Synthesis and characterization of polyhydroxyalkanoates from soil bacterium Bacillus sp. PhNs9.

Background: Synthetic plastic pollution has increased tremendously over the past few decades. Supplanting synthetic plastics with a biodegradable alternative could save the biosphere from the drastic effects of plastic pollution. Polyhydroxyalkanoates (PHA) have been identified with the potential to become a feasible option. Results: A bacterial strain isolated from pavement soil was investigated for its PHA production ability. The isolated strain was found to be non‐virulent, and susceptible to various antibiotics, especially cefalexin, tetracycline, chloramphenicol, norfloxacin and ofloxacin. The carbohydrate utilization profile revealed that isolated bacteria can utilize different carbohydrates with a variable rate of consumption. The 16S rRNA identification revealed that the strain was related to the Bacillus genus. The produced PHA was predicted to be polyhydroxybutyrate as suggested by differential scanning calorimetry and NMR, Fourier transform infrared and Raman spectroscopies. Moreover, the hydrophobic nature of the PHA produced was confirmed by contact angle measurement. The growth, production and substrate utilization kinetics revealed the specific growth rate of Bacillus sp. PhNs9 was 0.07 h−1, specific biomass productivity was 0.06 g L−1 h−1 and specific PHA productivity was 0.05 g L−1 h−1. The yield of PHA from biomass was found to be 0.67 g per gram of biomass. Conclusions: The yield of PHA from the isolated strain was found to be higher than that of most earlier reports. Hence the findings of this study could catalyze the progress to completely move away from the use of synthetic plastics and replace them with an economical and sustainable solution. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]