Compositional Characterization of Biosurfactant Produced from Pseudomonas aeruginosa ENO14-MH271625 and its Application in Crude Oil Bioremediation
Objectives: This study aimed to compositionally characterize the biosurfactant and its application in crude oil bioremediation. Methods: Production of biosurfactant was carried out in Bushnell Hass Broth (BHB), supplemented with 1% glucose. Compositional characterizations were performed by 1H-NMR and ESI-MS analysis. The biodegradation of crude oil was carried out by using a 0.1% (g/v) of purified biosurfactant (ENO14BS). The experiment has three sets namely Set A, Set B and Set C. The experiments are as follows: Set A contained 50 ml sterilized BHB medium with bacterial cells (5% v/v, O.D.600 ~ 1.0), 2% (v/v) of crude oil and ENO14BS (0.1 % w/v). Set B contained 50 ml of sterilized BHB medium with bacterial cells (5% v/v, O.D.600 nm ~ 1.0) and 2% (v/v) of crude oil. Set C (abiotic control) contained 50 ml of sterilized BHB with 2% (v/v) of crude oil only. This experiment was performed for 7 days. Results: Structural elucidation by NMR and Electrospray Ionization-Mass Spectroscopy (ESIMS) showed the presence of six uncommon rhamnolipid homologs, m/z (mass to charge ratio) = 358.98 [M+H]+, Rha-C12:2; m/z = 391.28 [M+H]+, Rha–C6–C6; m/z = 427.38 [M+H]+, Rha–C17:3; m/z = 447.32 [M+H]+, Rha–C8- C8; m/z = 507.22 [M+H]+, Rha-Rha-C12:1; m/z = 648.17 [M+H]+, Rha-Rha- C10-C10:1. The application of biosurfactant (ENO14BS) in biodegradation of crude oil was performed at a laboratory scale. The biosurfactant (0.1% w/v) amended microcosm showed up to 73% crude oil degradation (31% higher than with culture alone) in four days. Conclusion: We conclude that ENO14BS biosurfactant produced by Pseudomonas aeruginosa ENO14 using glucose in this study has shown its potential for use in the crude oil bioremediation process.