POLY(3-HYDROXYALKANOATE)S PRODUCED BY PSEUDOMONAS-OLEOVORANS GROWN BYFEEDING NONANOIC AND 10-UNDECENOIC ACIDS IN SEQUENCE

Pseudomonas oleovorans was grown on nonanoic acid and 10-undecenoic ac id, which were fed in sequence. The poly(3-hydroxyalkanoate)s (PHAs) w hich were isolated from cells harvested at different growth times, wer e characterized by solvent fractionation, crosslinking ability, gel pe rmeation chromatography, H-1 NMR spectroscopy, and differential scanni ng calorimetry. Two glass transitions were observed for the PHAs produ ced, and these corresponded to those of the PHAs produced from nonanoi c acid [PHA(NA)] and 10-undecenoic acid [PHA(UA)] alone. The amounts o f PHAs with repeating units produced from nonanoic acid remained const ant while Pseudomonas oleovorans utilized UA for growth and PHA produc tion. The molecular weight distributions of the PHAs obtained at diffe rent growth times were also constant. A crosslinking study showed that these polymers were mainly physical mixtures of PHA(NA) and PHA(UA). However, a fractionation study indicated that small amounts of the PHA s contained repeating units from both substrates, PHA(NA,UA).