Isolation and characterization of bacteria from solid waste for production and quantification of polyhydroxybutyrate

Background: Polyhydroxyalkanoates (PHA) represent a category of bacterial polyesters synthesized intracellularly under nutrient-stress conditions, particularly with limited essential nutrients and abundant carbon sources, serving as storage compounds. PHBs are currently of significant interest as sustainable bioplastic alternatives. The main objective of the study was to isolate PHB-producing bacteria from the solid waste dumping yard. Materials and Methods: Five bacterial isolates were screened for PHB granule production by Sudan black B staining method. Estimation and characterization of cellular PHB production was done using different analytical techniques including Fourier transform infrared spectroscopy (FTIR) for molecular analysis and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX). Results: One isolate, a promising PHB producer, was identified by 16s rRNA sequencing and was found to be as Acinetobacter baumannii. Quantitative analysis revealed that the isolate was showing capacity to accumulate 48.71% PHB. Characterization by FTIR and SEM-EDX confirmed PHB formation, with elemental composition of 61.65 ± 2.74% carbon and 38.35 ± 4.44% oxygen. Conclusion: This study helps to understand microbial PHB isolation and purification processes, and its supporting role in advancement of bioplastic production. Further research facilitates the development of sustainable bioplastic alternatives on a larger scale. Keywords: Polyhydroxyalkanoates, Polyhydroxybutyrate, Acinetobacter baumannii.