油井采出液中硝酸盐还原菌的分离培养及对硫酸盐还原的抑制

采用油井采出液培养基和加入无机盐成分的改良油井采出液培养基,对大庆油田萨北过渡带油井采出液中的细菌进行分离培养及初步鉴定,比较了两种情况下培养出的具有硝酸盐和/或亚硝酸盐还原,以及/或反硝化能力菌群结构的差异.利用采出液培养基培养出一组新的微生物菌株,并且分离的硝酸盐和/或亚硝酸盐还原菌,以及/或反硝化细菌(Nitrate/nitrite reducing bacteria,denitrifying bacteria,NRDB)比例明显高于无机盐-采出液培养基;但培养基中无机盐成分的添加,提高了可培养NRDB的群落生物多样性.仅仅向油井采出液中直接投加硝酸盐作为电子受体,对其中硝酸盐还原、亚硝酸盐还原和反硝化微生物(NRDB)的激活作用以及产抑制硫化物产生的能力有限,而同时加入分离自采出液的NRDB和硝酸盐则对硫酸盐还原菌(SRB)的生长和产硫化物活性都产生了明显的抑制.但是NRDB与硝酸盐同时投加对不同SRB的抑制效果并不相同,导致了SRB群落结构的变化.图5表2参17

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