Genomic survey of microbial ‘dark matter’ sheds light on BC’s unseen biodiversity

A landmark single-cell genomic study of microorgansims from sites across the globe is underscoring British Columbia's role as an 'oasis' of biodiversity. The findings, to be published Sunday in Nature, could also prompt scientists to redefine how the tree of life represents relationships among and between life’s three domains.

"British Columbia has long been recognized for its biological diversity in flora and fauna," says University of British Columbia microbiologist Steven Hallam, Canada Research Chair in Environmental Genomics and one of the study’s authors. “What we’re discovering now is that our province is also an oasis for the vital biological diversity we can’t see—diversity encoded in the genomes of uncultivated, or wild, microorganisms.”

Representatives from about a third of the uncultivated microbial groups described by the survey were culled from samples taken from British Columbia’s pristine Sakinaw Lake, situated on the Sunshine Coast. It’s one of nine sites around the world targeted in the survey by an international team of researchers.

"The study remaps our understanding of life’s unseen majority, and going forward should help us to better recognize and interpret microbial community interactions that drive essential ecosystem functions and services in the world around us."

Study in brief

• The study’s single-cell genome data provide 11% greater coverage of known genetic diversity than currently available genome libraries.
• The study could require the reorganization of the Archaea domain, which categorizes single cell organisms. The authors are proposing two new superphyla and four new phyla within the Archaea domain.

The Nature paper details the collection and single-cell sequencing of 200 archaeal bacteria cells in 29 major uncharted branches of the tree of life from nine diverse habitats across the globe. Samples and data from hydrothermal vets, fresh and seawater, soil and other habitats were used from sites in Africa, Europe, and the Americas.

The team of 22 researchers from 11 institutions around the world was led by the US Department of Energy’s Joint Genome Institute in California. Hallam’s research is supported by the Natural Sciences and Engineering Research Council of Canada, the Tula Foundation and the Canadian Institute for Advanced Research.