Production of new rhamnolipids Rha C16-C16 by Burkholderia sp. through biodegradation of diesel and biodiesel

Abstract

Burkholderia sp. C3 was previously isolated from polycyclic aromatic hydrocarbons (PAH) contaminated soil; it was evaluated for the ability to utilize a range of diesel and biodiesel as sole carbon sources. Burkholderia sp. C3 could degrade 99% of diesel and biodiesel supplemented at 2% (v/v) in a basal mineral medium within 3 days of incubation at 30 °C. The produced rhamnolipids (RL), from diesel degrading bacteria, were characterized by Orcinol test and Mass spectrometry (MS). The MS confirmed that RLs structure compounds had a mixture of mono-rhamno-mono-lipidic, mono-rhamno-di-lipidic and di-rhamno-di-lipidic congeners. Burkholderia sp. produced a mixture of rhamnolipid homologues, as identified by mass spectrometry, while the composition of rhamnolipids depended upon the carbon substrates. The homologues rhamnolipid Rha-Rha-C10-C10, Rha-C10-C10 and Rha-Rha-C12-C12 were the predominant structures. Rha-C12-C14, Rha-C10-C12, Rha-Rha-C10-C12, and Rha-Rha-C12-C14 were detected as minor components. The efficient employment of Burkholderia sp., for the bioremediation of diesel contamination and production of RLs from it, could be recommended from this study. Keywords: Bioremediation, Biosurfactant, Mass analysis, Oil Spills