Journal of Bioprocessing & Biotechniques

Study on the Effect of pH, Temperature and Aeration on the Cellular Growth and Xanthan Production by Xanthomonas campestris Using Waste Residual Molasses

Abstract

P. Mudoi, P. Bharali, BK. Konwar

Waste residual molasses, a non-edible portion produced during the processing of sugarcane juice for the preparation of molasses, may be an alternative low-cost renewable substrate to the pricey food-grade molasses for xanthan production. Systematic strategies were applied to improve xanthan production with a newly isolated indigenous strain Xanthomonas campestris originated from Tezpur, Assam. Analyses with TLC, HPLC and FTIR show that the polymer consisted mainly of glucose, galactose and glucornic acid but showed no evidence of xylose, arabinose or glycoprotein in the polysaccharide. The isolated xanthan exhibited all the required physico-chemical characteristics and were examined by using TGA, DSC, XRD and SEM. Maximum concentration of xanthan was observed after 24h of incubation of the culture media, pH 7 at 28°C with 200 rpm. The viscosity of xanthan was found to be stable over a wide range of pH, reduced with the increase in temperature and raised at the higher xanthan concentration. The results obtained in the present investigation are noteworthy for the possible xanthan production from low-cost waste residual molasses at an industrial level.