Inhibitory Effects of Ternary Mixtures of Sodium Dodecyl Sulfate and Heavy Metals to Acinetobacter seifertii from Otamiri River Sediment in Southeastern Nigeria

Authors

  • Reuben Nwoye Okechi Department of Biotechnology, Federal University of Technology Owerri, Owerri, Imo State, Nigeria
  • Edna Ifeoma Chukwura Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria
  • Christain Okechukwu Nweke Department of Microbiology, Federal University of Technology Owerri, Owerri, Imo State, Nigeria

DOI:

https://doi.org/10.5132/eec.2021.01.01

Abstract

Toxicities of sodium dodecyl sulfate (SDS) and heavy metals, Pb(II), Cd(II), Ni(II), Zn(II) and Co(II), as individuals and ternary mixtures of two heavy metals and SDS to Acinetobacter seifertii isolated as preponderant bacterium from Otamiri river sediment, were assessed, using inhibition of dehydrogenase activity as end point. Among the individual toxicants, the EC50S observed ranged from 0.011 ± 0.000 mM for Cd(II) to 2.810 ± 0.140 mM for SDS. The EC50S of the toxicants were statistically different from one another and the order of increasing toxicities were SDS > Ni(II) > Pb(II) > Zn(II) > Co(II) >Cd(II). The responses of the bacterium were concentration -dependent. Arbitrary (ABCR) and EC50 equieffect (EECR) fixed ratio mixtures were used to evaluate the combined toxicities of the toxicants. The concentration-response relationships of all mixtures and individual toxicants were sigmoidal and fitted with logistic function. The observed toxicities (EC50S) were compared with toxicities predicted from concentration addition (CA) and independent action (IA) models. In ABCR1 and ABCR3 mixture ratios of SDS+Ni(II)+Cd(II) and SDS+Co(II)+Cd(II) ternary mixtures, both CA- and IA-predicted EC50S were not statistically different from each other. Furthermore, in all ternary mixtures, both models underestimated the mixture toxicities to A. seifertii, except in ABCR1 of SDS+Ni(II)+Cd(II) mixture, where both models almost correctly predicted the toxicities. Basically, synergistic interaction of the mixture components observed against A. seifertii, indicates their possible toxicological effects on the bacterial population of the aquatic ecosystems.

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Author Biographies

Reuben Nwoye Okechi, Department of Biotechnology, Federal University of Technology Owerri, Owerri, Imo State, Nigeria

DEPARTMENT OF BIOTECHNOLOGY, LECTURER 1

Edna Ifeoma Chukwura, Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria

DEPARTMENT OF APPLIED MICROBIOLOGY AND BREWING, PROF

Christain Okechukwu Nweke, Department of Microbiology, Federal University of Technology Owerri, Owerri, Imo State, Nigeria

DEPARTMENT OF MICROBIOLOGY, PROF

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Published

03-10-2021

How to Cite

Okechi, R. N., Chukwura, E. I., & Nweke, C. O. (2021). Inhibitory Effects of Ternary Mixtures of Sodium Dodecyl Sulfate and Heavy Metals to Acinetobacter seifertii from Otamiri River Sediment in Southeastern Nigeria. Ecotoxicology and Environmental Contamination, 16(1), 1–11. https://doi.org/10.5132/eec.2021.01.01

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Original Articles