1. Department of Biology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada
2. Biological Sciences Division
3. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352
4. Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ-14220 Prague 4, Czech Republic
5. Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada