Enhanced production and structural characterization of exopolysaccharide from Sporocarcina psychrophile MTCC 2908 through two step optimization for therapeutic evaluation

The production and extraction of Exopolysaccharide (EPS) from the bacterial strain Sporocarcina psychrophila (MTCC–2908) was carried out in submerged fermentation conditions, yielding 1.22 g/L in 48 h at unoptimized conditions. To enhance EPS yield, a two-stage optimization strategy was employed using Plackett-Burman design (PBD) for parameter screening, followed by central composite design (CCD) for optimization. To further enhance the yield of EPS. Ten fermentation parameters were initially screened via PB design, of which five (Glucose, NH₄Cl, K₂HPO₄, MgSO₄ 7H₂O, MgSO₄·H₂O) were identified as significant. These were further optimized using CCD. Under these conditions, maximum EPS production reached 21.62 g/L, representing a 17-fold increase compared to unoptimized conditions. Further, Lyophilized EPS was characterized using techniques Fourier Transform Infrared, Thermogravimetric Analysis, Atomic Force Microscopy, Scanning Electron Microscope, X-ray diffraction, total antioxidant capacity, and the reducing activity of the EPS. The purified EPS showed a moderate amount of antioxidant capacity and reducing activity, which may have a potent application in the pharmaceutical industry. The result of this study could serve as a promising candidate for further development of therapeutic applications of the EPS produced from Sporocarcina psychrophila MTCC–2908.