Metagenomics reveals the high polycyclic aromatic hydrocarbon-degradation potential of abundant uncultured bacteria from chronically polluted subantarctic and temperate coastal marine environments

LOVISO, CLAUDIA L.; LOZADA, MARIANA; GUIBERT, LILIAN; MUSUMECI, MATIAS; SARANGO, SANDRA; KUIN, RUUD; MARCOS, MAGALÍ S.; DIONISI, HEBE M.

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 119 p. 411 - 424

1364-5072

p { margin-bottom: 0.25cm; line-height: 120%; }AbstractAimsTo investigate the potential to degradepolycyclic aromatic hydrocarbons (PAHs) of yet-to-be-culturedbacterial populations from chronically polluted intertidal sediments.Methods and ResultsA gene variant encoding the alphasubunit of the catalytic component of an aromatic-ring-hydroxylatingoxygenase (RHO) was abundant in intertidal sediments from chronicallypolluted subantarctic and temperate coastal environments, and itsabundance increased after PAH amendment. Conversely, this marker genewas not detected in sediments from a nonimpacted site, even after ashort-term PAH exposure. A metagenomic fragment carrying this genevariant was identified in a fosmid library of subantarctic sediments.This fragment contained five pairs of alpha and beta subunit genesand a lone alpha subunit gene of oxygenases, classified as belongingto three different RHO functional classes. In silico structuralanalysis suggested that two of these oxygenases contain largesubstrate-binding pockets, capable of accepting high molecular weightPAHs.ConclusionsThe identified unculturedmicro-organism presents the potential to degrade aromatichydrocarbons with various chemical structures, and could represent animportant member of the PAH-degrading community in these pollutedcoastal environments.Significance and Impact of the StudyThis work provides valuable informationfor the design of environmental molecular diagnostic tools and forthe biotechnological application of RHO enzymes.