Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2019

Bacteria living on thin air - strategies for survival in the harsh Antarctic environment (#190)

Belinda Ferrari 1
  1. UNSW Sydney, RANDWICK, NSW, Australia

Antarctica is the coldest, driest and windiest continent on the planet. Yet the desert soils of east Antarctica host a great diversity of microbial communities that have evolved unique strategies to survive under the extremely harsh conditions. Microbes dominant terrestrial Antarctica and in doing so must endure frequent freeze-thaw cycles, complete winter darkness, limited nutrient and water availability and intense UV radiation. We have found that in the dry desert surface soils of the Windmill Islands and Vestfold Hills regions, very few phototrophs such as cyanobacteria or algae exist. Instead, novel bacterial phyla with new functional capacities are thriving under the stressful conditions.  By combining metagenomics with differential coverage binning and functional assays we proposed that trace gas chemosynthesis, a new form of primary production was supporting microbial communities living in these nutrient poor environments. This aerobic energy-capture process relies on the oxidation of atmospheric levels of hydrogen and carbon monoxide gas to provide the fuel required to fix COvia the Calvin-Benson-Bassham cycle, and provides new understanding of the nutritional limits for life. Today I will focus on the significance of this alternative form of primary production, while providing new information on the physiology and environmental drivers of Candidatus Eremiobacteraeota (WPS-2) and Candidatus Dormibactereaota (AD3), two yet to be cultured bacterial phyla whose members have the genetic capacity to live on thin air.