Production and characterization of xanthan gum by different strains of Xanthomonas campestris isolated from various natural sources in submerged culture

Abstract

The xanthan gum is an exopolysaccharide (EPS) of microbial origin, produced by the bacteria of the X. campestris. The objective of this research was to evaluate production of xanthan gum by different strains of X. Campestris isolated from various natural sources in submerge culture. Four bacterial strains of X. campestris were isolated from American and Romaine lettuce (Lactuca sativa) and broccoli (Brassica oleacea var. italic). Kinetic parameters of growth were determined in discontinuous cultivation of the isolated strains and one of reference. The effect of the oxygen and calcium in the cultivation media was evaluated about the growth of the reference strain demonstrating their influence in the growth of the microorganism and in the production of the exopolysaccharide. Kinetic parameters of studied strains showed appropriate tendencies. Xanthan gum was obtained from LR1-UCIN strain with yield of 8.84 g/L, viscosity of 1814 cP, and content of remains of piruvato of 5,10 %. Keywords: Exopolysaccharide, Exopolysaccharide bacteria, Xanthomonas campestris, Xanthan gum