There has been a great concern from scientists to investigate marine microorganisms as a new source of pharmaceutical, antimicrobial and industrial compounds. 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 gm/L) from Klebsiella sp. isolated from marine environment of Qaroun Lake, Egypt. The high exopolysaccharide yield was achieved by optimization of different environmental conditions (shaking speed, pH, and incubation time), fermentation carbon source (glucose, fructose, sucrose, glycerol, and sodium ti-citrate), fermentation Nitrogen source (peptone, casein hydrolysate, tri- ammonium citrate, ammonium sulfate and urea) and inorganic salts (K2HPO4, MgSO4, and MnSO4). The selected Klebsiella sp. was first selected from all other marine bacterial isolates, according to its initial production of high culture viscosity and exopolysaccharides. Then the selected strain was identified by conventional methods and molecular characterization using 16S rRNA gene sequencing. This characterized marine strain of Klebsiella sp. can be cultured using the optimal conditions that were described here to gain the maximum production of exopolysaccharide which need to be tested for its beneficial activities.
Key words: Exopolysaccharide; 16S rRNA; Klebsiella sp; PCR, Sequencing; Marine Bacteria
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