Exopolysaccharide Produced by Probiotic Bacillus albus DM-15 Isolated From Ayurvedic Fermented Dasamoolarishta: Characterization, Antioxidant, and Anticancer Activities

An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus albus DM-15, isolated from the Indian Ayurvedic traditional medicine Dasamoolarishta. Gas chromatography-mass spectrophotometry and nuclear magnetic resonance (NMR) analyses revealed the heteropolymeric nature of the purified EPS with monosaccharide units of glucose, galactose, xylose, and rhamnose. Size-exclusion chromatography had shown the molecular weight of the purified EPS as around 240 kDa. X-ray powder diffraction analysis confirmed the non-crystalline amorphous nature of the EPS. Furthermore, the purified EPS showed the maximum flocculation activity (72.80%) with kaolin clay and emulsification activity (67.04%) with xylene. In addition, the EPS exhibits significant antioxidant activities on DPPH (58.17 +/- 0.054%), ABTS (70.47 +/- 0.854%) and nitric oxide (58.92 +/- 0.744%) radicals in a concentration-dependent way. Moreover, the EPS showed promising cytotoxic activity (20 +/- 0.97 mu g mL(-1)) against the lung carcinoma cells (A549), and subsequent cellular staining revealed apoptotic necrotic characters in damaged A549 cells. The EPS purified from the probiotic strain B. albus DM-15 can be further studied and exploited as a potential carbohydrate polymer in food, cosmetic, pharmaceutical, and biomedical applications.

Automated summary

This study purified an exopolysaccharide (EPS) from a probiotic bacterium isolated from traditional Indian Ayurvedic medicine. The EPS exhibited heteropolymeric composition and showed various activities including flocculation, emulsification, antioxidant, and cytotoxicity. This research highlights the potential application of the purified EPS in various industries.