Isolation and characterization of hydrocarbonoclastic bacteria from Algerian coast

Abstract

Backgrounds The contamination of marine environments by hydrocarbons represents a global concern with consequences on ecosystems and human health. The removal of HC by physical and/or chemical methods is expensive and disrespectful of the environment. The use of HC degrading bacteria is a good alternative for environmental remediation (bioremediation). Objectives The Algerian coastline is exposed to several types of pollutions, including hydrocarbons. The aim was to explore the bioremediation potential of its contaminated harbors for the first time. Methods To identify the hydrocarbon degrading bacteria seawater samples were collected in Sidi fredj harbor (Algeria) and used to enrichment cultures on mineral medium supplemented with Algerian light crude oil. The isolates were characterized by biochemical tests and Gram straining. The taxonomic identification of the isolates was performed by ARDRA and sequencing of the 16S rRNA gene. The ability to grow on hydrocarbons and degradation abilities were analysed by GC-FID together with their emulsification capacity. The key catabolic genes involved in HC degradation were detected by PCR. Conclusions About twenty isolates were assigned to known hydrocarbonoclastic genera (Alcanivorax, Halomonas, Marinobacter) and generalist HC degraders (Pseudomonas), but also to Bizionia (class Flavobacteriia). The isolates grow on n-alkanes (C16 to C24, Alcanivorax, Halomonas ) toluene and benzene (Marinobacter) and a show average oil emulsification capacity. The PCR and sequencing of catabolic genes confirmed the presence of alkane hydroxylase genes and degradation abilities analysis is in progress. Further characterization will allow us to identify the most interesting strains to perform bioremediation.