Strategies for improved rhamnolipid production by Pseudomonas aeruginosa PA1

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1 Department of Basic Science / Faculty of Biological Science and Health, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil
2 Department of Biochemical Engineering / School of Chemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
3 Department of Biochemistry / Institute of Chemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
DOI
10.7287/peerj.preprints.1442v1
Published
Accepted
Subject Areas
Biotechnology, Microbiology
Keywords
rhamnolipid, biosurfactant, Pseudomonas aeruginosa, homoserine lactones
Copyright
© 2015 Soares dos Santos et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
Cite this article
Soares dos Santos A, Pereira Jr N, Freire DMG. 2015. Strategies for improved rhamnolipid production by Pseudomonas aeruginosa PA1. PeerJ PrePrints 3:e1442v1

Abstract

Rhamnolipids are biosurfactants with potential for diversified industrial and environmental uses. The present study evaluated three strategies to increase the production of rhamnolipid-type biosurfactants produced by Pseudomonas aeruginosa strain PA1. The influence of pH, the addition of endogenous autoinducers and the use of a fed batch process were examined. The culture medium adjusted to pH 7.0 was the most productive. Furthermore, the pH of the culture medium had a measurable effect on the ratio of mono- and dirhamnolipids synthesized. At pH values below 7.3, the proportion of monorhamnolipids decreased from 45 to 24%. Additionally, recycling 20% of the spent culture medium where P. aeruginosa was grown up to the later stationary phase was responsible for a 100% increase in rhamnolipid volumetric productivity in the new culture medium. Finally, the use of fed batch operation under conditions of limited nitrogen resulted in a 3.8-fold increase in the amount of rhamnolipids produced (1.29 g L-1 to 4.90 g L-1, as rhamnose). These results offer promising paths to optimize processes for the production of rhamnolipids.

Author Comment

This is a submission to PeerJ for review.

Supplemental Information

This archive contains raw data used to prepare the manuscript

DOI: 10.7287/peerj.preprints.1442v1/supp-1