AUTHOR=Dong Hao , Xia Wenjie , Dong Honghong , She Yuehui , Zhu Panfeng , Liang Kang , Zhang Zhongzhi , Liang Chuanfu , Song Zhaozheng , Sun Shanshan , Zhang Guangqing 

TITLE=Rhamnolipids Produced by Indigenous Acinetobacter junii from Petroleum Reservoir and its Potential in Enhanced Oil Recovery

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01710

DOI=10.3389/fmicb.2016.01710

ISSN=1664-302X

ABSTRACT=<p>Biosurfactant producers are crucial for incremental oil production in microbial enhanced oil recovery (MEOR) processes. The isolation of biosurfactant-producing bacteria from oil reservoirs is important because they are considered suitable for the extreme conditions of the reservoir. In this work, a novel biosurfactant-producing strain <italic>Acinetobacter junii</italic> BD was isolated from a reservoir to reduce surface tension and emulsify crude oil. The biosurfactants produced by the strain were purified and then identified via electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS). The biosurfactants generated by the strain were concluded to be rhamnolipids, the dominant rhamnolipids were C<sub>26</sub>H<sub>48</sub>O<sub>9</sub>, C<sub>28</sub>H<sub>52</sub>O<sub>9</sub>, and C<sub>32</sub>H<sub>58</sub>O<sub>13</sub>. The optimal carbon source and nitrogen source for biomass and biosurfactant production were NaNO<sub>3</sub> and soybean oil. The results showed that the content of acid components increased with the progress of crude oil biodegradation. A glass micromodel test demonstrated that the strain significantly increased oil recovery through interfacial tension reduction, wettability alteration and the mobility of microorganisms. In summary, the findings of this study indicate that the newly developed BD strain and its metabolites have great potential in MEOR.</p>