1. Department of Microbiology and Parasitology, Institute of Biology, Federal University of Pelotas , CEP 96010-900 Pelotas, RS , Brazil
2. Department of Microbiology, State University of Londrina , CEP 86057-970 Londrina, PR , Brazil
3. Biotechnology Nucleus, Technological Development Center, Federal University of Pelotas , CEP 96010-900 Pelotas, RS , Brazil