PREPARATION AND CHARACTERIZATION OF POLY(BETA-HYDROXYALKANOATES) OBTAINED FROM PSEUDOMONAS-OLEOVORANS GROWN WITH MIXTURES OF 5-PHENYLVALERIC ACID AND NORMAL-ALKANOIC ACIDS

Pseudomonas oleovorans was grown with various mixtures of 5-phenylvaleric acid, PA, and either n-nonanoic acid, NA, or n-octanoic acid, OA. The resulting polymers contained the 3-hydroxyalkanoate units produced from either NA alone or OA alone and 3-hydroxy-5-phenylvalerate (HPV) units from PA. The mole fraction of HPV units in the polymeric products increased as the mole fraction of 5-phenylvaleric acid was increased in the feed, but close investigation of substrate consumption, cell growth, and polymer production revealed that P. oleovorans utilized 5-phenylvaleric acid and the n-alkanoic acid independently to produce mixtures of poly(beta-hydroxy-5-phenylvalerate) (PHPV) and the poly(beta-hydroxyalkanoate) (PHA), produced from either n-alkanoic acid alone. The molecular weights of the two types of PHAs produced were independent of the ratio of two organic acid substrates and of the growth time.