1. Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
2. Department of Biochemistry, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
3. College of Agriculture and Environmental Science (CAES) Laboratories, University of South Africa, Private Bag X06, Johannesburg 0710, South Africa