respectively. This work demonstrates that it is feasible to produce lipid from the sugars, including xylose, derived from renewable feedstock by genetic modification of rhodococcus strains.
Volume 78(16)
Pages 5483-91
Published 2012-8
DOI 10.1128/AEM.08022-11
PII AEM.08022-11
PMID 22636009
PMC PMC3406118
MeSH Aldose-Ketose Isomerases / genetics Aldose-Ketose Isomerases / metabolism Carbon / metabolism Glucose / metabolism Lipid Metabolism Metabolic Engineering / methods* Metabolic Networks and Pathways / genetics* Phosphotransferases (Alcohol Group Acceptor) / genetics Phosphotransferases (Alcohol Group Acceptor) / metabolism Recombinant Proteins / genetics Recombinant Proteins / metabolism Rhodococcus / genetics Rhodococcus / growth & development* Rhodococcus / metabolism* Streptomyces lividans / enzymology Streptomyces lividans / genetics Xylose / metabolism*
IF 3.633
Times Cited 13
WOS Category BIOTECHNOLOGY & APPLIED MICROBIOLOGY MICROBIOLOGY
Resource
Prokaryotes E. coli ?