Effects of nitrate treatment on a mixed species, oil field microbial biofilm.
Biofilms of bacteria, indigenous to oil field produced water, were grown in square section, glass capillary flow cells at 45 degrees C. Initially, in situ image analysis microscopy revealed predominantly coccoid bacteria (length-to-width ratio measurements (l (c):w (c)) of bacterial cells gave a mean value of 1.1), while chemical measurements confirmed sulphate reduction and sulphide production. After nitrate ion addition at 100 and 80 mg/l, in the two repeat experiments respectively, the dominance of rod-shaped bacteria (mean l (c):w (c) = 2.8) was observed. This coincided with the occurrence of nitrate reduction in the treated flow cells. Beneficially, no significant increase in biofilm cover was observed after the addition of nitrate. The dominant culturable nitrate-reducing bacterium was Marinobacter aquaeolei. The l (c):w (c) ratio measured here concurs with previously reported cell dimensions for this organism. Several Marinobacter strains were also isolated from different oil fields in the North Sea where nitrate treatment has been applied to successfully treat reservoir souring, implying that this genus may play an important role in nitrate treatment.
Oil Plus Ltd, Hambridge Road, RG14 5SS, Newbury, Berkshire, UK. B.Dunsmore@oilplus.co.uk
Braden
B
Dunsmore
James
J
Youldon
David R
DR
Thrasher
Ian
I
Vance
D034241:Alteromonadaceae / Q000145:classification / Q000302:isolation & purification; D001419:Bacteria / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D007091:Image Processing, Computer-Assisted; D008853:Microscopy; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D012988:Soil Microbiology; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism
D009566:Nitrates; D009573:Nitrites; D013431:Sulfates; D013440:Sulfides