Molecular Characterization and Biological Activities of Biopolymers Produced from Marine Bacteria

Abstract

Numerous types of bacterial exopolysaccharides have been documented and some of them have been shown to have industrial and medical value. In the present study we achieved a high yield of exopolysaccharide production (8.92 g/l) from Klebsiella sp. isolated from marine environment of Qaroun Lake, Egypt. The selected strain was identified by conventional methods and molecular characterization using 16S rRNA gene sequencing. A comprehensive experiments was carried out, included modification of different culture were conditions such as pH, carbon sources, nitrogen sources, inorganic salts, incubation time and agitation. The selected marine Klebsiella sp. (NR_037084.1)was cultured using our optimal conditions to gain the maximum exopolysaccharide yeild. This product was characterized biochemically. Its total protein, total carbohydrate was determined and also the monosaccharide components were determined using paper chromatography. The produced exopolysaccharide and its modified derivatives were assessed for their biological activities. It showed anticoagulation activity, fibrinolytic activity and antibacterial activity against E.coli and Staphylococcus aureus.

Key words: Exopolysaccharide – Marine bacteria – Klebsiella– Production - Optimization