Original Research ARTICLE
High di-rhamnolipid production using Pseudomonas aeruginosa KT1115, separation of mono/di-rhamnolipids, and evaluation of their properties
- 1State Key Laboratory of Materials-Oriented Chemical Engineering, School of Materials Science and Engineering, Nanjing Tech University, China
- 2Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), China
Rhamnolipids (RLs) are important bioproducts that are regarded as promising biosurfactant for applications in oil exploitation, cosmetics and food industry. In this study, the newly isolated Pseudomonas aeruginosa KT1115 showed high production of di-RLs. The highest yield of RLs by P. aeruginosa KT1115, reaching 44.39 g/L after 8 days of fermentation in a 5 L bioreactor, was obtained from rapeseed oil-nitrate medium after process optimization. Furthermore, we established a new separation process that achieved up to 91.82% RLs recovery with a purity of 89% and further obtained mono/di-rhamnolipids. Finally, ESI-MS analysis showed that the RLs produced by strain KT1115 have a high proportion of di-RLs (mono-RLs : di-RLs = 11.47 : 88.53), which have a lower critical micelle-forming concentration (8 mN/m) and better emulsification ability with kerosene (52.1% EI24) than mono-RLs (167 mN/m and 41.4% EI24, respectively). These results demonstrated that P. aeruginosa KT1115 is a potential industrial producer of di-RLs, which have improved applicability and offer significant commercial benefits.
Keywords: CMC, Emulsifying activity, High-yielding, SEPARATION, di-rhamnolipids
Received: 10 Jul 2019;
Accepted: 13 Sep 2019.
Copyright: © 2019 Jie, Xue, Liu, Xu, Xin, Zhang, Jiang and Dong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mx. Weiliang Dong, State Key Laboratory of Materials-Oriented Chemical Engineering, School of Materials Science and Engineering, Nanjing Tech University, Nanjing, China, firstname.lastname@example.org