SEQUENTIAL PRODUCTION OF 2 DIFFERENT POLYESTERS IN THE INCLUSION-BODIES OF PSEUDOMONAS-OLEOVORANS

When Pseudomonas oleovorans was grown on a mixture of 5-phenylvaleric acid, PVA, and nonanoic acid, NA, the reserve polyester produced inclu ded both a homopolymer and a copolymer. The homopolymer poly-3-hydroxy -5-phenylvalerate, PHPV, contained only 3-hydroxy-5-phenylvalerate uni ts, while the copolymer contained the same long chain 3-hydroxyalkanoa tes as those present in the copolymer poly-3-hydroxynonanoate, PHN, wh ich is produced from nonanoic acid alone. The intracellular location o f each of these polymers was determined by selective staining of the i nclusion body granules with ruthenium tetraoxide and examination by tr ansmission electron microscopy showed that both types of polyesters oc curred in the same granule. PHN was present in the center of the granu le, while PHPV accumulated around the PHN in the inclusion body. The p roteins associated with the inclusion bodies were separated using sodi um dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). In a ll cases, two different polymerase enzymes of molecular weight 59 and 55 KDa were present, indicating that the same polymerase enzyme system was responsible for the production of both PHN and PHPV. Attempts wer e made to produce a random copolymer containing both alkyl and phenyla lkyl repeat units by varying the growth conditions, but a mixture of P HN and PHPV was always produced instead.