Characterization of aerobic polycyclic aromatic hydrocarbon-degrading bacteria from Bizerte lagoon sediments, Tunisia

Abstract

Aims: To characterize polycyclic aromatic hydrocarbon (PAH)‐degrading bacteria from sediments of the Bizerte lagoon, and to determine their ability to resist other pollutants such as antibiotics and heavy metals. Methods and Results: More than 100 strains were isolated for their ability to use fluoranthene as the sole carbon and energy source. Most of them showed antibiotic and heavy metal resistance; 20 representative strains were selected for further analysis. 16S rRNA coding sequences analysis showed that the majority of the selected bacteria (75%) were affiliated to the Gammaproteobacteria. The selected strains also utilized high molecular weight PAHs containing up to four benzene rings and showed different profiles of PAH substrate usage suggesting different PAH degradation pathways. These results are consistent with the fact that nah‐like genes and idoA‐like genes, involved in PAH degradation, were detected in 6 and 1 strains respectively. Conclusions: The Bizerte lagoon, polluted by many human activities, leads to the co‐selection of strains able to cope with multiple contaminants. Significance and Impact of the Study: Polluted areas are often characterized by the concomitant presence of organic pollutants, heavy metals and antibiotics. This study is one of the first showing bacterial strains adapted to multiple contaminants, a promising potential for the development of bioremediation processes.

Étude expérimentale de l’évolution en microcosme du chrome (VI) dans l’eau de mer et de ses effets sur la macrofaune et les bactéries indigènes de la Lagune de Bizerte (Tunisie)

“…L'apport continu de polluants a très certainement favorisé la sélection et l'adaptation des bactéries à ces produits délétères et leur a permis, dans notre cas, d'acquérir une résistance à certains métaux tel le chrome, le métal étudié, ce qui explique la charge élevée en bactéries (BEN SAID et al, 2008).…”

Molecular Analyses of Microbial Activities Involved in Bioremediation

“…Ben Said et al ( 2008 ) characterized polycyclic aromatic hydrocarbon (PAH)-degrading bacteria from sediments of the Bizerte lagoon in presence of multiple contaminants such as organic pollutants, heavy metals and antibiotics. This study highlights the need of bacterial strains to be adapted to multiple contaminants to become a promising potential for bioremediation processes.…”

Characterization of Rhizobium naphthalenivorans sp. nov. with special emphasis on aromatic compound degradation and multilocus sequence analysis of housekeeping genes

“…One of the most characteristic features of the isolates is growth by degrading naphthalene as the sole substrate. Although some reports have shown that limited members of Rhizobium have a potential of aromatic hydrocarbon degradation (Ben Said et al, 2008;Sanchez et al, 2005), none of the established Rhizobium species have been described for this trait. To our knowledge, therefore, this paper is the fi rst to offi cially describe a Rhizobium species capable of growing with naphthalene as the sole carbon and energy source.…”

“…While limited information has been available on the potential degradation of aromatic hydrocarbon by members of the genus Rhizobium (Ben Said et al, 2008;Sanchez et al 2005), our Rhizobium isolates were able to utilize naphthalene as the sole carbon and energy source and to degrade biphenyl and dibenzofuran co-metabolically. A genomic DNA region covering a gene encoding putative aromatic-ring-hydroxylating oxygenase (AhDO) in one of the isolates was cloned and identifi ed (Kaiya et al, 2012).…”