Production and characterization of a trehalolipid biosurfactant produced by the novel marine bacterium Rhodococcus sp., strain PML026
Article first published online: 10 JUL 2013
© 2013 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 115, Issue 3, pages 744–755, September 2013
How to Cite
White, D.A., Hird, L.C. and Ali, S.T. (2013), Production and characterization of a trehalolipid biosurfactant produced by the novel marine bacterium Rhodococcus sp., strain PML026. Journal of Applied Microbiology, 115: 744–755. doi: 10.1111/jam.12287
- Issue published online: 14 AUG 2013
- Article first published online: 10 JUL 2013
- Accepted manuscript online: 24 JUN 2013 12:02AM EST
- Manuscript Accepted: 16 JUN 2013
- Manuscript Revised: 13 JUN 2013
- Manuscript Received: 17 APR 2013
- Rhodococcus ;
The aim of this study was to evaluate biosurfactant production by a novel marine Rhodococcus sp., strain PML026 and characterize the chemical nature and properties of the biosurfactant.
Methods and Results
A novel marine bacterium (Rhodococcus species; strain PML026) was shown to produce biosurfactant in the presence of hydrophobic substrate (sunflower oil). Biosurfactant production (identified as a trehalolipid) was monitored in whole-batch cultures (oil layer and aqueous phase), aqueous phase (no oil layer) and filtered (0·2 μm) aqueous phase (no oil or cells; extracellular) and was shown to be closely associated with growth/biomass production. Extracellular trehalolipid levels increased postonset of stationary growth phase. Purified trehalolipid was able to reduce the surface tension of water to 29 mN m−1 at Critical Micellar Concentration (CMC) of c. 250 mg l−1 and produced emulsions that were stable to a wide range of conditions (pH 2–10, temperatures of 20–100°C and NaCl concentrations of 5–25% w/v). Separate chemical analyses of the intact trehalolipid and its constituents demonstrated the compound was in fact a mixture of homologues (>1180 MW) consisting of a trehalose moiety esterified to a series of straight chain and hydroxylated fatty acids.
The trehalolipid biosurfactant produced by the novel marine strain Rhodococcus sp. PML026 was characterized and exhibited high surfactant activity under a wide range of conditions.
Significance and Impact of Study
Strain PML026 of Rhodococcus sp. is a potential candidate for bioremediation or biosurfactant production for various applications.