Rhamnolipid-producing thermophilic bacteria of species Thermus and Meiothermus
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Novel rhamnolipid-producing strains of three thermophilic bacteria, Thermus sp., T. aquaticus and Meiothermus ruber were identified that have not been previously described as rhamnolipid producers. Rhamnolipids were extracted from supernatant and further purified by thin-layer chromatography. Mass spectrometry with negative electrospray ionization revealed 77 rhamnolipid homologues varying in chain length and unsaturation. Tandem mass spectrometry identified mono-rhamnolipid and di-rhamnolipid homologues containing one or two 3-hydroxy-fatty acids, saturated, monounsaturated or diunsaturated, even- or odd-chain, up to unusual long chains with 24 carbon atoms. The stereochemistry of rhamnose was L and that of 3-hydroxy-fatty acids was R, the position of double bonds in monoenoic acids was cis ω-9. All three strains produced a rhamnolipid that differs in structure from Pseudomonas aeruginosa rhamnolipids and exhibits excellent surfactant properties. Importantly, in comparison to P. aeruginosa both strains, i.e., Thermus and Meiothermus, are Biosafety level 1 microorganisms and are not pathogenic to humans.
KeywordsThermus sp. T. aquaticus Meiothermus ruber Rhamnolipids Tandem mass spectrometry Biosurfactant
The research was supported by GACR P503/10/P182, GACR P503/11/0215, and by Institutional Research Concept AV 0Z 502 0910.
- Bus J, Sies I, Lie Ken Jie MSF. 13C NMR of methyl, methylene and carbonyl carbon atoms of methyl alkenoates and alkynoates. Chem Phys Lipids. 1976;17:501–18.Google Scholar
- Christie WW, Han X. Lipid analysis. 4th ed. Bridgwater: Oily Press; 2010.Google Scholar
- Deziel E, Lepine F, Milot S, Villemur R. Mass spectrometry monitoring of rhamnolipids from a growing culture of Pseudomonas aeruginosa strain 57RP. Biochim Biophys Acta/Mol Cell Biol Lipids. 2000;1485:145–52.Google Scholar
- Horikoshi K, editor. Extremophiles Handbook. Tokyo: Springer; 2011.Google Scholar
- Shen W, Yang S, Li X. Electrospray ionization mass spectrometric detection of rhamnolipids and their acid precursors in Pseudomonas sp. BS-03 cultures. Chin J Biotechnol. 2005;25:83–7.Google Scholar
- Soberon-Chavez G, editor. Biosurfactants, from genes to applications, vol. 20 A. Berlin: Springer; 2011.Google Scholar