Biosurfactant production by Pseudomonas strains isolated from floral nectar

Z Ben Belgacem; S Bijttebier; C Verreth; S Voorspoels; I Van de Voorde; G Aerts; K A Willems; H Jacquemyn; S Ruyters; B Lievens

doi:10.1111/jam.12799

Biosurfactant production by Pseudomonas strains isolated from floral nectar

J Appl Microbiol. 2015 Jun;118(6):1370-84. doi: 10.1111/jam.12799. Epub 2015 Apr 22.

Authors

Affiliations

¹ Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems (M2S), KU Leuven, Campus De Nayer, Sint-Katelijne Waver, Belgium.
² Flemish Institute for Technological Research (VITO), Business Unit Separation and Conversion Technology (SCT), Mol, Belgium.
³ Laboratory of Enzyme, Fermentation, and Brewing Technology, Department of Microbial and Molecular Systems (M2S), KU Leuven, Campus KaHo Sint-Lieven, Ghent, Belgium.
⁴ Division of Plant Ecology and Systematics, Biology Department, KU Leuven, Leuven, Belgium.

PMID: 25801599
DOI: 10.1111/jam.12799

Abstract

Aims: To screen and identify biosurfactant-producing Pseudomonas strains isolated from floral nectar; to characterize the produced biosurfactants; and to investigate the effect of different carbon sources on biosurfactant production.

Methods and results: Four of eight nectar Pseudomonas isolates were found to produce biosurfactants. Phylogenetic analysis based on three housekeeping genes (16S rRNA gene, rpoB and gyrB) classified the isolates into two groups, including one group closely related to Pseudomonas fluorescens and another group closely related to Pseudomonas fragi and Pseudomonas jessenii. Although our nectar pseudomonads were able to grow on a variety of water-soluble and water-immiscible carbon sources, surface active agents were only produced when using vegetable oil as sole carbon source, including olive oil, sunflower oil or waste frying sunflower oil. Structural characterization based on thin layer chromatography (TLC) and ultra high performance liquid chromatography-accurate mass mass spectrometry (UHPLC-amMS) revealed that biosurfactant activity was most probably due to the production of fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof.

Conclusions: Four biosurfactant-producing nectar pseudomonads were identified. The active compounds were identified as fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof, produced by hydrolysis of triglycerides of the feedstock.

Significance and impact of the study: Studies on biosurfactant-producing micro-organisms have mainly focused on microbes isolated from soils and aquatic environments. Here, for the first time, nectar environments were screened as a novel source for biosurfactant producers. As nectars represent harsh environments with high osmotic pressure and varying pH levels, further screening of nectar habitats for biosurfactant-producing microbes may lead to the discovery of novel biosurfactants with broad tolerance towards different environmental conditions.

Keywords: Pseudomonas sp; biosurfactant; fatty acids; nectar; surface tension.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

DNA, Bacterial / genetics
Flowers / chemistry
Flowers / microbiology*
Molecular Sequence Data
Phylogeny
Plant Nectar / chemistry*
Pseudomonas / classification
Pseudomonas / genetics
Pseudomonas / isolation & purification
Pseudomonas / metabolism*
RNA, Ribosomal, 16S / genetics
Surface-Active Agents / chemistry
Surface-Active Agents / metabolism*

Substances

DNA, Bacterial
Plant Nectar
RNA, Ribosomal, 16S
Surface-Active Agents

Associated data

GENBANK/KM190903
GENBANK/KM190926