Brevibacterium luteolum biosurfactant: Production and structural characterization

Biosurfactants (BS) are microbial-derived molecules showing surface activity and emulsification properties. These compounds are good candidates to replace synthetic surfactants for industrial applications however, commercial and industrial use of BS is limited due to low yields and the high cost associated to their production. This work reports the production of a new BS synthesized by a marine Brevibacterium luteolum, in order to perform its purification and structural characterization. Significant medium components for BS production were studied using a 23 factorial design in shake flask cultures. Production medium using 4% of carbon source, 2% of nitrogen source and 20% of artificial sea water generated a BS with a surface tension of 27 mN m−1. The BS was characterized as a mixture of lipopeptides containing fatty acid chains varying from 10 to 18 carbon units and 5% of total protein. Two proline-lipids with the fatty acid C16:0 and C18:0 respectively, and a lipopeptide with a fatty acid C16:0 linked to a peptide sequence Phe-Ala-X-X-Pro-Pro-Thr (X = Leu/Ile) were identified as the surface-active compounds produced by B. luteolum. Mineral oil was utilized as main carbon source for the lipopeptide production suggesting that the marine bacterium and its BS product can be useful in bioremediation or enhance oil recovery (EOR).