Preliminary studies of naphthalene-degrading bacteria isolated from muelle storni sediments

RIVA MERCADAL JP; DELGADO O; DIONISI H; FERRERO M

BIOCELL

INST HISTOL EMBRIOL-CONICET

Año: 2005 vol. 29 p. 165 - 165

0327-9545

In order to isolate naphthalene-degrading bacteria from sediments of a highly contaminated site with polyaromatic hydrocarbons, three successive enrichment cultures were made in a synthetic marine media with 0.5 % naphthalene as a sole carbon and energy source. Growth was performed with agitation in darkness at 25ºC and 15ºC. After incubation, several colonies were isolated on agar plates at the different enrichment conditions. DGGE procedure was applied in order to compare the resulting biodiversity of culturable bacteria and ARDRA method to select potentially different species of bacteria for further identification. In a culture-independent approach, total DNA was purified from the same sediments, and alpha subunits of initial PAH-dioxygenase genes were amplified using a degenerate primer set, cloned and sequenced. All analyzed clones in the library were closely related to phnAc genes from the phenanthrene-degraders Burkholderia sp. Ch1-1, Ch3-5, Cs1-4 and Eh1-1 (AY367784-7; 99.5 to 99.8% similarity at the nucleotide level) and Alcaligenes faecalis AFK2 (AB024945; 95.7-95.9% similarity). The presence of these catabolic genes was also search on the isolated bacteria.