The physicochemical properties and chemical composition of trehalose lipids produced by Rhodococcus erythropolis 51T7

• Published in: Chemistry and physics of lipids 2009-04, Vol.158 (2), p.110-117
• Main Authors: Marqués, A.M., Pinazo, A., Farfan, M., Aranda, F.J., Teruel, J.A., Ortiz, A., Manresa, A., Espuny, M.J.
• Format: Article
• Language: English
• Subjects: Animals; Biosurfactant; Cell Line; Cell Survival - drug effects; CMC/CAC; Emulsions - chemistry; Fibroblasts - cytology; Fibroblasts - drug effects; Genes, Bacterial; Genes, rRNA; Glycolipids - analysis; Glycolipids - isolation & purification; Glycolipids - toxicity; Humans; Hydrogen-Ion Concentration; Keratinocytes - cytology; Keratinocytes - drug effects; Liquid crystals; Mice; Micelles; Osmolar Concentration; Phase diagram; Phase Transition; Rhodococcus - chemistry; Rhodococcus - genetics; Rhodococcus erythropolis; Surface tension; Trehalose - analysis; Trehalose - isolation & purification; Trehalose - toxicity
• ISSN: 0009-3084; 1873-2941
• DOI: 10.1016/j.chemphyslip.2009.01.001

This study analyzed the chemical and physical properties of a biosurfactant synthesized by Rhodococcus sp. 51T7. The biosurfactant was a trehalose tetraester (THL) consisting of six components: one major and five minor. The hydrophobic moieties ranged in size from 9 to 11 carbons. The critical micelle concentration (CMC) was 0.037 g L −1 and the interfacial tension against hexadecane was 5 mN m −1. At pH 7.4 the glycolipid CMC/critical aggregation concentration (CAC) was 0.05 g L −1 and at pH 4 it was 0.034 g L −1. A phase diagram revealed effective emulsification with water and paraffin or isopropyl myristate. A composition of 11.3–7.5–81.8 (isopropyl myristate–THL–W) was stable for at least 3 months. The HLB was 11 and the phase behaviour of the glycolipid revealed the formation of lamellar and hexagonal liquid-crystalline textures.