Quantification of exopolysaccharide produced by bacillus subtilis and the effect of different factors on its production

الملخص EN

The present study included the extraction and characterization of EPS production by a local soil isolate Bacillus subtilis and examine the effect of different factors pH, inoculums size, incubation periods, and carbon, nitrogen and phosphate sources on EPS production.

The exopolysaccharide was recovered from the culture supernatant by using a cold ethanol precipitation.

The total carbohydrate content was determined by phenol sulfuric acid method at 488 nm, and major structural groups were detected by Fourier transform infrared (FTIR) spectroscopy at frequency range of 400 to 4000 cm-1.

Basal salt solution (BSS) showed higher efficacy in supporting the bacteria to produce EPS (0.986 mg / ml) as dry weight.

The study showed that glucose and fructose were gave maximum EPS production as a carbon source along with ammonium chloride as a nitrogen source.

The optimal medium conditions were pH 7.0, inoculum size 5-6 %, after four days of incubation to promote the maximum EPS production for the bacteria under study.