title: Effect of nitrate and nitrite on sulfide production by two thermophilic, sulfate-reducing enrichments from an oil field in the North Sea.
abstract: Thermophilic sulfate-reducing bacteria (tSRB) can be major contributors to the production of H(2)S (souring) in oil reservoirs. Two tSRB enrichments from a North Sea oil field, NS-tSRB1 and NS-tSRB2, were obtained at 58 degrees C with acetate-propionate-butyrate and with lactate as the electron donor, respectively. Analysis by rDNA sequencing indicated the presence of Thermodesulforhabdus norvegicus in NS-tSRB1 and of Archaeoglobus fulgidus in NS-tSRB2. Nitrate (10 mM) had no effect on H(2)S production by mid-log phase cultures of NS-tSRB1 and NS-tSRB2, whereas nitrite (0.25 mM or higher) inhibited sulfate reduction. NS-tSRB1 did not recover from inhibition, whereas sulfate reduction activity of NS-tSRB2 recovered after 500 h. Nitrite was also effective in souring inhibition and H(2)S removal in upflow bioreactors, whereas nitrate was similarly ineffective. Hence, nitrite may be preferable for souring prevention in some high-temperature oil fields because it reacts directly with sulfide and provides long-lasting inhibition of sulfate reduction.
authors.affiliation: International Research Institute of Stavanger (IRIS), Akvamiljø, Mekjarvik 12, Randaberg, Norway.
authors.forename: Krista M
authors.initials: KM
authors.lastname: Kaster
authors.forename: Alexander
authors.initials: A
authors.lastname: Grigoriyan
authors.forename: Gary
authors.initials: G
authors.lastname: Jenneman
authors.forename: Gary
authors.initials: G
authors.lastname: Jennneman
authors.forename: Gerrit
authors.initials: G
authors.lastname: Voordouw
mesh_terms: D019609:Archaeoglobus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020564:Deltaproteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D005648:Fuel Oils; D006358:Hot Temperature; D008969:Molecular Sequence Data; D009566:Nitrates / Q000494:pharmacology*; D009573:Nitrites / Q000494:pharmacology*; D009659:North Sea; D012623:Seawater / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism*; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D005648:Fuel Oils; D009566:Nitrates; D009573:Nitrites; D013431:Sulfates; D013440:Sulfides