Characterization and in-vitro Alzheimer's Properties of Exopolysaccharide from Bacillus maritimus MSM1

Four bacterial isolates were obtained from marine sediments collected from Sahl Hashish, Hurghada Red Sea, Egypt. The four isolates were screened for exopolysaccharides (EPSs) production and acetylcholinesterase inhibition. The most promising isolate S16 provided the highest EPS yield (7.51 g/L) and acetylcholinesterase inhibition. It was identified morphologically and genetically using 16S rRNA gene sequence analysis as Bacillus maritimus. Physico-chemical analysis of BMEPS using UV-Vis was estimated uronic acid and sulfate contents are 24.7% and 18.3%, respectively. HPLC analysis indicated that mannuronic acid, glucouronic acid, glucose, and mannose are presented in a molar ratio of 0.8:1.0:2.8:2.3, respectively. Furthermore, FT-IR revealed an abundance of β-configurations. The GPC estimated the average molecular weight (Mw) as 4.31104 g/mol. BMEPS successfully inhibited AChE (IC50; 691.77± 8.65μg/ ml), BChE (IC50; 288.27±10.50μg/ ml), and tyrosinase (IC50; 3.34±0.09, 14.00± 0.14, and 22.96 ± 1.23μg/ ml during incubation durations of 10, 20, and 40 minutes). It also demonstrated a selective anti-inflammatory action against COX-2 rather than COX-1. Furthermore, BMEPS showed powerful antioxidant capabilities such as free radical and oxygen reactive species (ROS) scavenging, metal chelation, reduction capacbility, and suppression of lipid peroxidation. These activities are due to their distinct chemical composition. The findings of this study indicate that BMEPS has shown promising anti-disease Alzheimer's (AD) activity in vitro, qualifying them for inclusion in advanced In-vivo studies for the discovery of alternative treatments.