1. a Department of Bioscience and Biotechnology , University of Strathclyde , Glasgow , G1 1XW , United Kingdom
2. b Department of Applied Chemistry and Microbiology , University of Helsinki , P.O. Box 56, FIN-00014 , Finland
3. c International Centre for Waste Technology (Africa), University of Natal , Private Bag X01, Scottsville , 3209 , South Africa
4. d Department of Microbiology and Biochemistry , University of the Orange Free State , P.O. Box 339, Bloemfontein , 9300 , South Africa
5. e Department of Bioscience and Biotechnology , University of Strathclyde , Glasgow , G1 1XW , United Kingdom