Enhanced biodegradation of diesel oil by a newly identified Rhodococcus baikonurensis EN3 in the presence of mycolic acid.
OBJECTIVE
The aim of the present study was to isolate and characterize a bacterium, strain EN3, capable of using diesel oil as a major carbon and energy source, and to analyse the enhancement of diesel oil degradation by this organism using synthetic mycolic acid (2-hexyl-3-hydroxyldecanoic acid).


RESULTS
An actinomycete with the ability to degrade diesel oil was isolated from oil contaminated soil and characterized. The strain had phenotypic properties consistent with its classification in the genus Rhodococcus showing a 16S rRNA gene similarity of 99.7% with Rhodococcus baikonurensis DSM 44587(T). The ability of the characterized strain to degrade diesel oil at various concentrations (1000, 5000, 10 000 and 20 000 mg l(-1)) was determined. The effect of synthetic mycolic acid on the biodegradation of diesel oil was investigated at the 20 000 mg l(-1) concentration; the surfactant was added to the flask cultures at three different concentrations (10, 50 and 100 mg l(-1)) and degradation followed over 7 days. Enhanced degradation was found at all three concentrations of the surfactant. In addition, the enhancement of diesel oil degradation by other surfactants was observed.


CONCLUSIONS
The synthetic mycolic acid has potential for the remediation of petroleum-contaminated sites from both an economic and applied perspective as it can stimulate biodegradation at low concentrations.


CONCLUSIONS
This study showed that the synthesized mycolic acid can be used for potential applications in the bioremediation industries, for example, in oil spill clean-up, diesel fuel remediation and biostimulation.
Lee
M
M
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea. e_stlee@kaist.ac.kr
Kim
M K
MK
Singleton
I
I
Goodfellow
M
M
Lee
S-T
ST
D001673:Biodegradation, Environmental / Q000187:drug effects; D003470:Culture Media; D005742:Gasoline; D005798:Genes, Bacterial / Q000235:genetics; D009171:Mycolic Acids / Q000494:pharmacology*; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012240:Rhodococcus / Q000235:genetics / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013501:Surface-Active Agents / Q000494:pharmacology*
D003470:Culture Media; D005742:Gasoline; D009171:Mycolic Acids; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D013501:Surface-Active Agents; C513423:2-hexyl-3-hydroxydecanoic acid