Isolation of a nitrate-reducing bacteria strain from oil field brine and the inhibition of sulfate-reducing bacteria

Abstract

A nitrate-reducing bacteria (NRB) strain with vigorous growth, strong nitrate reduction ability, strain B9 2-1, was isolated from Suizhong36-1 oilfield, its routine identification and analysis of 16S rRNA and also the competitive inhibition experiments with the enrichment of sulfate-reducing bacteria (SRB) were carried out. The results showed that only the dosing of nitrate, nitrite as electron acceptors, the activation of nitrate-reducing bacteria, as well as the inhibition of sulfide production resulted from a limited capacity, while addition of NRB isolated from the produced fluid, growth and sulfide production activity of sulfate reducing bacteria produced a significant inhibition and antibacterial effects of nitrite, which was better than nitrate. At the same time, the small amount of molybdate dosing showed better results, which will be of significance when applied to shipping and state-defending industries.

Key words: Nitrate-reducing bacteria, sulfate-reducing bacteria, restriction fragment length polymorphism, nitrates, nitrite, oil field, competitive inhibition.