Statistical Design-Driven Optimization of Polyhydroxy-Butyrate (PHB) Production Using Sugarcane Bagasse by Brevibacterium sp. (PP989436) Strain

Cost-effective methods for producing Polyhydroxybutyrate (PHB) can make large-scale bioplastic manufacturing economically viable. This study aimed to optimize PHB synthesis using sugarcane bagasse, a renewable and inexpensive raw material, promoting sustainability by reducing waste and minimizing reliance on non-renewable resources. Soil organisms capable of PHB production were identified using Sudan Black B staining, and Brevibacterium sp. (PP989436) was selected for further study. The production process was optimized using Response Surface Methodology (RSM) and Central Composite Design (CCD) with the statistical analysis showing a significant effect of the optimized medium on PHB production (F-value: 5.17, p-value: <0.005) significantly enhancing PHB yield compared to an unoptimized medium. The optimized conditions resulted in a PHB yield of 7.4 g/L from 12.2 g/L dry biomass (60.65%). PHB characterization was performed using FTIR, NMR, and TGA, and a PHB film was synthesized for evaluation. No cytotoxic effects were observed in MTT and Brine Shrimp Lethality assays. This optimized, sustainable production process presents significant potential for industrial-scale applications, offering an environmentally friendly alternative to petroleum-based plastics.