Xanthan Gum Production by Xanthomonas campestris pv. campestris IBSBF 1866 and 1867 from Lignocellulosic Agroindustrial Wastes.

This study aimed to evaluate the properties of xanthan gum produced by Xanthomonas campestris pv. campestris 1866 and 1867 from lignocellulosic agroindustrial wastes. XG was produced using an orbital shaker in a culture medium containing coconut shell (CS), cocoa husks (CH), or sucrose (S) minimally supplemented with urea and potassium. The XG production results varied between the CS, CH, and S means, and it was higher with the CH in strains 1866 (4.48 g L-1) and 1867 (3.89 g L-1). However, there was more apparent viscosity in the S gum (181.88 mPas) and the CS gum (112.06 mPas) for both 1866 and 1867, respectively. The ability of XGCS and XGCH to emulsify different vegetable oils was similar to the ability of XGS. All gums exhibited good thermal stability and marked groups in the elucidation of compounds and particles with rough surfaces.

Simultaneous Biosynthesis of Polyhydroxyalkanoates and Extracellular Polymeric Substance (EPS) from Crude Glycerol from Biodiesel Production by Different Bacterial Strains.

Simultaneous synthesis of polyhydroxyalkanoates (PHAs) and polyglutamic acid (PGA) was investigated in cultures of Cupriavidus necator IPT 026, C. necator IPT 027, C. necator IPT 029, and Bacillus megaterium INCQS 425 strains in a medium containing 2.0 % sucrose or crude glycerol from biodiesel (CGB), in an orbital shaker (35 °C, 180 rpm, 72 h). All the strains tested simultaneously produced PHA and PGA in a medium containing CGB. The C. necator IPT026 culture provided higher molecular mass PHA and PGA (1128.55 and 835.56 kDa, respectively). B. megaterium INCQS 425 promoted PGA production (1.90 g L-1) with higher crystalline melting temperature (84.04 °C) and higher initial decomposition temperature (247.10 °C). Furthermore, the latter culture promoted the production of medium- and long-chain PHA (0.78 g L-1) with high crystalline melting temperatures (∼170 °C) and high initial decomposition temperature (307.53 °C) and low degree of crystallinity (20.2 %). These characteristics render these PHAs more appropriate and suitable for processes that require high temperatures, such as extrusion, increasing the possibility of industrial applications, especially in the packaging sector.