Polyhydroxybutyrate (PHB) bioplastic characterization from the isolate Pseudomonas stutzeri PSB1 synthesized using potato peel feedstock to combat solid waste management

Abstract

The global fossil-based plastic industry is at a crucial point, requiring bio-based polymers. Polyhydroxybutyrate (PHB) is formed under nutritional stress conditions; however, efficient bacteria and cheap substrates are needed. This study found that potato peel, a cheap and abundant carbon source, can improve PHB production. PHB crotonic assay screened 11 Sudan Black B and Nile red positive isolates for PHB production. PSB1, a Pseudomonas stutzeri PSB1 (MN539619) yields 2.39 g/L maximal PHB. PHB generation from high-carbon agro-wastes using Pseudomonas stutzeri PSB1was 3.09 g/L for potato peel. Plackett-Burman and CCD, a statistical optimization method, increased PHB production. After optimizing all CCD variables, potato peel, Urea, and RPM were found to increase PHB production (6.1 g/L). The optimized parameters extracted 3.98 g/L of PHB from 6.36 g/L of dry biomass of Pseudomonas stutzeri PSB1. FT-IR, NMR, TGA, and DSC were used to characterize and compare the extracted PHB biopolymer to Sigma Aldrich PHB powder. Extracted PHB-bioplastic was tested for tensile strength and Elongation at break. Based on the above criteria, the recovered PHB biopolymer from Pseudomonas stutzeri PSB1 is a good alternative to agricultural mulch films and non-biodegradable plastics.