Degradation of linear alkylbenzene sulfonate by a bacterial consortium isolated from the aquatic environment of Argentina.

AIMS

To isolate and identify linear alkylbenzene sulfonate (LAS)-degrading bacteria from Río de la Plata and adjacent waters, and to assay their degradation capability as a consortium and as single organisms.

METHODS AND RESULTS

A consortium consisting of four bacterial strains: Aeromonas caviae (two strains), Pseudomonas alcaliphila and Vibrio sp. was identified by 16S rRNA analysis. Isolates grown as a consortium produced higher biomass from LAS and CO(2) release (mineralization) than individual cultures, and degraded 86% of LAS (20 mg l(-1)), whereas pure strains degraded between 21% and 60%. Bacterial desulfonation from LAS was evidenced in the consortium and A. caviae strains. A complete disappearance of LAS (10 mg l(-1)) was accomplished, and LAS levels of 50 and 100 mg l(-1) led to a pronounced decrease in the biodegradation extent and inhibition of culture growth.

CONCLUSIONS

A bacterial consortium capable of complete LAS degradation was isolated from the Río de la Plata and adjacent waters. This consortium was more efficient for LAS degradation than individual cultures, and was sensitive to high LAS concentrations.

SIGNIFICANCE AND IMPACT OF THE STUDY

The autochthonous consortium with high effectiveness on LAS biodegradation is a useful tool for LAS depletion from these polluted ecosystems.