Compositional Characterization of Biosurfactant Produced from Pseudomonas aeruginosa ENO14-MH271625 and its Application i n 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 H-1-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) similar to 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)similar to 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 (ESI-MS) showed the presence of six uncommon rhamnolipid homologs, m/z (mass to charge ratio) = 358.98 [M+H](+), Rha-C-12:2; m/z = 391.28 [M+H](+), Rha-C6-C6; m/z = 427.38 [M+H](+), Rha-C-17:3; m/z = 447.32 [M+H](+), Rha-C8- C8; m/z = 507.22 [M+H](+), Rha-Rha-C-12:1; 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.

Automated summary

The study characterized the composition of biosurfactant using H-1-NMR and ESI-MS analysis, and demonstrated successful crude oil biodegradation using purified biosurfactant. The results showed promising potential for the application of biosurfactant in crude oil bioremediation.