Abstract

SALGADO-BERNAL, Irina et al. Rhizosphere bacteria with physiological potentialities for organic matter removal from waste waters. Rev. Int. Contam. Ambient [online]. 2012, vol.28, n.1, pp.17-26. ISSN 0188-4999.

The contamination of waters constitutes a serious environmental problem at the moment and within the interest polluting agents is effluent organic matter (EfOM), composed by complex and heterogenous elements, among them carbohydrates, proteins and fatty acids. Due to advantages that offers the use of biological agents for the elimination of these pollutants, in present work we characterized the potentialities of 58 bacterial strains, obtained from rhizosphere of hydrophytes (Typha dominguensis), for the removal of organic matter, with the purpose of being used later like tools in residual water treatment. Assimilation tests were performed with five carbohydrates, including monosaccharides, disaccharides and polysaccharides, hydrolysis tests for two proteins and hydrolysis of a lipidic compound. COD reduction was determined with 13 selected strains of a complex synthetic wastewater, individually and with bacterial consortia. 21 strains (36 % of isolates) showed satisfactory results to assimilate different carbon sources and hydrolyze proteins and lipids. Of these, 13 selected isolates showed COD removal levels above 50 % from a complex effluent in 72 hours, this result behaved similarly with the use of consortia formed by these strains. The results show that the studied strains could potentially be used for subsequent incorporation into a water treatment system and contribute to the remediation of effluents.

Keywords : rhizospheric bacteria; effluent organic matter; water treatment.