Enhanced production of SCL-LCL-PHA co-polymer by sludge-isolated Pseudomonas aeruginosa MTCC 7925

Aim: To boost short-chain-length-long-chain-length polyhydroxyalkanoate (SCL-LCL-PHA) co-polymer yield in Pseudomonas aeruginosa MTCC 7925 by manipulating culture conditions. Methods and Results: Stationary phase culture of P. aeruginosa MTCC 7925 was subjected to various doses of different carbons and, N and P deficiencies. Enhanced co-polymer yield was recorded under ethanol- and glucose-supplemented cultures. Interaction of ethanol with N-deficiency boosted co-polymer accumulation maximally. Conclusions: The sludge-isolated P. aeruginosa MTCC 7925 demonstrated good capability to synthesize SCL-LCL-PHA co-polymer from unrelated carbon sources. Supplementation of ethanol under N-deficiency boosted the co-polymer yield up to 69% of dry cell weight, which is significantly higher when compared with other SCL-MCL-PHA co-polymer accumulating bacterial species. Significance and Importance of the Study: This is the first report on P. aeruginosa MTCC 7925, which is capable of accumulating LCL 3-hydroxyhexadecanoate and 3-hydroxyoctadecanoate units with SCL 3-hydroxybutyrate and 3-hydroxyvalerate as constituents of PHAs. This opens up new possibilities for various industrial applications owing to the superior properties of this new co-polymer.