1. Department of Plant Science and Biotechnology, Michael Okpara University of Agriculture, Umudike, Nigeria
2. Department of Biochemistry, Michael Okpara University of Agriculture, Umudike, Nigeria
3. Department of Nature Conservation and Ethnobotany, Mangosuthu University of Technology, P.O. Box 12363, Jacobs, Durban 4026, South Africa
4. GI Microbiology and Biotechnology Unit, Agricultural Research Council, Animal Production Institute, Irene, Pretoria 0062, South Africa