1. Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil
2. Department of Biology, City College and the Graduate Center, The City University of New York, Convent Avenue at 138 St., New York, NY 10031, USA
3. Embrapa Agrobiologia, Seropédica, Rio de Janeiro, Brazil
4. Departamento de Biologia, Universidade Federal de Roraima, Campus do Paricarana, Boa Vista, Brazil
5. Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada