Over the past decade great progress has been made in characterizing the abundance and diversity of the deep subsurface biosphere, but many mysteries remain to be answered when it comes to the in situ processes of growth, biogeochemical cycling, evolution and death of subsurface microorganisms. The workshop, New Horizons for International Investigations into Carbon Cycling in the Deep Crustal Biosphere, brought together scientists from Canada, Germany, Belgium, Switzerland, Sweden, Finland, Russia, the United States and South Africa to explore new approaches for retrieving geochemical, isotopic, metagenomic, transcriptomic, metabolomic, and proteomic information from the deep subsurface biosphere.

Topics covered ranged from the interactions between subsurface microorganisms and their environment, to protein structures from subsurface thermophiles, to bioremediation of toxic metals, to carbon dioxide sequestration, to lipid biochemistry, to the use of RNA to document subsurface activity. The workshop also inaugurated the Network of Inner Space Observatories (NISO), an international research network dedicated to the development of underground laboratories and mines for microbial studies.

The setting, University of the Free State, Bloemfontein, South Africa, was appropriate given the discovery of abiogenic hydrocarbons and radiolytic hydrogen in the deep fractures of the Witwatersrand Basin, the recent publication of the first subsurface metagenome from 2.8 km depth at Mponeng Au mine, and the recent establishment of an underground laboratory at 3.8 km depth in Tau Tona Au mine for microbial studies.

This workshop is sponsored by the Deep Carbon Observatory and hosted by the Department of Microbial, Biochemical and Food Biotechnology, University of the Free State.