1. Department of Microbiology and Immunology, 1365–2350 Health Sciences Mall, University of British Columbia, Vancouver V6T 1Z3, Canada.
2. Department of Botany, 3529–6270 University Boulevard, University of British Columbia, Vancouver V6T 1Z4, Canada.
3. Department of Earth and Ocean Sciences, 6339 Stores Road, University of British Columbia, Vancouver V6T 1Z4, Canada.