Molecular cloning of polyhydroxyalkanoate synthesis operon from Aeromonas hydrophila and its expression in Escherichia coli.
The polyhydroxyalkanoate synthesis operon was cloned from Aeromonas hydrophila CGMCC 0911. Heterogeneous expression of the cloned polyhydroxyalkanoate synthesis operon in Escherichia coli resulted in accumulation of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) consisting of 13.9 mol % 3-hydroxyhexanoate up to 29.2 wt % of cell dry weight when grown in lauric acid. The cell dry weight of recombinant E. coli harboring the polyhydroxyalkanoate synthesis operon was improved to 1.7 g L (-1), which was much higher than that of 0.3 g L (-1) of the wild type E. coli. Coexpression of acyl-CoA dehydrogenase gene (yafH) from E. coli and Vitreoscilla hemoglobin gene (vgb) from Vitreoscilla together with the whole A. hydrophila CGMCC 0911 polyhydroxyalkanoate synthesis operon facilitated cell growth and polyhydroxyalkanoate accumulation in E. coli. When yafH was coexpressed together with the polyhydroxyalkanoate synthesis operon, the poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) content was increased from 29.2 to 52.1 wt %, and the cell dry weight was also increased slightly from 1.70 to 1.86 g L (-1). Coexpression of vgb gene could further enhance the cell dry weight to 2.0 g L(-1) and the polyhydroxyalkanoate content to 60.7 wt %.
Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, China.
Xiao-Yun
XY
Lu
Qiong
Q
Wu
Wan-Jiao
WJ
Zhang
Guang
G
Zhang
Guo-Qiang
GQ
Chen
D020155:3-Hydroxybutyric Acid / Q000378:metabolism*; D042964:Acyl-CoA Dehydrogenase / Q000235:genetics / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002208:Caproates / Q000378:metabolism*; D003001:Cloning, Molecular / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D005818:Genetic Engineering / Q000379:methods*; D006454:Hemoglobins / Q000235:genetics / Q000378:metabolism; D009876:Operon / Q000235:genetics; D054793:Truncated Hemoglobins; D000094122:Polyhydroxybutyrates
D020155:3-Hydroxybutyric Acid; D042964:Acyl-CoA Dehydrogenase; D001426:Bacterial Proteins; D002208:Caproates; D006454:Hemoglobins; D054793:Truncated Hemoglobins; C115940:poly(3-hydroxybutyrate-co-3-hydroxyhexanoate); D000094122:Polyhydroxybutyrates; C082613:hemoglobin protein, Vitreoscilla