Impact of physico-chemical parameters on synthesis of Polyhydroxybutyrate (PHB) produced from Bacillus toyonensis KUMBNGBT-62

Gurubasajar, Nandish and Basaiah, Thippeswamy (2025) Impact of physico-chemical parameters on synthesis of Polyhydroxybutyrate (PHB) produced from Bacillus toyonensis KUMBNGBT-62. World Journal of Biology Pharmacy and Health Sciences, 21 (3). pp. 412-423. ISSN 2582-5542

The biosphere is seriously threatened by the various very hazardous chemicals employed in the manufacturing of synthetic plastic. A bio-derived and biodegradable polyester polymer, polyhydroxybutyrate (PHB) is created by a variety of species, including P3HB, P4HB, PV, PH, and PHO, as well as their copolymers. The PHB-producing bacterium was isolated from soil sample collected at garbage site in Jogfalls, Sagar Taluk, Shivamogga District, Karnataka, India. The bacteria was identified based on its physical characteristics and screened by using several staining techniques and species level identification was achieved using the 16S r-RNA gene sequencing method. A variety of circumstances were used to analyse the fabrication of PHB. Low-cost agro based products were used to produce PHB on a large scale, and UV-visible spectrophotometric analysis was used to calculate the amount of PHB contained in the removed bacterial cells. Bacillus toyonensis KUMBNGBT-62 was gram positive, motile and spore forming bacterium and confirmed by using 16S r-RNA sequence and deposited to GenBank, NCBI and assigned with accession No. OK136177. Additionally, nutritional broth medium, a 72-hour incubation period, 37˚C temperature, pH 7.0, glucose as a carbon source, ammonium chloride as a nitrogen source and a 4:1 carbon-nitrogen ratio supports highest accumulation of PHB. At ʎ-max of 290 nm and liquid hydrolysate of feed stock, the highest level of PHB formation was detected. Bacillus toyonensis is demonstrated to maximize PHB production using low-cost residues, reducing production costs and serving as a model organism for large-scale bio-based plastics production.