Physiological characterization and genetic engineering of Pseudomonas corrugata for medium-chain-length polyhydroxyalkanoates synthesis from Triacylglycerols

Pseudomonas belonging to the rRNA-DNA homology group I produce medium-chain-length (mcl)-polyhydroxyalkanoates (PHA). We show that P. corrugata, a member of this group, accumulates 0.5-1.0 g of mcl-PHA/L of culture when grown on glucose (Gl) or oleic acid (01). The predominant monomers of Gl-PHA and O1-PHA are P-hydroxydecanoate and P-hydroxyoctanoate, respectively. The molecular masses and polydispersity of P. corrugata PHAs are higher than those typically found with other Pseudomonas. We electrotransformed P. corrugata with a plasmid pCN51lip-1 carrying Pseudmonas lipase genes to generate strain III 111-1. The recombinant strain grew on intact triacylglycerols (TAGs) to 1.9-2.7 g of cell-dry-weight/L of culture. The yields and the predominant repeat-units of PHAs obtained from the lard- and tallow-grown III 111-1 were similar to those of O1-PHA from wild-type cells. In contrast to other Pseudomonas species, P. corrugata III 111-1 grown on TAGs at temperatures up to 36degreesC was not significantly affected with regard to cell yields, amounts of PHA produced, and the repeat unit compositions of the polymer.