Ecological and Molecular Approach to the Assessment of Oil Pollution: A Comparative Study Between Two Coastal Marine (Mediterranean and Patagonian) Ecoregions

Abstract

Microorganisms are considered as sentinels of environmental changes, but microbial response to the presence of contaminants, such as hydrocarbons, is still not fully understood. This study aimed at assessing the response of the microbial community to the presence of oil pollution, by comparison of two ecosystems, Milazzo Gulf (Sicily, Italy) and Caleta Cordova (Argentina), as representative of two different temperate Mediterranean and cold-temperate Patagonian ecoregions, respectively. Water and sediments were sampled at coastal stations characterized by different levels of hydrocarbon contamination and analyzed for their microbial enzymatic activity rates; the presence of hydrocarbondegrading bacteria was also determined. The study approach allowed to determine that microbial metabolism was significantly reduced at the polluted stations, suggesting the detrimental effects of contaminants on organic matter degradation process. The isolation of strains of hydrocarbon-degrading bacteria confirmed that the oil contamination favoured the growth of strains specifically adapted to metabolize hydrocarbons and actively involved in the remediation processes.

Characterization of Five Psychrotolerant Alcanivorax spp. Strains Isolated from Antarctica

“…Sequences related to oil-degrading bacteria of the genera Alcanivorax and Marinobacter were also detected within the prokaryotic community colonizing some plastic fragments retrieved from the sub-Antarctic area of King George Island and the potential role of these microorganisms as plastic degraders was suggested [ 37 ]. Conversely, studies regarding the occurrence and ecology of OHCB in Antarctic seawater are quite scarce [ 38 ]; consequently, the present study confirms the presence of psychrotolerant hydrocarbon-degrading bacteria in Antarctic surface waters, widening knowledge about their ecophysiology.…”