Synthesis of poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) by recombinant Escherichia coli

Abstract

Several recombinant Escherichia coli strains, including XL1‐Blue, JM109, HB101, and DH5α harboring a stable high‐copynumber plasmid pSYL105 containing the Alcaligenes eutrophus polyhydroxyalkanoate (PHA) biosynthesis genes were constructed. These recombinant strains were examined for their ability to synthesize and accumulate poly‐(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) [P(3HB‐co‐3HV)] copolymer from glucose and either propionate or valerate. All recombinant E. coli strains could synthesize the P(3HB‐co‐3HV) copolymer in the medium containing glucose and propionate. However, only the homopolymer poly‐(3‐hydroxybutyrate) [P(3HB)] was synthesized from glucose and valerate. The PHA concentration and the 3HV fraction could be increased by inducing with acetate and/or oleate. When supplemented with oleate, the 3HV fraction increased by fourfold compared with that obtained without induction. Induction with propionate resulted in lower PHA concentration due to the inhibitory effect, but an 3HV fraction of as high as 33.0% could be obtained. These results suggest that P(3HB‐co‐3HV) can be efficiently produced from propionate by recombinant E. coli by inducing with acetate, propionate, or oleate. © 1996 John Wiley & Sons, Inc.

Sequential Feeding of Glucose and Valerate in a Fed-Batch Culture of Ralstonia eutropha for Production of Poly(hydroxybutyrate-co-hydroxyvalerate) with High 3-Hydroxyvalerate Fraction

“…P(3HB-co-3HV) has been produced in the cultivations of Ralstonia eutropha (R. eutropha) (5,(9)(10)(11), recombinant Escherichia coli (E. coli) (12,13), Paracoccus denitrificans and Methylobacterium extorquens (14), Azotobater vinelandii (A. vinelandii) UWD (15), A. latus (16), and Alcaligenes Sp. SH-69 (17) with several different carbon sources such as glucose and propionate, glucose and valerate, methanol and n-amyl alcohol, sucrose and valerate, butyrate and valerate, or only glucose, propanol, and valerate, etc.…”

Biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) containing a predominant amount of 3-hydroxyvalerate by engineered Escherichia coli expressing propionate-CoA transferase

“…Although E. coli strains have been screened previously for P(HB-co-HV) production (Yim et al 1996), our purpose was to construct new strains that had the capacity to produce high intracellular concentrations of P(HB-co-HV) with different tolerances to propionate, and different expression levels of pct depending on IPTG responses. To impart PHA production in E. coli strains, we used pLW487 containing the acetoacetyl-CoA reductase (phaB), PHA synthase (phaC) and a b-ketothiolase gene (bktB) from Ralstonia eutropha, the product of which shows broader substrate specificity than other b-ketothiolases (phaA) implicated in PHB production (Slater et al 1998).…”

“…Pure propionate is expensive to produce industrially and is considerably more costly than glucose (Poirier et al 1995;Aldor et al 2002). In order to obtain adjustable 3HV contents for P(HB-co-HV) production, many efforts were taken, including varying the concentration of propionate in the fermentation process and altering the induction level of a critical gene such as propionyl-CoA synthetase (prpE), which makes propionyl-CoA from propionate (Fidler and Dennis 1992;Slater et al 1992;Yim et al 1996;Choi and Lee 1999;Aldor and Keasling 2001;Liu et al 2009). However, the 3HV content in PHA is not easily controllable, and it is typically quite difficult to produce polymer with >40 wt% 3HV monomer content by general fermentative methods (Aldor and Keasling 2001).…”

Involvement of the AtoSCDAEB regulon in the high molecular weight poly-(R)-3-hydroxybutyrate biosynthesis in phaCAB+ Escherichia coli

“…The recombinant pha þ E. coli fadR atoC(Con) strains are also abundantly used for the biosynthesis of the biodegradable storage PHA (Slater et al, 1992;Rhie and Dennis, 1995;Yim et al, 1996;Dennis et al, 1998;Fukui et al, 1999;Liu and Steinbüchel, 2000;Park et al, 2001;Kichise et al, 2002;Matsumoto et al, 2009). …”