Engineered marine Antarctic bacterium Pseudoalteromonas haloplanktis TAC125: a promising micro-organism for the bioremediation of aromatic compounds

Aims: The recombinant Antarctic Pseudoalteromonas haloplanktis TAC125(P. haloplanktis TAC ⁄ tou) expressing toluene-o-xylene monooxygenase (ToMO)can efficiently convert several aromatic compounds into their correspondingcatechols in a broad range of temperature. When the genome of P. haloplanktisTAC125 was analysed in silico, the presence of a DNA sequence coding for aputative laccase-like protein was revealed. It is well known that bacterial lac-cases are able to oxidize dioxygenated aromatic compounds such as catechols.Methods and Results: We analysed the catabolic features, conferred by recom-binant ToMO activity and the endogenous laccase enzymatic activity, ofP. haloplanktis TAC ⁄ tou engineered strain and its ability to grow on aromaticcompounds as sole carbon and energy sources.Conclusions: Results presented highlight the broad potentiality of P. haloplank-tis TAC ⁄ tou cells expressing recombinant ToMO in bioremediation and suggestthe use of this engineered Antarctic bacterium in the bioremediation of chemi-cally contaminated marine environments and ⁄ or cold effluents.Significance and Impact of the Study: This paper demonstrates the possibilityto confer new and specific degradative capabilities to a bacterium isolated froman unpolluted environment (Antarctic seawater) transforming it into a bacte-rium able to grow on phenol as sole carbon and energy source.