The Deepwater Horizon spill in the Gulf of Mexico had a profound impact on the Gulf Coast marshes. An understanding of how indigenous oil-degrading bacteria respond to oil exposure is important for the remediation and management of oil-contaminated marshes. 

To understand the oil-degrading bacterial effects, quantification the abundance of oil-degrading bacterial populations and their functional gene expression should be developed to determine the responses of indigenous oil-degrading bacteria to oil exposure. 

Dr. WANG Jiaoyue, a researcher at Institute of Applied Ecology, Chinese Academy of Sciences, together with her companions, evaluated the effects of oil exposure on indigenous oil-degrading bacteria in Phragmites australis dominated marsh soil by a greenhouse mesocosm study. 

Through soil characteristics and oil-degrading bacteria population analysis, they found that oil exposure increased oil-degrading bacterial populations, in particular Gram-positive (GP) PAH-degraders.

Oiling also significantly increased the expression of oil-degrading genes; GP bacteria were the primary drivers in PAH degradation, accounting for approximately 98% of total detected genes.

Oil exposure enhanced soil respiration rate, DOC concentration and aromaticity of DOC, but decreased Eh values; GP PAH-RHDα genes were significantly related to the values of SUVA₂₅₄. 

The study entitled "The responses of indigenous oil-degrading bacteria to oil exposure in Phragmites australis dominated marsh soil: a mesocosm study" has been accepted in Hydrobiologia. 

This research is financially supported by The Gulf of Mexico Research Initiative (GoMRI), BP/GoMRI through the Northern Gulf Institute, and National Natural Science Foundation of China.