Abstract

  The objective assigned to this study is the optimization of azote nutriment source for the microbial bioremediation to contribute to the fight against environmental pollution through the production of biosurfactants of multidisciplinary interest. This study consists in metabolizing hydrocarbons into biosurfactants using Pseudomonas aeruginosa ATCC 27853 strain in order to control the environmental threat in a batch of 250 ml at 37°C for 48 hours of culture. The optimization tests of nitrogen source showed that within a range of concentration [1 - 8] g/l, the optimum value was 4 g/l for KNO₃ with an emulsification index EI₂₄ = 71.45% and an optical density DO_X = 0.55 for 46h of culture. The yields obtained Y_x/s and Y_p/s were of 60.00% and 32.17% respectively with an amount of biosurfactants P = 580 mg, a bioconversion rate θ = 78.47% and a ratio N/C = 0.473. The comparative study between two nitrogen sources such as KNO₃ and NH₄NO₃ for a range of concentration [3 - 4] g/l demonstrated that the best source of nitrogen remains KNO₃. Indeed, the kinetic monitoring of the biomass growth, the emulsification index, the biosurfactants productivity and the substrates consumption revealed the inhibition of the strain by NH₄NO₃ after 7 hours of incubation, provoking the degeneration of the strain and slowing the removal of pollutants process. A similar study of NH₄NO₃ at a concentration of 4 g/l resulted in an emulsification index EI₂₄ = 65.22%, a yields Y_x/s = 18.37% and Y_p/s = 45.17% and a bioconversion rate θ = 57.36%. The amount of the biosurfactants measured at P = 590 mg for an N/C ratio of 0.739. In fact, the results of this study demonstrated that KNO₃ promotes the growth of biomass as well as the production of biosurfactants who play a major role in the enrichment of the soil by solubilizing the toxic elements and a maximum removal of hydrocarbons following diauxic phenomena.

Keywords: Pollution; Environment; Bioremediation; Biosurfactants; Optimization

References

1. Winquist E., et al. “Bioremediation of PAH-contaminated soil with fungi-From laboratory to field scale”. International Biodeterioration and Biodegradation 86 (2014): 238-247.
2. Janbandhu A and Fulekar MH. “Biodegradation of phenanthrene using adapted microbial consortium isolated from petrochemical contaminated environment”. Journal of Hazardous Materials 1-3 (2011): 333-340.
3. Haderlein A., et al. “Pyrene mineralization capacity increases with compost maturity”. Biodegradation 4 (2006): 293-302.
4. Tyagi M., et al. “Bioaugmentation and biostimulation strategies to improve the effectiveness of bioremediation processes”. Biodegradation2 (2011): 231-241.
5. Taccari M., et al. “Effects of biostimulation and bioaugmentation on diesel removal and bacterial community”. International Biodeterioration Biodegradation1 (2012): 39-46.
6. AL-Saleh E and Akbar A. “Occurrence of Pseudomonas aeruginosa in Kuwait soil”. Chemosphere 120 (2015): 100-107.
7. Milena GR., et al. “Production and characterization of rhamnolipids from Pseudomonas aeruginosa san-ai”. Journal of the Serbian Chemical Society 77 (2012): 27-42.
8. Graziela JP., et al. “Production of Biosurfactants by Rhodococcus erythropolis and their application for enhance to remove oil”. Brazilian Journal of Microbiology3 (2010): 1-7.
9. Atipan S., et al. “Biosurfactant production by Bacillus subtilis TD4 and Pseudomonas aeruginosa SU7 grown on crude glycerol obtained from biodiesel production plant as sole carbon source”. Journal of Scientific and Industrial Research6 (2012): 396-406.
10. Kumar AP., et al. “Evaluation of orange peel for biosurfactant production by Bacillus licheniformis and their ability to degrade naphthalene and crude oil”. 3 Biotech1 (2016): 43.
11. Raquel DR., et al. “Characterization and properties of the biosurfactant produced by Candida lipolytica UCP 0988”. Electronic Journal of Biotechnology1 (2014): 34-38.
12. Samira F., et al. “Production and characterization of biosurfactant by free and immobilized cells from Ochrobactrum intermedium isolated from the soil of southern Algeria with a view to environmental application”. Biotechnology and Biotechnological Equipment4 (2017): 733-742.
13. Das K and Mukherjee AK. “Crude petroleum-oil biodegradation efficiency of Bacillus subtilis and Pseudomonas aeruginosa strains isolated from a petroleum-oil contaminated soil from North-East India”. Bioresource Technology7 (2007): 1339-1345.
14. El-Sheshtawy HS and Doheim MM. “Selection of Pseudomonas aeruginosa for biosurfactant production and studies of its antimicrobial activity”. Egyptian Journal of Petroleum1 (2014): 1-6.
15. Musa NM., et al. “Bioremediation of Petroleum Refinery Wastewater Effluent via Augmented Native Microbes”. Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 6 (2015): 1-6.
16. Souza EC., et al. “Biosurfactant-enhanced hydrocarbon bioremediation: An overview”. International Biodeterioration and Biodegradation 89 (2014): 88-94.
17. Cerqueira VS., et al. “Comparison of bioremediation strategies for soil impacted with petrochemical oily sludge”. International Biodeterioration and Biodegradation 95 (2014): 338-345.
18. Brzeszcz J., et al. “r-strategist versus K-strategist for the application in bioremediation of hydrocarbon-contaminated soils”. International Biodeterioration and Biodegradation 106 (2016): 41-52.
19. Górna H., et al. “Differences and dynamic changes in the cell surface properties of three Pseudomonas aeruginosa strains isolated from petroleum-polluted soil as a response to various carbon sources and the external addition of rhamnolipids”. Bioresource Technology3 (2011): 3028-3033.
20. Reis RS., et al. “Gene regulation of rhamnolipid production in Pseudomonas aeruginosa-A review”. Bioresource Technology11 (2011): 6377-6384.
21. Yan P., et al. “Oil recovery from refinery oily sludge using a rhamnolipid biosurfactant-producing Pseudomonas”. Bioresource Technology 116 (2012): 24-28.
22. Das P and Ma LZ. “Pyocyanin pigment assisting biosurfactant-mediated hydrocarbon emulsification”. International Biodeterioration and Biodegradation 85 (2013): 278-283.
23. Rocha e Silva NMP., et al. “Screening of Pseudomonas species for biosurfactant production using low-cost substrates”. Biocatalysis and Agricultural Biotechnology2 (2014): 32-139.
24. Brown DM., et al. “Comparison of landfarming amendments to improve bioremediation of petroleum hydrocarbons in Niger Delta soils”. Science of the Total Environment 596-597 (2017): 284-292.
25. Koshlaf E and Ball AS. “Soil bioremediation approaches for petroleum hydrocarbon polluted environments”. AIMS Microbiology 3 (2017): 25-49.
26. Pacwa-Płociniczak M., et al. “Environmental Applications of Biosurfactants: Recent Advances”. International Journal of Molecular Sciences 12 (2011): 633-654.
27. Kildisas V., et al. “Development of clean-up complex technology of soil contaminated by oil pollutants based on cleaner production concepts”. Environmental Resource Engineering Management 25 (2003): 87-93.

Citation

Citation: Bassirou Mahamadou Harouna and Othmane Benkortbi. “Optimization of Diauxienne Growth of Pseudomonas aeruginosa in the Bioremediation of Soils Polluted by Hydrocarbons". Acta Scientific Microbiology 3.4 (2020): 233-238.

Copyright

Copyright: © 2020 Bassirou Mahamadou Harouna and Othmane Benkortbi. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.