Structural characterization, functional and biological activities of an exopolysaccharide produced by probiotic Bacillus licheniformis AG-06 from Indian polyherbal fermented traditional medicine.

Research paper by Annadurai A Vinothkanna, Ganesan G Sathiyanarayanan, Perumalsamy P Balaji, Krishnamurthy K Mathivanan, Arivalagan A Pugazhendhi, Yongkun Y Ma, Soundarapandian S Sekar, Ramasamy R Thirumurugan

Indexed on: 24 Jan '21Published on: 23 Jan '21Published in: International Journal of Biological Macromolecules


An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus licheniformis AG-06 isolated from the polyherbal fermented traditional medicine (Ashwagandharishta) of Indian Ayurveda. High-performance liquid chromatography (HPLC) based compositional analysis exhibits the heteropolymeric nature of the EPS consisting of galactose, rhamnose, xylose, mannose, and glucose, as the monomeric units. Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic analyses confirm the presence of typical carbohydrate polymer functional groups and structural units, respectively. The purified EPS demonstrates the web-like fibrous and porous nature in scanning electron microscopic and atomic force microscopic studies. The purified EPS had shown 71.83% and 67.79% of flocculation and emulsification activities, respectively. Antioxidant activity was evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), nitric oxide, and superoxide free radicals and the scavenging actions were increased in a dose-dependent manner. Moreover, the purified EPS exhibits a significant cytotoxic activity against the human lung carcinoma cells (A549), which strongly suggests the anticancer potential of the EPS derived from B. licheniformis AG-06. Copyright © 2018. Published by Elsevier B.V.