Abstract:

The rates of crude oil degradation by the extant microorganisms in intertidal sediments from a northern Gulf of Mexico beach were determined. The enhancement in crude oil degradation by amending the microbial communities with marine organic matter was also examined. Replicate mesocosm treatments consisted of: (i) controls (intertidal sand), (ii) sand contaminated with crude oil, (iii) sand plus organic matter, and (iv) sand plus crude oil and organic matter. Carbon dioxide (CO2) production was measured daily for 42 days and the carbon isotopic ratio of CO2 (13CO2) was used to determine the fraction of CO2 derived from microbial respiration of crude oil. Data set includes CO2 production rates, nutrient concentrations at the end of the 42 day experiment, δ13C of respired CO2, TPH concentrations at the end of 42 day experiment, as well as hydrocarbon degrader microbial numbers at the site and in the mesocosms after 42 days of exposure to crude oil.

Suggested Citation:

Behzad Mortazavi. 2014. Rates of petroleum hydrocarbon biodegradation in Gulf of Mexico sandy sediments and its enhancement by organic substrates. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N73X84MD

Publications:

Mortazavi, B., Horel, A., Beazley, M. J., & Sobecky, P. A. (2013). Intrinsic rates of petroleum hydrocarbon biodegradation in Gulf of Mexico intertidal sandy sediments and its enhancement by organic substrates. Journal of Hazardous Materials, 244-245, 537–544. doi:10.1016/j.jhazmat.2012.10.038

Purpose:

To examine how organic substrates can enhance the degradation of hydrocarbons in sandy sediments. Hydrocarbon mineralization was 76% higher in the crude oil amended with organic matter treatment compared to the rate in the crude oil only treatment indicating that biodegradation of crude oil in the intertidal zone by an extant microbial community is enhanced by input of organic matter.

Data Parameters and Units:

Daily CO2 production (mean ± Standard deviation) (mgC) Cumulative CO2 production (mean ± Standard deviation) (mgC) 13C of respired CO2 (isotope ratios stated in per mille difference from Vienna Pee Dee Belemnite, or VPDB) Nutrient concentrations (mg N/Kg of sediment or mg P/Kg of sediment) Total petroleuym hydrocarbons (mg/Kg of sediment) Hydrocarbon degrading microbial numbers (MPN/g dry weight sediment) where MPN means Most-probable-number method for determining the number of specific types of microorganisms in the sample

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