Production and Characterization of Exopolysaccharide from Novel Bacillus sp. M3 and Evaluation on Development Sub-Chronic Aluminum Toxicity Induced Alzheimer’s Disease in Male Rats

The number of patients suffering from Alzheimer’s Disease (AD) all over the world is rising continually and becomes one of the biggest challenges for most societies throughout the world. The potential of peripheral biochemical markers as complementary tools in the neuron-phsychiatric evaluation of these patients has claimed further attention. The aims of our study were to isolate the bacteria that able to produce exo-polysaccharides and to characterize then exopolysaccharide producing strains by 16S rDNA sequencing method. The exopolysaccharide (MEPS) produced from a newly isolated Bacillus sp. M3 was obtained by ethanol precipitation (6.5 g L^-1 growth medium). The molecular masse of the MEPS was 1.45×10⁴ g/mol wherein FT-IR, UV-Vis spectral analyses revealed prevalence of characteristic primary belonged to α-type exopolysaccharide with a pyran ring. Further, HPLC analysis revealed its two monosaccharide constituents galacturonic acid and glucuronic acid at molar ratio of 1:1. The second stage was the evaluation of anti-intoxicated effect of MEPS against aluminum chloride induced Alzheimer in rat relevant to its effect on oxidative stress, antioxidant brain status, cholinergic markers and serum level of S100B protein together with polysaccharide sub-chronic toxicity at 1/10 LD₅₀ in both AD and control experimental animal groups to find their diagnostic value in this disease. MEPS ameliorated antioxidant status and reduced all oxidative stress parameters in brain tissue with decreasing S100B as compared to aluminum toxicant group with significant acetyl cholinesterase inhibition which increase acetylcholine concentration in brain tissue. No toxicity was observed for MEPS in sub-chronic toxicity study for 90 days in all rat organs or liver and kidney function.