Characterization and Enhanced Production of PHB from a Halophyte-Associated Bacillus cereus Strain

Considering the importance of plant-associated microbes, this study was designed to explore the industrially important hydrolytic enzymes and poly-(3-hydroxybutyrate) (PHB) synthesizing potential of a bacterial strain, Bacillus cereus S3, isolated from a halophyte, Aeluropus lagopoides (L.) Thwaites. Factors affecting PHB production were optimized using the Plackett-Burman design (PBD). Granules of PHB were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). B. cereus S3 produced 166.66 mg L^-1 PHB under optimized conditions when pH 7, temperature 30 °C, incubation time 48 h, 10% (v/v) inoculum size, and 1% (w/v) lactose were used. The granular structure of PHB was observed under SEM. Results of FTIR showed that OH, CH, C-O, CO, and CH₂ were present in PHB. This study revealed the ability of the bacterium associated with A. lagopoides to efficiently produce a PHB polymer that can be used to manufacture biodegradable plastics.