title: Solid Flocculation and Emulsifying Activities of the Lipopolysaccharide Produced by Trichosporon mycotoxinivorans CLA2.
abstract: The objective of this study was to evaluate the capability of a lipopolysaccharide, produced by Trichosporon mycotoxinivorans CLA2 using residue of biodiesel processing, to flocculate two different solids in suspension. In addition, the emulsifying activity and the stability of this lipopolysaccharide in response to pH and temperature variations and in the presence of some electrolytes were evaluated. The lipopolysaccharide was used in concentrations ranging from 20 to 80 mgL-1to flocculate 100 gL-1of kaolin and 50 gL-1of charcoal. The results indicated that the flocculating capability for each suspended particles reached 80 % and 78.79 % after 14 min, respectively. Other tests indicated that the emulsifying activity is weakly affected by temperature, pH and NaCl. In addition, the surfactant activity was assessed by the droplet diameter method and tension surface measurement. The surface tension of pure water decreased gradually with an increase in the biopolymer concentration until a minimum of 52 m Nm-1with a CMC value of 4.54 mgL-1. These findings demonstrated a potential use of the bioemulsifier in flocculation and emulsification processes, which are also favored by its reduced toxicity compared to those of widely used commercial polymers.
authors.affiliation: Laboratory of Applied Microbiology, Department of Microbiology, Institute of Biological Science, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627 - Pampulha/ICB, Bloco F4, sala 159, Belo Horizonte, MG, C.P. 486, 31270-901, Brazil.
authors.forename: Vitor S
authors.initials: VS
authors.lastname: Domingues
authors.affiliation: Laboratory of Microbiology, Universidade CEUMA, R. Josué Montello, 1 - Renascença II, São Luís, MA, C.P. 65075120, Brazil.
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Monteiro
authors.affiliation: Departamento de Farmácia, Universidade Federal de Juiz de Fora, UFJF, Campus Governador Valadares - MG. Av. Dr. Raimundo Monteiro de Rezende 330, Centro, 35010-1 77, Governador Valadares, MG, Brazil. gabriella.freitas@ufjf.edu.br.
authors.forename: Gabriella Freitas
authors.initials: GF
authors.lastname: Ferreira
authors.affiliation: Laboratory of Applied Microbiology, Department of Microbiology, Institute of Biological Science, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627 - Pampulha/ICB, Bloco F4, sala 159, Belo Horizonte, MG, C.P. 486, 31270-901, Brazil.
authors.forename: Vera L
authors.initials: VL
authors.lastname: Santos
mesh_terms: D056804:Biofuels / Q000032:analysis; D002606:Charcoal / Q000737:chemistry; D045703:Emulsifying Agents / Q000737:chemistry* / Q000378:metabolism; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D007616:Kaolin / Q000737:chemistry; D007700:Kinetics; D008070:Lipopolysaccharides / Q000096:biosynthesis / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013500:Surface Tension; D013696:Temperature; D014250:Trichosporon / Q000378:metabolism*; D014867:Water / Q000737:chemistry
chemical_list: D056804:Biofuels; D045703:Emulsifying Agents; D008070:Lipopolysaccharides; D014867:Water; D002606:Charcoal; D007616:Kaolin; D012965:Sodium Chloride
keywords: Biodiesel residue; Bioemulsifier; Flocculation; Lipopolysaccharide