1. Department of Plant Sciences, Kenyatta University, P.O. Box 43844–00100, Nairobi, Kenya
2. Department of Biochemistry, University of Nairobi, P.O. Box 30197–00100, Nairobi, Kenya
3. Department of Biochemistry Microbiology and Biotechnology, Kenyatta University, P. O. Box 43844–00100, Nairobi, Kenya