Optimization and characterization of PHA from isolate Pannonibacter phragmitetus ERC8 using glycerol waste

Polyhydroxyalkanoates (PHAs) have been considered as a good alternative for petrochemical based polymers due to its biodegradability. However, a high production cost limits their acceptance in industries. In present work, efforts have been made to optimize the production of PHA by Pannonibacter phragmitetus ERC8 using glycerol waste as a sole carbon source, with enhanced polymer production in a cost effective way. To check the possibility of growth and polymer accumulation potential of P. phragmitetus ERC8, various low cost substrates such as food waste, mutton tallow, whey, sugarcane bagasse, corn steep liquor and glycerol waste were used. Optimum concentration of selected factors obtained as response of statistical experimental design were 0.8% (v/v) glycerol waste, 0.26% (w/v) BHM and 1.25%OD as an inoculum for the maximum PHA production. The suggested model was validated and maximum 1.36 g/L of PHA production was obtained after 96 h. PHA production of 1.87 g/L was achieved in 5 L (working volume 3 L) lab scale bioreactor with the suggested media components by RSM (Response Surface Methodology). Characterization of the PHA by NMR spectroscopy revealed that the polymer was a hetromonomer of (R)-3-hydroxybutyrate and medium chain length 3HA[(R)-3-hydroxyalkanoate] monomers.