Resumo

CASTRO-CARRILLO, Luis Alfredo; DELGADILLO-MARTINEZ, Julián; FERRERA-CERRATO, Ronald  e  ALARCON, Alejandro. Phenanthrene dissipation by azolla caroliniana utilizing bioaugmentation with hydrocarbonoclastic microorganisms. INCI [online]. 2008, vol.33, n.8, pp.591-597. ISSN 0378-1844.

The aim of this work was to evaluate the ability of Azolla caroliniana to grow and to dissipate phenanthrene (PHE) by using bioaugmentation with hydrocarbonoclastic microorganisms. A. caroliniana was selected from four Mexican strains based on its tolerance to increasing concentrations of PHE. Afterwards, A. caroliniana was exposed to PHE concentrations of 20, 40 and 60mg·l^-1 and/or inoculated with the microbial consortium conformed by Bacillus stearothermophilus and Oscillatoria sp. (BST+OSC), strains previously tested for their tolerance to 100mg PHE·l^-1. After 49 days, the higher dry mass production was observed at the treatment with 20mg PHE and at that with BST+OSC in presence of 40mg PHE·l^-1; both treatments had 19.7% more dry mass than the control. Treatments with higher dry mass production also had higher nitrogenase activity (7-12nmolC₂H₄·g^-1·h^-1), whereas the lowest activity was observed at the treatments with 60mg PHE (3-4nmol C₂H₄·g^-1·h^-1). The lowest PHE dissipation (45%) was observed in A. caroliniana without BST+OSC in the presence of 20mg PHE; in contrast, the highest PHE dissipation (80%) was observed with A. caroliniana, either inoculated or not, when in presence of 60mg PHE. This is one of the first reports describing the negative effects of PHE on the growth of Azolla and its microsymbiont, as well as the potential of A. caroliniana for the dissipation of PHE with or without bioaugmentation.

Palavras-chave : Microorganismos Degradadores de HAP; Nitrogenasa; Remediación; Simbiosis.