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. 2023 Nov 15;11(11):2772.
doi: 10.3390/microorganisms11112772.

Microbial Biosurfactant: Candida bombicola as a Potential Remediator of Environments Contaminated by Heavy Metals

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Microbial Biosurfactant: Candida bombicola as a Potential Remediator of Environments Contaminated by Heavy Metals

Renata Raianny da Silva et al. Microorganisms. .

Abstract

Industrial interest in surfactants of microbial origin has intensified recently due to the characteristics of these compounds, such as biodegradability and reduced toxicity, and their efficiency in removing heavy metals and hydrophobic organic compounds from soils and waters. The aim of this study was to produce a biosurfactant using Candida bombicola URM 3712 in a low-cost medium containing 5.0% molasses, 3.0% corn steep liquor and 2.5% residual frying oil for 144 h at 200 rmp. Measurements of engine oil tension and emulsification were made under extreme conditions of temperature (0 °C, 5 °C, 70 °C, 100 °C and 120 °C), pH (2-12) and NaCl concentrations (2-12), demonstrating the stability of the biosurfactant. The isolated biosurfactant was characterized as an anionic molecule with the ability to reduce the surface tension of water from 72 to 29 mN/m, with a critical micellar concentration of 0.5%. The biosurfactant had no toxic effect on vegetable seeds or on Eisenia fetida as a bioindicator. Applications in the removal of heavy metals from contaminated soils under dynamic conditions demonstrated the potential of the crude and isolated biosurfactant in the removal of Fe, Zn and Pb with percentages between 70 and 88%, with the highest removal of Pb being 48%. The highest percentage of removal was obtained using the cell-free metabolic liquid, which was able to remove 48, 71 and 88% of lead, zinc and iron from the soil, respectively. Tests in packed columns also confirmed the biosurfactant's ability to remove Fe, Zn and Pb between 40 and 65%. The removal kinetics demonstrated an increasing percentage, reaching removal of 50, 70 and 85% for Pb, Zn and Fe, respectively, reaching a greater removal efficiency at the end of 24 h. The biosurfactant was also able to significantly reduce the electrical conductivity of solutions containing heavy metals. The biosurfactant produced by Candida bombicola has potential as an adjuvant in industrial processes for remediating soils and effluents polluted by inorganic contaminants.

Keywords: Candida bombicola; bioremediation; biosurfactant; heavy metals.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
FTIR spectrum of the isolated biosurfactant produced by C. bombicola in distilled water supplemented with 5.0% molasses, 3.0% corn steep liquor and 2.5% residual frying oil.
Figure 2
Figure 2
1H MNR spectrum (CD3OD, 300 MHz) of the isolated biosurfactant of C. bombicola in distilled water supplemented with 5.0% molasses, 3.0% corn steep liquor and 2.5% residual frying oil.
Figure 3
Figure 3
C MNR spectrum of the biosurfactant produced by C. bombicola in distilled water supplemented with 5.0% molasses, 3.0% corn steep liquor and 2.5% residual frying oil.
Figure 4
Figure 4
Ecotoxicological test using Eisenia fetida as test organism. (A) Earthworms separated into Petri dishes; (B) control soil and soil with solutions tested separated by a plastic divider; (C) plastic divider removed and the worms were placed in the center of the box; (D) boxes covered to prevent the worms from escaping.
Figure 5
Figure 5
Removal of heavy metals by cell-free C. bombicola over time.

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References

    1. Gaur V.K., Regar R.K., Dhiman N., Gautam K., Srivastava J.K., Patnaik S., Kamthan M., Manickam N. Biosynthesis and characterization of sophorolipid biosurfactant by Candida spp.: Application as food emulsifier and antibacterial agent. Bioresour. Technol. 2019;285:121314. doi: 10.1016/j.biortech.2019.121314. - DOI - PubMed
    1. Almeida D.G., Soares da Silva R.D.C.F., Meira H.M., Brasileiro P.P.F., Silva E.J., Luna J.M., Rufino R.D., Sarubbo L.A. Production, characterization and commercial formulation of a biosurfactant from Candida tropicalis UCP0996 and its application in decontamination of petroleum pollutants. Processes. 2021;9:885. doi: 10.3390/pr9050885. - DOI
    1. Santos E.M.S., Lira I.R.A.S., Meira H.M., Aguiar J.S., Rufino R.D., Almeida D.G., Casazza A.A., Converti A., Sarubbo L.A., Luna J.M. Enhanced oil removal by a non-toxic biosurfactant formulation. Energies. 2021;14:467. doi: 10.3390/en14020467. - DOI
    1. Akbari S., Abdurahman N.H., Yunus R.M., Fayaz F., Alara O.R. Biosurfactants—A new frontier for social and environmental safety: A mini review. Biotechnol. Res. Innov. 2018;2:81–90. doi: 10.1016/j.biori.2018.09.001. - DOI
    1. Dhaliwal S.S., Singh J., Taneja P.K., Mandal A. Remediation techniques for removal of heavy metals from the soil contaminated through different sources: A review. Environ. Sci. Pollut. Res. 2020;27:1319–1333. doi: 10.1007/s11356-019-06967-1. - DOI - PubMed

Grants and funding

This research was funded by the following agencies: Science and Technology Assistance Foundation of the state of Pernambuco (Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco—FACEPE), National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq) and Higher Education Personnel Improvement Coordination (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—CAPES, Finance Code 001).

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