Isolation of Nitrate Reducing Bacteria from Oilfield Produced Water and Their Inhibition to Sulfate Reduction

Bacteria were cultivated and isolated with two different media from the oil well produced water in Sabei, Daqing Oil Field. The capabilities of nitrate reduction, nitrite reduction, denitrification and inhibition of sulfate reduction were compared between the two groups of bacteria isolated by the two media. With the medium only containing the water produced from oil well, a group of uncultivated bacteria were selected, and they could conduct N reduction and produce more bacterial isolates. The second medium containing the oil well produced water amended with inorganic salts resulted in few populations of nitrate/nitrite reducing bacteria or denitrifying bacteria (NRDB), but more species. Only nitrate could not remarkably stimulate nitrate reducing bacteria (NRB), which in turn could not inhibit the sulfide producing ability of the sulfate reducing prokaryotes (SRB). Contrarily, simultaneous introduction of the cultivated NRB and nitrate dramatically inhibited the sulfide production, reduced the total SRB amount, as well as changed the SRB community structure, showing different effects on the different SRB. Fig 5, Tab 2, Ref 17