Madhuca indica flower extract as cheaper carbon source for production of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) using Ralstonia eutropha

[Display omitted] •Poly (3-hydroxy butyrate-co-3 hydroxyvalerate) was produced using Madhuca indica flower.•The bacterial strain Ralstonia eutropha produced 1.44 g/l of PHBV at optimized condition.•The polymer showed excellent biodegradation and corrosion resistance. In this study, the poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was synthesized using Madhuca indica flower extract as cheaper carbon source by Ralstonia eutropha. The Influence of fermentation parameters such as incubation time, temperature, pH and inoculum size were studied on production of PHBV. The maximum production of PHBV (1.44 ± 0.016 g/l with yield of 49.4%) was obtained at a temperature, pH, inoculum size and incubation time of 35 °C, 6, 5% v/v and 48 h, respectively. The PHBV was characterized using nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric/differential scanning calorimetric (TGA/DSC) and scanning electron microscopic (SEM) analysis. The biodegradation and corrosion resistance of the polymer were also studied. The functional group CO was observed in the FTIR spectrum indicated the presence of PHA. Moreover, the NMR spectrum showed the formation of hydroxyvalerate copolymer. Hence, it can be confirmed that the synthesized polymer was PHBV. TGA analysis showed that the maximum decomposition occurred at a temperature of 474 °C. The DSC showed the dual melting point (136 °C and 140.69 °C), which inferred the re-crystallization behavior of synthesized PHBV. In addition, the PHBV showed good biodegradation and corrosion resistance. Henceforth, the Madhuca indica flower extract is suggested as cheaper carbon source for production of PHBV.