Water-soluble sulfated exopolysaccharide from Cytobacillus oceanisediminis: Its production, characterization and biological activities.

Abstract

Bacteria-derived exopolysaccharides (EPS) exhibit diverse bioactive properties, making them useful for biomedical, pharmaceutical, food, and cosmetic applications. In the present study, soil-derived bacterial isolates were screened for their EPS production capacity, and the isolate DT3-C was determined to be the highest EPS producer (0.4 g/L EPS). This isolate was identified as Cytobacillus oceanisediminis (GenBank No: OR826625). The EPS showed high solubility in water (90% above), moderate solubility in isopropanol, methanol and acetone, and poor solubility in DMSO and ethanol. Based on structural analyses, the EPS was determined to be a sulfated heteropolysaccharide consisting of rhamnose, xylose, arabinose, fructose, and glucose, with a molecular weight of 142 kDa. The EPS was found to possess significant anticancer activity against lung, colon, neuroblastoma, and prostate cancer cell lines. The qRT-PCR and ELISA findings suggested that the anti-cancer effect of EPS may be related to its potential to induce apoptosis. The EPS displayed moderate antioxidant capacity in radical scavenging assays (DPPH, hydroxyl, superoxide, and nitric oxide radicals). In addition, the EPS was able to protect dermal fibroblasts against H₂O₂-induced senescence, indicating its anti-skin aging potential. The EPS displayed anti-obesity potential an in vitro adipocyte model. It was determined that the biological activities of EPS are concentration-dependent. To the best of our knowledge, this is the first study focusing on the EPS production from C. oceanisediminis and the structural properties and biological activities of the purified EPS.