Isolation And Identification Of Sulfate Reducing Bacteria In Oil-field

Currently,the increasing corrosion caused by sulfate-reducing bacteria in oilfield becomes more and more serious.The corrosion not only causes inconvenience to the oil transportation, but also makes huge economic losses. Therefore, it’s very importent to study the composition of the sulfate-reducing bacteria relationship and the regular pattern of their growth in the oilfield.And the study can help us reduce the corrosion caused by sulfate-reducing bactenais more effectively.In this study,we had learned the SRB community and completed the dsr gene clone library of the Jianghan oilfield and the Dagang oilfield.The water samples of Jianghan oilfield are "Guanghua filter","Wangchang filter","Entrance of Guanghua pump".The water samples of Dagang oilfield are "No process of Guanyi Union","Processed of Guanyi Union","Zhao12-13".A strain of SRB was isolated from "No process of Guanyi Union",and its physiological and biochemical characteristics were studied.In this study,our main results are as follows:(1)The dominant bacterial communities in the Jianghan oilfield water samles were Bacillus licheniformis and Bacillus subtilis.Bacillus licheniformis can produce surface activator, Bacillus subtilis can degrade dibenzothiophene.(2)The dominant bacterial communities in the Dagang oilfield water sarnles were all different from each other,while they had a same bacterial community named uncultured bactrial.The dominant bacterial communities in the "No process of Guanyi Union" were Desulfacinum infernum,unclassfied prokaryote,bacterium enrichment culture clone Dan60_dsr32E,bacterium enrichment culture clone Dan60_dsr31E and Thermodesulforhabdus norvegica.Their proportions were48.8%,19.2%,10.3%,7.7%and7.7%respectively.The dominant bacterial communities in the "Processed of Guanyi Union" were Desulfovibrio alkalitolerans,bacterium enrichment culture clone Dan60_dsr32E,Desulfacinum infernum,unclassfied prokaryote,Desulfomicrobium thermophilum and bacterium AR1902. Their proportion were26.8%,16.9%,12.7%,11.3%,7.0%and7.0%respectively. The dominant bacterial communities in the "Zhaol2-13" were Desulfovibrio alaskensis,Thermodesulforhabdus norvegica and uncultured prokaryote.Their proportion were82.2%,4.1%and5.5%respectively.(3)A strain of DG-S1was isolated from the "No process of Guanyi Union" of Dagang oilfield, phylogenetic analysis based on16S rDNA gene sequence indicated that strain DG-S1was affiliated with Desulfacinum infernum with a similarity of99%. (4)We had studied the physiological and biochemical characteristics of the strain.It showed it’s gram-negative,its optimum growth temperature is60℃,optimum growth solinity is1%,and optimum growth pH is7.5.Its G+C content is58.1mol%.Its main fatty acid include anteisoC15:0(30.5%), isoC15:0(25.39%), anteisoC17:0(18.86%), isoC17:0(12.85%), C16:0(4.41%), and isoC16:0(3.12%)...