A type of biodegradable polymer called polyhydroxybutyrate (PHB) is created naturally by some bacteria as a means of storing energy. PHB is seen as a possible substitute for plastics made from petroleum because of its biodegradability and renewable status. The current research study uses various agro-industrial residues to isolate, screen, characterize, optimize and quantify bacteria that produces PHB. The powerful bacterium that generates PHB was found in a scrap yard in Rangenahalli, Chikkamagaluru (Dist.), Karnataka, INDIA. The selected bacteria were non-spore-forming, non-motile and Gram-negative. Sudan b black staining indicated the granules’ existence in the bacteria. Achromobacter xylosoxidans was recognized and confirmed based on its phenotypic and genotypic characteristics. The 16s rRNA gene's partial sequence was submitted to NCBI, GenBank and given the Accession number OK103997. The growth conditions necessary for the most production of PHB are optimized using a variety of physical and chemical factors, including nutrient broth medium, a 72-hour incubation period, a 37°C temperature, a pH of 7.0, glucose as a source of carbon, ammonium chloride as a source of nitrogen and a carbon-nitrogen ratio of 4:1. The bacterium that produces PHB was grown on several agro-industrial waste products, with feedstock hydrolysate showing the highest level of PHB generation. The 298 nm ʎ-max is provided by the UV-visible spectrophotometric measurement, which also measures and validates the generation of PHB. All of these results indicate that the isolated Achromobacter xylosoxidans is a productive PHB producer that can be used to make PHB biopolymers.