Isolation and Characterization of a Crude Oil-Tolerant Obligate Halophilic Bacterium from the Great Salt Lake of the United States of America

TL;DR

A salt-loving bacterium from the Great Salt Lake was found to tolerate crude oil but not break it down, suggesting potential for genetic modification in oil spill cleanup.

Contribution

A novel crude oil-tolerant obligate halophile, Salinivibrio costicola, was isolated and characterized for bioremediation potential.

Findings

The strain survives on desiccated agar for a year and grows in media with 0.1–1% crude oil.

The genome contains 3197 genes, including some potentially involved in hydrocarbon metabolism.

The strain does not reduce total recoverable petroleum hydrocarbons from crude oil.

Abstract

Most large-scale crude oil spills occur in marine environments. We screened easily propagable/maintainable halophiles to develop agents for the bioremediation of marine spills. A bacterial strain isolated from a polluted region of the Great Salt Lake was characterized and tested for its ability to degrade crude oil. The strain (Salinivibrio costicola) is motile, catalase- and lipase-positive, a facultative anaerobe, and an obligate halophile. Its growth optimum and tolerance ranges are: NaCl (5%, 1.25–10%), pH (8, 6–10), and temperature (22 °C, 4–45 °C). Its genome (3,166,267 bp) consists of two circular chromosomes and a plasmid, containing 3197 genes, including some genes potentially relevant to hydrocarbon metabolism. The strain forms a biofilm but is considered nonpathogenic and is sensitive to some common antibiotics. Lytic bacteriophages infecting the strain are rare in the water samples we tested. The strain survived on desiccated agar media at room temperature for a year, grew optimally in complex media containing 0.1–1% crude oil, but failed to reduce total recoverable petroleum hydrocarbons from crude oil. Thus, a recalcitrant halophile may endure crude oil without mineralizing. Due to some of their advantageous attributes, such strains can be considered for genetic manipulation to develop improved agents for bioremediation.

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