International Science Community Association International Research Journal of Biological Sciences 2278-3202 9 2 2020 05 10 Toxicities of senary and septenary mixtures of five metals and two phenols to Pseudomonas fluorescens 19 31 EN Oludare Agbolade James 1 Department of Plant Science and Biotechnology, Federal University Oye Ekiti, Ekiti State, Nigeria Mary Popoola Kehinde 2 Department of Plant Science and Biotechnology, Federal University Oye Ekiti, Ekiti State, Nigeria Adebare Ganiyu Sikiru 3 Department of Agronomy, Federal University, Keshere, Gombe State, Nigeria Philip Olakunle Teju 4 Department of Applied Sciences, Osun State Polytechnic, Iree Rasheed Popoola Akinola 5 Department of Crop Protection, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria Sunday OJO Elijah 6 Department of Crop Protection, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria Ehis Imonmion Joshua 7 Department of Crop Protection, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria Perfusion Amang A. 1 Department of Biological Sciences, Faculty of Science, University of Maroua, P.O. Box 814, Maroua, Cameroon Luc Vandi V. 2 Department of Biological Sciences, Faculty of Science, University of Maroua, P.O. Box 814, Maroua, Cameroon Christophe Mezui 3 Department of Biological Sciences, Higher Teachers' Training College, University of Yaoundé I, P.O. Box 47, Yaoundé, Cameroon Gael Siwe T. 4 Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon Mesmine Kuissu T. 5 Institute of Medical Research and Study of Medicinal Plants, P.O. Box 13033 Yaoundé, Cameroon Vernyuy Tan P. 6 Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon Perfusion Amang A. 1 Department of Biological Sciences, Faculty of Science, University of Maroua, P.O. Box 814, Maroua, Cameroon Luc Vandi V. 2 Department of Biological Sciences, Faculty of Science, University of Maroua, P.O. Box 814, Maroua, Cameroon Christophe Mezui 3 Department of Biological Sciences, Higher Teachers' Training College, University of Yaoundé I, P.O. Box 47, Yaoundé, Cameroon Gael Siwe T. 4 Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon Mesmine Kuissu T. 5 Institute of Medical Research and Study of Medicinal Plants, P.O. Box 13033 Yaoundé, Cameroon Vernyuy Tan P. 6 Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon Maroua Leguemairi 1 Department of Cellular and Molecular Biology, Faculty of Natural Sciences and Life, El Oued University, El Oued 39000, El Oued, Algeria Saadia Salem 2 Department of Cellular and Molecular Biology, Faculty of Natural Sciences and Life, El Oued University, El Oued 39000, El Oued, Algeria Samir Derouiche 3 Department of Cellular and Molecular Biology, Faculty of Natural Sciences and Life, El Oued University, El Oued 39000, El Oued, Algeria Nweke Christian O. 1 Department of Microbiology, Federal University of Technology Owerri, P.M.B 1526 Owerri, Nigeria Nwachukwu Ikenna N. 2 Department of Microbiology, Federal University of Technology Owerri, P.M.B 1526 Owerri, Nigeria Opurum Christian C. 3 Department of Microbiology, Federal University of Technology Owerri, P.M.B 1526 Owerri, Nigeria Aguh Maureen N. 4 Department of Microbiology, Federal University of Technology Owerri, P.M.B 1526 Owerri, Nigeria > Research Paper 2019 12 28 2020 05 10 Toxicities of senary (Ni(II) + Co(II) + Zn(II) + Cd(II) + Pb(II) + 2-Chlorophenol and Ni(II) + Co(II) + Zn(II) + Cd(II) + Pb(II) + Phenol) and septenary (Ni(II) + Co(II) + Zn(II) + Cd(II) + Pb(II) + Phenol + 2-Chlorophenol) mixtures of five metals and two phenols to Pseudomonas fluorescens were assessed through dehydrogenase inhibition. Fixed ratio mixtures comprising equieffect concentration ratio (EECR) mixtures and arbitrarily chosen mixture ratios (ABCR) were used to determine the joint effects of these heavy metals in mixture with either 2-chlorophenol or phenol or both. The concentration-response relationships of all the toxicants and their mixtures were describable by logistic model. Generally, concentration addition (CA) predicted higher toxicities than independent action (IA) models. The mixture toxicities were generally synergistic. This is of environmental concern and underlines the hazard in discharging effluents containing phenols and heavy metals. Copyright@ International Science Community Association