FACTORS THAT INFLUENCE METHANOGENIC ACTIVITIES IN A LOW SULFATE OIL-PRODUCING FACILITY

Abstract

Molecular analysis of a low sulfate oil bearing environment was carried out using 16S rRNA gene sequencing technique and the effects of some environmental factors like pH, temperature, salinity on methane production and corrosion rates were determined. Pyrosequenced data revealed dominance of hydrogenotrophic (Methanobacterium) andMethylotrophic (Methanolobus) in samples. Results showed that samples had their optimal temperature for maximum methane production at 35–40oC and higher temperature (55oC) was inhibitory to methane production. Methanogens in samples produced methane over a wide pH range but the pH optima for maximum methane production ranged between 6 and 7. Sodium chloride was tolerated better at lower concentrations (<200mM), higher concentrations (>300mM) drastically inhibitedmethane formation, an indication that themethanogens involved are not halophytes. Because different methanogens require different substrates and reacts to changes in environmental conditions, environmental factorsmay indirectly control the diversity and activity of methanogens in low sulfate oil bearing environments.