1. Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria , Pretoria 0002 , South Africa
2. Department of Microbiology, University of Stellenbosch , Stellenbosch 7602 , South Africa
3. Institute for Microbial Biotechnology and Metagenomics, Department of Biotechnology, University of the Western Cape , Cape Town 7535 , South Africa
4. Department of Earth and Planetary Science, the University of Texas at Austin , Austin, TX 78712-1692 , United States
5. Department of Soil Science, University of Stellenbosch , Stellenbosch 7602 , South Africa
6. Department of Earth Sciences, Kent State University , Kent, OH 44240 , United States
7. Botany Department, Nelson Mandela University , Gqeberha 6019 , South Africa