The polyhydroxyalkanoate (PHA) production and growth of Pseudomonas mosselii TO7, a newly isolated Pseudomonas
species from the wastewater of a vegetable oil manufacturing facility, was analyzed. Phenotypic analysis and phylogenetic
analysis of the 16S rRNA gene revealed that it is closely related to Pseudomonas mosselii. In the presence of palm
kernel and soybean oils, P. mosselii TO7 produced up to 50% cell dry weight (CDW) medium-chain-length (MCL) PHAs
comprising high poly(3-hydroxyoctanoate) (P(3HO)) content; P(3HO) content increased to 45% CDW when grown in
octanoate using a single-step culture process. The PHA monomer was identified by 13C nuclear magnetic resonance
spectroscopy. The average molecular weight and polydispersity index of PHA were 218.30 ± 31.73 and 2.21 ± 0.18,
respectively. The PHA produced by P. mosselii TO7 in the presence of palm kernel oil had two melting temperature (Tm)
values of 37.2C and 55.7C with melting enthalpy (DHm) values of 51.09 J gL1 and 26.57 J gL1
, respectively. Inhibition
analyses using acrylic and 2-bromooctanoic acids revealed b-oxidation as the primary pathway for MCL-PHA biosynthesis
using octanoic acid. Moreover, Pseudomonas putida GPp104 PHAL, harboring the PHA synthase genes of
P. mosselii (phaC1pm and phaC2pm) was used for heterologous expression, which demonstrated that phaC1pm is the
main PHA synthesis enzyme, and 3-hydroxyoctanoyl-CoA is its major substrate. This was the first report of a P. mosselii
TO7 isolate producing high-yield P(3HO) through utilization of plant oils