Grigoryan Aleksandr A, Cornish Sabrina L, Buziak Brenton, Lin Shiping, Cavallaro Adriana, Arensdorf Joseph J, Voordouw Gerrit
Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
Appl Environ Microbiol. 2008 Jul;74(14):4324-35. doi: 10.1128/AEM.00419-08. Epub 2008 May 23.
Acetate, propionate, and butyrate, collectively referred to as volatile fatty acids (VFA), are considered among the most important electron donors for sulfate-reducing bacteria (SRB) and heterotrophic nitrate-reducing bacteria (hNRB) in oil fields. Samples obtained from a field in the Neuquén Basin, western Argentina, had significant activity of mesophilic SRB, hNRB, and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). In microcosms, containing VFA (3 mM each) and excess sulfate, SRB first used propionate and butyrate for the production of acetate, which reached concentrations of up to 12 mM prior to being used as an electron donor for sulfate reduction. In contrast, hNRB used all three organic acids with similar kinetics, while reducing nitrate to nitrite and nitrogen. Transient inhibition of VFA-utilizing SRB was observed with 0.5 mM nitrite and permanent inhibition with concentrations of 1 mM or more. The addition of nitrate to medium flowing into an upflow, packed-bed bioreactor with an established VFA-oxidizing SRB consortium led to a spike of nitrite up to 3 mM. The nitrite-mediated inhibition of SRB led, in turn, to the transient accumulation of up to 13 mM of acetate. The complete utilization of nitrate and the incomplete utilization of VFA, especially propionate, and sulfate indicated that SRB remained partially inhibited. Hence, in addition to lower sulfide concentrations, an increase in the concentration of acetate in the presence of sulfate in waters produced from an oil field subjected to nitrate injection may indicate whether the treatment is successful. The microbial community composition in the bioreactor, as determined by culturing and culture-independent techniques, indicated shifts with an increasing fraction of nitrate. With VFA and sulfate, the SRB genera Desulfobotulus, Desulfotignum, and Desulfobacter as well as the sulfur-reducing Desulfuromonas and the NR-SOB Arcobacter were detected. With VFA and nitrate, Pseudomonas spp. were present. hNRB/NR-SOB from the genus Sulfurospirillum were found under all conditions.
乙酸盐、丙酸盐和丁酸盐统称为挥发性脂肪酸（VFA），被认为是油田中硫酸盐还原菌（SRB）和异养硝酸盐还原菌（hNRB）最重要的电子供体之一。从阿根廷西部内乌肯盆地的一个油田采集的样本中，嗜温SRB、hNRB以及硝酸盐还原硫化物氧化细菌（NR-SOB）具有显著活性。在含有VFA（每种3 mM）和过量硫酸盐的微观世界中，SRB首先利用丙酸盐和丁酸盐生成乙酸盐，在乙酸盐被用作硫酸盐还原的电子供体之前，其浓度可达12 mM。相比之下，hNRB以相似的动力学利用所有三种有机酸，同时将硝酸盐还原为亚硝酸盐和氮气。观察到0.5 mM亚硝酸盐会对利用VFA的SRB产生短暂抑制，而浓度为1 mM或更高时会产生永久性抑制。向流入装有已建立的VFA氧化SRB菌群的上流填充床生物反应器的培养基中添加硝酸盐，会导致亚硝酸盐峰值高达3 mM。亚硝酸盐介导的对SRB的抑制反过来又导致乙酸盐短暂积累高达13 mM。硝酸盐的完全利用以及VFA（尤其是丙酸盐）和硫酸盐的不完全利用表明SRB仍受到部分抑制。因此，除了较低的硫化物浓度外，在注入硝酸盐的油田产出水中，硫酸盐存在时乙酸盐浓度的增加可能表明处理是否成功。通过培养和非培养技术确定的生物反应器中的微生物群落组成表明，随着硝酸盐比例的增加会发生变化。在有VFA和硫酸盐的情况下，检测到了SRB属的脱硫芽孢杆菌属、脱硫木菌属和脱硫杆菌属以及硫还原菌脱硫单胞菌属和NR-SOB嗜盐弧菌属。在有VFA和硝酸盐的情况下，存在假单胞菌属。在所有条件下都发现了来自硫螺旋菌属的hNRB/NR-SOB。
