An innovative extracellular polysaccharide produced by Egyptian Marine Bacillus licheniformis, and its applications as antibacterial agent.

Abstract

Twenty-two marine bacterial isolates were collected from the Eastern Harbor (29885 E longitude and 31205 N latitude) located at Alexandria, Egypt selected to produce exopolysaccharides, using the Shene extraction method in 2008. The most potent marine bacterium was identified as Bacillus licheniformis SMRH1, accession number ON777836 by using 16s rRNA as a molecular identification technique. According to the chemical analysis, the obtained polysaccharide content is estimated by using Fourier Transform Infrared spectra FTIR spectrum of the extracted exopolysaccharide from Bacillus licheniformis which showed that it contains νOH at 3420cm-1, νC-H aliphatic at 2952cm-1, νC=O in range 1660-1630cm-1 and Nuclear magnetic resonance spectra NMR showed signals δ’S ppm at 1.22 (s, -CH3), 2.07 (s, -CH2 chain) and 2.35(m, -CH2) and Scanning electron microscope SEM which confirmed the amorphus shaped uneven texture polysaccharide at higher magnification of ×5000. The exopolysaccharide that was generated has antibacterial activity by forming a free hollow zone around it against some gram positive and gram-negative bacteria according to disc diffusion method. The innovatively produced exopolysaccharide also has anticoagulant activity. A recent study proved that the generated exopolysaccharide induced β-hemolysis. The high yield of exopolysaccharide was “0.7 g/l” by using different culture media such as nutrient broth, peptone water, and king ̓s B broth.