Exploring the Potential of Two Bacterial Consortia to Degrade Cellulosic Biomass for Biotechnological Applications.

This paper outlines two cellulolytic bacterial consortia named SCS and SCB, isolated from soil samples of sugarcane (Saccharum officinarum) crop field, and a sugarcane bagasse deposit in an ethanol mill. Both consortia were able to grow on different carbon sources, such as sugarcane bagasse, corn husk, peanut hulls, and carboxymethylcellulose, releasing up to 11.90 µmol/mL and 15.23 µmol/mL of glucose for SCS and SCB, respectively. In addition, SCS and SCB have several strains capable of producing cellulase, amylase, lipase, and protease. Whole genome sequencing of the SCS consortium revealed that Burkholderia was the most prevalent genus, encompassing approximately 80% of the consortia. In addition, metagenome analysis allowed the identification of genes encoding enzymes related to starch and cellulose degradation, as well as enzymes related to lipases and proteases, confirming our initial findings. The results showed that SCS and SCB had the capability to degrade cellulose, and that they were an efficient source of enzyme production, which would provide a new choice for use in different biotechnological applications.

Properties of Polyhydroxyalkanoate Granules and Bioemulsifiers from Pseudomonas sp. and Burkholderia sp. Isolates Growing on Glucose.

A Burkholderia and Pseudomonas species designated as AB4 and AS1, respectively, were isolated from soil containing decomposing straw or sugar cane bagasse collected from Brazil. This study sought to evaluate the capacities of culture media, cell-free medium, and crude lysate preparations (containing PHB inclusion bodies) from bacterial cell cultures to stabilize emulsions with several hydrophobic compounds. Four conditions showed good production of bioemulsifiers (E24 ≥ 50 %), headed by substantially cell-free media from bacterial cell cultures in which bacterial isolates from Burkholderia sp. strain AB4 and Pseudomonas sp. strain AS1 were grown. Our results revealed that the both isolates (AB4 and AS1 strains) exhibited high emulsification indices (indicating usefulness in bioremediation) and good stabilities.

Chemical and rheological properties of exopolysaccharides produced by four isolates of rhizobia.

The rheological, physicochemical properties, emulsification and stability of exopolysaccharides (EPSs) from four rhizobia isolates (LBMP-C01, LBMP-C02, LBMP-C03 and LBMP-C04) were studied. The EPS yields of isolates under these experimental conditions were in the range of 1.5-6.63gL(-1). The LBMP-C04 isolate, which presented the highest EPS production (6.63gL(-1)), was isolated from Arachis pintoi and was identified as a Rhizobium sp. strain that could be explored as a possible potential source for the production of extracellular heteropolysaccharides. All polymers showed a pseudoplastic non-Newtonian fluid behavior or shear thinning property in aqueous solutions. Among the four EPS tested against hydrocarbons, EPS LBMP-C01 was found to be more effective against hexane, olive and soybean oils (89.94%, 82.75% and 81.15%, respectively). Importantly, we found that changes in pH (2-11) and salinity (0-30%) influenced the emulsification of diesel oil by the EPSs. EPSLBMP-C04 presented optimal emulsification capacity at pH 10 (E24=53%) and 30% salinity (E24=27%). These findings contribute to the understanding of the influence of the chemical composition, physical properties and biotechnology applications of rhizobial EPS solutions their bioemulsifying properties.