Evidence for denitrification in marine sediment highly contaminated by petroleum products

Abstract

Denitrifying activity was measured in marine sediment (mediterranean coast of France) sampled near a petroleum refinery heavily contaminated by hydrocarbons (31 g kg −1 of sediment). Results provided evidence that in Lavera Bay sediment chronically polluted by petroleum products, denitrification (potential and estimated activities) was not affected by petroleum input and was comparable to those obtained in unpolluted sediments. However, due to low nitrate concentration natural denitrifying activity is not detectable. The dominant denitrifying bacteria (85% of the isolates) belonged to the genus Pseudomonas and four groups of bacteria could be discriminated. The growth pattern on nitrate was different for each isolate and one strain was not capable of nitrous oxide production.