Production and characterization of homopolymer poly(3-hydroxyvalerate) (PHV) accumulated by wild type and recombinant Aeromonas hydrophila strain 4AK4.
Aeromonas hydrophila 4AK4 normally produces copolyesters (PHBHHx) consisting of 3-hydroxybutyrate (C4) and 3-hydroxyhexanoate (C6). Wild type and recombinant A. hydrophila 4AK4 (pSXW02) expressing vgb and fadD genes encoding Vitreoscilla haemoglobin and Escherichia coli acyl-CoA synthase respectively, were found able to produce homopolyester poly(3-hydroxyvalerate) (PHV) (C5) on undecanoic acid as a single carbon source. The recombinant grew to 5.59 g/L cell dry weight (CDW) containing 47.74 wt% PHV in shake flasks when growth was conducted in LB medium and PHV production in undecanoic acid. The cells grew to 47.12 g/L CDW containing 60.08 wt% PHV in a 6 L fermentor study. Physical characterization of PHV produced by recombinant A. hydrophila 4AK4 (pSXW02) in fermentor showed a weight average molecular weight (M(w)) of 230,000 Da, a polydispersity of 3.52, a melting temperature of 103 degrees C and a glass transition temperature of -15.8 degrees C. The degradation temperature at 5% weight loss of the PHV was around 258 degrees C.
Shen
Xiao-Wen
XW
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
Yang
Yun
Y
Jian
Jia
J
Wu
Qiong
Q
Chen
Guo-Qiang
GQ
D016980:Aeromonas hydrophila / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D011091:Polyesters / Q000378:metabolism*; D011995:Recombination, Genetic; D014631:Valerates / Q000378:metabolism*
D011091:Polyesters; D014631:Valerates; C073314:poly(3-hydroxyvalerate)