Soil bacteria that can oxidise atmospheric trace gases (H2, CO, and to a lesser extent CH4) are the majority, not the minority. In our new study, led by Sean Bay, Eleonora Chiri and Chris Greening of Monash University, we profile the metabolism of soil microbial communities using genome-resolved metagenomics, in situ and ex situ biogeochemistry, and thermodynamic modelling. We find that trace gas oxidizers are widespread and active members of soil microbial communities. Bacteria than can oxidise these gases span at least 19 phyla, and rapidly consume atmospheric hydrogen and carbon monoxide to supply energy - conferring a major selective advantage in soil ecosystems where availability of soil organic matter is a major limit to growth. This finding has broad implications for understanding atmospheric chemistry and microbial biodiversity in a changing world. You can read the paper here:
Bay S, Dong X, Bradley J, Leung P M, Grinter R, Jirapanjawat T, Arndt S, Cook P, LaRowe D, Nauer P, Chiri E, Greening C. (2021) Trace gas oxidizers are widespread and active members of soil microbial communities. Nature Microbiology. doi: 10.1038/s41564-020-00811-w
James is currently doing fieldwork in the High-Arctic archipelago of Svalbard (79°N). It’s the middle of winter and polar night, which means 24-hour darkness and temperatures well-below freezing.
Field studies on snow and ice phenomena are often restricted to a single season – usually the spring or summer period. Therefore, the understanding of Arctic climate, biogeochemistry, and ecosystems during the winter and on a seasonal basis is limited by a lack of observations.
We are sampling the Arctic snowpack overlying glaciers and tundra, as well as drilling cores of glacier ice, to better-understand the year-round microbial and biogeochemical dynamics of these high-latitude systems.
Working during the polar night presents unique challenges such as navigation and route-finding across ever-changing fields of crevasses, polar bear watch in the darkness, highly changeable weather conditions (typically high winds and temperatures well below freezing), and the practicalities of sampling frozen soils which are buried underneath thick snow-packs and near-impenetrable layers of refrozen ice.
Yet, the rewards are plentiful: truly novel data and insight into the functioning of glacier and glacier-adjacent systems during the long polar night, ski expeditions in the darkness, stunning auroras, and cosy activities with the overwintering community in the northernmost settlement in the world.
Photo credit (left to right): James Bradley, Dagmara Wojtanowicz, James Bradley
Congratulations to Bradley Lab PhD student Margaret Cramm, who co-authors a new paper in Science, investigating the temperature limit to deep biosphere life. Click through to read the paper here.
Congratulations to Bradley Lab PhD student Margaret Cramm, who has published two exciting new research articles:
First, Margaret is lead-author on a study that characterizes marine microbial communities around an Arctic seabed hydrocarbon seep at Scott Inlet, Baffin Bay. Margaret and co-authors found bacteria typically associated with hydrocarbon and methane oxidation - highlighting the potential role of microbes in mitigating a significant portion of hydrocarbon emissions from the Arctic seep. The study is publishes in Science of the Total Environment, and you can read it here.
Second, Margaret co-authors an exciting new study on subseafloor thermophilic endospores and their response to cooling. The study, published in Environmental Microbiology, is led by Emma Bell of the University of Calgary. Read the paper by following this link.
I am recruiting a 3-year post-doc in Arctic soil biogeochemical modelling. This post is part of an exciting new collaborative project with CU Boulder, U Utah, Montana Tech & British Geological Survey, investigating the fate of Arctic soil following glacier retreat. The post-doc will develop a novel microbial-biogeochemical model for Arctic soils, to better understand how seasonal processes contribute to the long-term development of Arctic soils. The model will link soil biogeochemical, microbial, geophysical and hydrogeological processes. Opportunities to participate in fieldwork in Svalbard.
Apply via the link below before 15th January 2021 for full consideration.
New article published in EOS discussing how to nurture diversity in the geosciences, and support early career researchers during the pandemic
In this EOS article, we discuss how the coronavirus pandemic has exacerbated long-standing issues with diversity of the geosciences, and the various negative impacts on early career researchers.
We draw from our own experiences to reflect on how the pandemic is exacerbating systemic issues faced by early-career scientists in the Earth sciences. We offer recommendations to address three challenges: job opportunities, support for early-career scientists, and diversity.
"The current upheaval is an opportunity to implement changes that can create more inclusive and diverse academic environments while also supporting the needs of early-career scientists."
Our recommendations are intended to assist all early-career scientists, but we hope they will particularly help those from underrepresented groups. Moreover, we hope that this period marks the beginning of a new era of inclusion and diversity in the Earth sciences.
Read the paper here.
I am delighted to welcome three new PhD studentsto the Bradley Lab: Margaret Cramm, Amy Solman, and Rey Mourot. Head over to the People page to learn more!
New paper in Science Advances finds widespread energy limitation to life in global subseafloor biosphere.
A new study is published in Science Advances - in which we model the global C cycle and quantify the energy regime in global subseafloor sediments. We find that the majority of microbes survive on less energy than has previously been shown to support life.
Bradley J, Arndt S, Amend J, Burwicz E, Dale A, Egger M, LaRowe D. (2020) Widespread energy limitation to life in global subseafloor sediments. Science Advances. doi: 10.1126/sciadv.aba0697
James discussed the environmental impact of the coronavirus pandemic in a recent QMUL Public Lecture.
A key point from the discussion: coronavirus has clearly demonstrated that swift and decisive global action is possible when faced with a crisis. Climate change, then, has never been treated as a crisis.
A new study led by Doug LaRowe published in GCA - in which we quantify organic carbon degradation in global subseafloor sediments over the last 2.6 million years, and make a first pass at the microbial activity it supports.
LaRowe D, Arndt S, Bradley J, Burwicz E, Dale A, Amend J (2020) Organic carbon and microbial activity in marine sediments on a global scale throughout the Quaternary. Geochimica et Cosmochimica Acta. doi: 10.1016/j.gca.2020.07.017