1. Discipline of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
2. Department of Biological Sciences, Summit University, Offa 250101, Nigeria
3. Centre for Mineral Biogeochemistry, University of the Free State, Bloemfontein 9031, South Africa