Among 64 bacterial strains isolated in this study, the best two of biosurfactant-producing bacteria were selected and identified based on the phenotypic properties and molecular approach based on 16S rRNA having 100% similarity to the gram-negative Enterobacter aerogenes B19 strain bacteria and rode gram-positive strain Bacillus cereus ISU-02 in the Nucleotide database of the National Center for Biotechnology Information. The study showed that two selected isolates gave the highest positive results that were used to investigate the biosurfactant production including: interfacial reduction, foaming activity, hemolytic activity, CTAB agar plate, drop collapse assay, oil displacement test and emulsification index E24%. Both Bacillus cereus ISU-02 strain and Enterobacter aerogenes B19 strain have reduced the interfacial tension to 27.61 and 28.93, respectively. Biosurfactants produced from both isolates were tested for oil recovery using spontaneous imbibition process. Bacillus cereus ISU-02 strain gave the highest oil recovery of 66.9% for rock permeability of 843 mD, followed by Enterobacter aerogenes B19 strain with oil recovery of 34% for rock permeability 197 mD, while the lowest rate of oil recovery was 12.1% for FW with permeability of 770 mD. An additional oil rate reached to 7.9% has been recovered from the residual oil when the core plug that was treated with formation water alone was retreated with the cell free biosurfactant supernatant. Use of the new biosurfactants has improved oil recovery better than use of formation water alone or formation water with the commercial surfactant SDS.

在这项研究中分离出的64个细菌菌株中，基于表型特性和基于16S rRNA的分子方法和与革兰氏阴性产气肠杆菌B19菌株细菌和杆状细菌100％相似的分子方法，选择并鉴定了最好的两种生物表面活性剂产生细菌国家生物技术信息中心核苷酸数据库中的蜡样芽孢杆菌阳性芽孢杆菌ISU-02。研究表明，所选择的两种分离物给出了最高的阳性结果，用于研究生物表面活性剂的产生，包括：界面还原，起泡活性，溶血活性，CTAB琼脂平板，滴落塌陷测定，驱油试验和乳化指数E24％。既蜡状芽孢杆菌ISU-02的应变和产气肠杆菌B19菌株已将界面张力分别降低至27.61和28.93。使用自发吸收过程测试了从两种分离物中产生的生物表面活性剂的油回收率。蜡状芽孢杆菌ISU-02菌株的最高石油采收率为66.9％，岩石渗透率为843 mD，其次是产气肠杆菌岩石渗透率197 mD的B19品系的采油率为34％，而渗透率为770 mD的FW的最低采油率为12.1％。当仅用地层水处理过的岩心塞用无细胞生物表面活性剂上清液进行处理时，可以从残留油中回收到高达7.9％的含油率。与单独使用地层水或与商业表面活性剂SDS一起使用地层水相比，使用新的生物表面活性剂具有更好的采收率。