title: Chemical and rheological properties of exopolysaccharides produced by four isolates of rhizobia.
abstract: 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.
authors.affiliation: Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil. Electronic address: cris8moretto@gmail.com.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Moretto
authors.affiliation: Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil. Electronic address: teluque@yahoo.com.br.
authors.forename: Tereza Cristina Luque
authors.initials: TC
authors.lastname: Castellane
authors.affiliation: Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil. Electronic address: erica_mendeslopes@yahoo.com.br.
authors.forename: Erica Mendes
authors.initials: EM
authors.lastname: Lopes
authors.affiliation: Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil. Electronic address: wpomori@hotmail.com.
authors.forename: Wellington Pine
authors.initials: WP
authors.lastname: Omori
authors.affiliation: Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil. Electronic address: lais_ps@hotmail.com.
authors.forename: Laís Postai
authors.initials: LP
authors.lastname: Sacco
authors.affiliation: Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil. Electronic address: egerle@fcav.unesp.br.
authors.forename: Eliana Gertrudes de Macedo
authors.initials: EG
authors.lastname: Lemos
mesh_terms: D004655:Emulsions / Q000737:chemistry; D006838:Hydrocarbons / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012212:Rheology; D012231:Rhizobium / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D054712:Salinity
chemical_list: D004655:Emulsions; D006838:Hydrocarbons; D011135:Polysaccharides, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Bioemulsifier; Biopolymers; Rhizobium