Bioconversion from crude glycerin by Xanthomonas campestris 2103: xanthan production and characterization

• Autor(a) principal: Brandão,L. V.
• Data de Publicação: 2013
• Outros Autores: Assis,D. J., López,J. A., Espiridião,M. C. A., Echevarria,E. M., Druzian,J. I.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Chemical Engineering
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322013000400006
• topic: Xanthan; Biodiesel waste; Xanthomonas isolate from Brazil; Drilling fluid

The production and rheological properties of xanthan gum from crude glycerin fermentation, a primary by-product of the biodiesel industry with environmental and health risks, were evaluated. Batch fermentations (28 °C/250 rpm /120 h) were carried out using crude glycerin, 0.01% urea and 0.1% KH2PO4, (% w/v), and compared to a sucrose control under the same operational conditions, using Xanthomonas campestris strain 2103 isolate from Brazil. Its maximal production by crude glycerin fermentation was 7.23±0.1 g·L-1 at 120 h, with an apparent viscosity of 642.57 mPa·s, (2 % w/v, 25 °C, 25 s-1), 70% and 30% higher than from sucrose fermentation, respectively. Its molecular weight varied from 28.2 to 36.2×10(6) Da. The Ostwald-de-Waele model parameters (K and n) indicated a pseudoplastic behavior at all concentrations (0.5 to 2.0 %, w/v) and temperatures (25-85 °C), while its consistency index indicated promising rheological properties for drilling fluid applications. Therefore, crude glycerin has potential as a cost-effective and alternative substrate for non-food grade xanthan production.