Potential for mcl-PHA production from nonanoic and azelaic acids

James Gillis, Kenton Ko, Juliana A. Ramsay, Bruce A. Ramsay
2018 Canadian Journal of Microbiology (print)  
Greater than 65 % of canola and high oleic soy oil fatty acids is oleic acid, which is readily converted to nonanoic (NA) and azelaic (AzA) acids by ozonolysis. NA is an excellent substrate for medium-chain-length polyhydroxyalkanoate (mcl-PHA) production but AzA has few uses. Pseudomonas citronellolis DSM 50332 and Pseudomonas fluorescens ATCC 17400, both able to produce mcl-PHA from fatty acids and able to grow on AzA as the sole source of carbon and energy were assessed for the accumulation
more » ... f mcl-PHA from AzA and NA. In N-limited shake-flasks using NA, P. citronellolis produced 32% of its dry biomass as mcl-PHA containing 78% 3hydroxynonanoate with 22 % 3-hydroxyheptanoate. P. fluorescens produced only 2% PHA.. N-limited P. citronellolis on AzA produced 20% dry weight PHA containing 75% 3-hydroxydecanoate and 25% 3-hydroxyoctanoate, indicative of de novo synthesis. Although selective pressure, including β-oxidation inhibition, under well-controlled (chemostat) conditions was applied to P. citronellolis, no side-chain carboxyl groups were detected. It was concluded that one or more of FabG and PhaJ or the PHA synthase cannot catalyze reactions involving ω-carboxy substrates. However, a process based on oleic acid could be established if P. putida was engineered to grow on AzA.
doi:10.1139/cjm-2017-0554 pmid:29040817 fatcat:lv7p66l6tvfhvpv4fh2kp5nsce