Use of Date Syrup as Agricultural Waste for Xanthan Production by Xanthomonas campestris

Xanthomonas campestris was used for producing xanthan gum using date syrup, prepared from low quality dates, as a substrate. Fermentation was carried out with date syrup and sucrose syrup at 28 ˚C and pH 6.8 in a rotary benmarin shaker (240 rpm). The effect of fermentation period (24, 48, 72, 96 and 120 h) on xanthan gum production was studied. The results showed that EPS concentration increased with an increase in fermentation time with a maximum yield of 0.89 g/100 mL after 96 h which was much higher than that of the sucrose-containing medium (0.18 g/100 mL).  The effect of pH on the yield of the purified xanthan was also examined. The optimum pH for xanthan production was determined to be 5.5. The xanthan obtained through this study was compared to commercial xanthan, and showed a very similar chemical composition confirmed by thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FT IR). The results revealed that date syrup has a potential to be used as a suitable substrate for xanthan production.