Medium-chain-length poly(beta-hydroxyalkanoate) synthesis from triacylglycerols by Pseudomonas saccharophila

Pseudomonas saccharophila NRRL B-628 is capable of utilizing agricultural l ipids for growth. The organism exhibited good growth with triacylglycerol s ubstrates that contained saturated fatty acyl moieties such as coconut oil (CO; C10-12 fatty acids) and tallow (T; C16-18 fatty acids). Electron micro graphs of the triacylglycerol-grown cells showed the presence of intracellu lar granules indicative of poly(beta-hydroxyalkanoate) (PHA) production. Ce lls grown in a 250-ml CO-containing medium produced ca. 0.2 g of medium-cha in-length (mcl)-PHA. Gas chromatographic analysis showed that beta-hydroxyo ctanoic acid (30%), beta-hydroxydecanoic acid (40%), and beta-hydroxydodeca noic acid (16%) were the major monomer repeat-units of the GO-derived polym er. The estimated mean molecular mass of the GO-derived mcl-PHA as determin ed by gel permeation chromatography was 13.1 X 10(4) g/mol with a polydispe rsity of 3.16.