Bacteriology of a Gulf of Mexico gas and oil field

Abstract

From the Abstract: “A three year study of the bacteriology of a 20 year old active gas and oil field in the Gulf of Mexico has been completed. The bacterial community of the production platform area was in general identical to the control site. Taxonomic groups and genera diversity were essentially the same for the two sites. The bacterial population around the platforms did show some adaptation, especially to the materials released from the platforms. A higher percentage of sulfur utilizing and oil degrading bacteria were found in the immediate area of the platform than at the control site. Bacterial strains from the platforms also appeared adapted to growth in the brine discharge released by the platform. Concentrations of brine discharge, which inhibit growth or activity of laboratory cultures and strains from the control site, did not affect bacteria from the platform site. Isolates from the platform area when suspended in diluted brine discharge grew, exhibited chemotatic responses, and attached to glass surfaces.

Brine discharge did not appear to be a significant bacterial nutrient in the platform area. Bacterial numbers and biomass were slightly iower in the platform area than at the control site. Sulfur oxidizing bacteria were generally Pseudomonas sp. rather than obligate autotrophic Thiobacillus sp. Bacterial strains which could utilize brine discharge hydrocarbons were found around the platform. Some strains and mixed cultures from the platform area could readily utilize most platform released hydrocarbons. However, these strains only represented a very small portion of the total bacterial populations.

In general, the differences between the bacteriology of the platform area and the control site were less than the difference seen between samples collected from different depths or seasons at the control site.”