A novel biosurfactant produced by Aureobasidium pullulans L3-GPY from a tiger lily wild flower, Lilium lancifolium Thunb.

Jong Shik Kim,In Kyoung Lee,Bong Sik Yun,Chenyu Du

doi:10.1371/journal.pone.0122917

Abstract

Yeast biosurfactants are important biotechnological products in the food industry, and they have medical and cosmeceutical applications owing to their specific modes of action, low toxicity, and applicability. Thus, we have isolated and examined biosurfactant-producing yeast for various industrial and medical applications. A rapid and simple method was developed to screen biosurfactant-producing yeasts for high production of eco-friendly biosurfactants. Using this method, several potential niches of biosurfactant-producing yeasts, such as wild flowers, were investigated. We successfully selected a yeast strain, L3-GPY, with potent surfactant activity from a tiger lily, Lilium lancifolium Thunb. Here, we report the first identification of strain L3-GPY as the black yeast Aureobasidium pullulans. In addition, we isolated a new low-surface-tension chemical, designated glycerol-liamocin, from the culture supernatant of strain L3-GPY through consecutive chromatography steps, involving an ODS column, solvent partition, silica gel, Sephadex LH-20, and an ODS Sep-Pak cartridge column. The chemical structure of glycerol-liamocin, determined by mass spectrometry and nuclear magnetic resonance spectroscopy, indicates that it is a novel compound with the molecular formula C33H62O12. Furthermore, glycerol-liamocin exhibited potent biosurfactant activity (31 mN/m). These results suggest that glycerol-liamocin is a potential novel biosurfactantfor use in various industrial applications.

Highlights

A surfactant molecule has both hydrophilic and hydrophobic moieties that can accumulate at interfaces, reduce surface and interfacial tensions, and form aggregate structures such as micelles, which consist of external hydrophilic moieties and internal hydrophobic moieties [1,2,3,4,5,6]
We isolated a yeast strain, L3-GPY, with potent surface activity from a tiger lily, Lilium lancifolium Thunb, which was screened among other yeast isolates from the homogenized flower samples by the drop-collapse test
The black yeast is the closest species to A. pullulans

Summary

Introduction

A surfactant molecule has both hydrophilic and hydrophobic moieties that can accumulate at interfaces, reduce surface and interfacial tensions, and form aggregate structures such as micelles, which consist of external hydrophilic moieties and internal hydrophobic moieties [1,2,3,4,5,6]. New Biosurfactant, Glycerol-Liamocin, Produced by A. pullulans The A. pullulans L3-GPY strain that we isolated exhibited potent biosurfactant activity. We describe the phylogenetic identification of this biosurfactant-producing yeast, isolation and structural determination of the active compound (glycerol-liamocin), and the biosurfactant activity.

Results

Conclusion