Abstract
Objective. To isolate biosurfactant-producing microorganisms from the rhizosphere of fique and to select the best genus to evaluate the effect of nutritional and fermentation conditions on the production of rhamnolipids. Materials and methods. Rhizospheric soil was sampled in three areas of Cauca. The best genus was selected for the experimental designs (Plackett Burman and 22 factorial) and to find the production conditions for the growth kinetics at an Erlenmeyer flask scale. Results. Isolates from the rhizosphere of fique plants were from groups (or genera) of Bacillus, Pseudomonas and Streptomyces, being Pseudomonas the more responsive in preliminary testing for emulsification. From the results of the experimental designs and the kinetics of production, we found that rhamnose synthesis associated with rhamnolipids (3.2 g/l) and emulsification (68% EC24) was significantly favored (p <0.0001) by cultivating an inoculum of 10% v/v of Pseudomonas fluorescens in a medium composed of: soybean oil 2% (v/v), K2HPO4 0.2% (w/v), yeast extract 0.4 g/l, NH4NO3 3.7 g/l, 1 ml trace elements (CoCl3 20 mg/l, H3BO3 30 mg/l, ZnSO4 10 mg/l, Cu2SO4 1 mg/l, Na2MoO4 3 mg/l, FeSO4 10 mg/l MnSO4 2,6 mg/l) and pH 7.2. Conclusion. Of all the microbial genera isolated from the rhizosphere of fique, Pseudomonas fluorescens had the greatest potential in the production of biosurfactants of the rhamnolipids family.
Key words: Pseudomonas fluorescens, biosurfactant, rhamnose, emulsification index, soybean oil.
Univ. Sci. is registered under a Creative Commons Attribution 4.0 International Public License. Thus, this work may be reproduced, distributed, and publicly shared in digital format, as long as the names of the authors and Pontificia Universidad Javeriana are acknowledged. Others are allowed to quote, adapt, transform, auto-archive, republish, and create based on this material, for any purpose (even commercial ones), provided the authorship is duly acknowledged, a link to the original work is provided, and it is specified if changes have been made. Pontificia Universidad Javeriana does not hold the rights of published works and the authors are solely responsible for the contents of their works; they keep the moral, intellectual, privacy, and publicity rights. Approving the intervention of the work (review, copy-editing, translation, layout) and the following outreach, are granted through an use license and not through an assignment of rights. This means the journal and Pontificia Universidad Javeriana cannot be held responsible for any ethical malpractice by the authors. As a consequence of the protection granted by the use license, the journal is not required to publish recantations or modify information already published, unless the errata stems from the editorial management process. Publishing contents in this journal does not generate royalties for contributors.