Genome assisted characterization and culture condition optimization for polyhydroxyalkanoate production by Streptomyces cavourensis BG2AG isolated from Chilika Lake

This study employed a whole genome based analysis to characterize Streptomyces cavourensis strain BG2AG isolated from Chilika Lake, India. The whole genome sequencing revealed a 7.56 Mb genome with 72.2% GC content, comprising 6737 coding sequences, 56 tRNA genes, and 2 rRNA genes. Functional annotation assigned 719 genes to metabolic pathways and 333 to secondary metabolite biosynthesis, while antiSMASH identified 32 biosynthetic gene clusters, indicating it’s intrinsic potential for intracellular polyhydroxy alkanoate (PHA) accumulation. Based on the information obtained from the genome analysis and the preliminary biochemical and physiological studies the strain was selected for culture condition optimization experiments using Taguchi experimental design. Under unoptimized culture conditions, BG2AG produced 0.30 ± 0.03 g/L PHA with ~42% cellular content whereas optimized conditions (glucose 1%, wheat bran 0.1%, pH 7, 37 °C, 96 h) significantly increased PHA yield to 0.724 ± 0.04 g/L. Taguchi analysis revealed that pH, temperature, and carbon source as major influencing factors. FTIR analysis confirmed characteristic ester functional groups of PHAs. These results demonstrate the feasibility of integrating genomic data with statistical optimization approaches to support polyhydroxyalkanoate production by Streptomyces cavourensis BG2AG.