Goma xantana é um heteroexopolissacarídeo sintetizado por Xanthomonas utilizando glicose ou sacarose como fontes de carbono, além de outros micronutrientes. É de grande aplicação industrial, devido às suas propriedades reológicas. O caldo de cana é rico em nutrientes, podendo ser utilizado como substrato para obtenção de xantana, viabilizando a produção no País pela redução dos custos. O objetivo deste estudo foi testar a produção da xantana obtida com diferentes cepas nativas de Xanthomonas em meio de cultivo composto de caldo de cana (XCC) e compará-la com os valores obtidos com a sacarose (XS). Foram preparados meios com o mínimo dos requerimentos nutricionais, contendo sacarose ou caldo de cana, suplementados apenas com uréia (0,01%) e fosfato (0,1%), fermentados em shaker (28 °C, 250 rpm, 120 horas). A maior produção de xantana foi obtida com a Xanthomonas campestris manihotis e caldo de cana (33,54 g.L-1), valor aproximadamente dez vezes maior que o obtido com a sacarose (3,45 g.L-1). A viscosidade aparente a 25 s-1, 2,0% de goma e 25 °C foi de 99,36 mPa.s para XCC e de 500,43 mPa.s para XS. A biossíntese da xantana a partir do caldo de cana merece peculiar atenção, constituindo-se numa possibilidade promissora para sua produção em larga escala.

The xanthan gum is a heteroexopolysaccharide synthesized by Xanthomonas campestris in a culture medium using glucose or sucrose as carbon sources and other nutrients. Due to its rheological properties, it has been contributing for the range of applications in the food industry, pharmaceutical, and tertiary recovery of oil. Sugarcane is rich in nutrients (sugars and minerals) and can be used as a substratum for the xanthan production, which can be produced in Brazil due to its cost reduction. The objective of this study was to test the production of the xantana obtained with different culture native of Xanthomonas in medium composed of sugarcane broth (XSC) and to compare with the values obtained with sucrose (XS). Two medium cultures were used with the minimum of the nutrients, contained sucrose or sugar cane complemented with urea (0.01%) and K2HPO4 (0.1%), fermented in shaker (28 °C, 250 rpm, 120 hours). The best production was obtained using Xanthomonas campetris manihotis and sugarcane (33.54 g.L-1), approximately ten times bigger then obtained with the sucrose (3.45 g.L-1). The apparent viscosity for an aqueous solution of 2.0% of gum to 25 °C and 25 s-1 was 99.36 mPa.s for XSC and 500.43 mPa.s to XS. The biosynthesis of xanthan starting from sugarcane deserves peculiar attention, constituting like this, a promising possibility for gum production in wide climbs.

Xanthan is a polysaccharide synthesized by Xanthomonas bacteria and of extreme commercial importance as a microbial polysaccharide. The aim of this work was to produce xanthan using mozzarella cheese whey as substrate, by different isolates natives the Xanthomonas. The alternative medium for production was milk whey, urea and K2HPO4. The xanthan maximum productivity was 21.91 g L-1. Analysis of apparent viscosity was made in solutions of gum at 0.5-2.0%, 25-65 ºC with shear rate of 25-1000 s-1.The maximum viscosity found was 57.30 mPa.s. The isolates demonstrate capacity to degrade the lactose and to produce xanthan, being constituted an alternative for the industrial production.