In subzero sediments off the island of Spitsbergen, scientists from the German Max Planck Institute for Marine Microbiology have detected high numbers of thermophilic (heat-loving) bacteria that are adapted to live in much warmer habitats.
Experimental incubations at 40 to 60 degrees Celsius revive the Arctic spores, which appear to have been transported from distant hot spots. The discovery could shed new light on one of microbiology's great hypotheses: "Everything is everywhere, but, the environment selects."
The thermophilic spores were discovered during the Max Planck Institute's ongoing research into temperature adaptations of psychrophilic (cold-loving) bacteria in Spitsbergen's permanently cold fjords. Biological activity was measured by incubating sediment samples with labeled substrate at increasing temperatures. The scientists were impressed to see the activity increase dramatically above 40 degrees Celsius. Some dormant spores had apparently come back to life.
The results presented a unique opportunity to study misplaced microbes in a quantitative way. Using metabolic rate measurements, the researchers estimated that a single gram of the Arctic sediment contains up to 100 000 thermophilic spores. This abundance combined with the unusual location is what Max Planck Director Prof. Bo Barker Jørgensen finds exciting: "What is novel here is not the discovery of thermophiles in the Arctic, but demonstrating their high numbers and constant rate of supply." By measuring the sediment accumulation rate, the team calculated an annual deposition of 100 million thermophiles per square meter of the seabed.
So, where are the Arctic thermophiles coming from? Lead author Casey Hubert narrows down the possibilities: "The large and steady flux of anaerobic bacteria indicates that they are coming from a huge anoxic (free of oxygen) source." Transport pathways connecting these hot spots to the cold ocean must also exist. The researchers speculate fluid circulation through spreading ridges where the ocean crust forms and "black smokers" and other hydrothermal vents occur, since bacteria from these systems are genetically similar to the Arctic thermophiles. Another source could be deep hot sub-marine oil reservoirs where gas and oil leak upwards, eventually penetrating the sea floor. "The genetic similarities to bacteria from hot North Sea oil reservoirs are striking," adds Dr. Hubert. The scientists hope further experiments and genetic forensics will reveal the warm source. The spores might provide a unique opportunity to trace seepages from the hot subsurface, possibly pointing towards undiscovered offshore petroleum deposits.
In the meantime, the findings provide fresh insight for understanding marine biodiversity and the "hidden rare biosphere." Obscured by the major bacterial groups in a given environment are countless minorities that do not contribute to element cycling in any detectable way. Microbiologists continue to puzzle over how bacteria spread out to establish the vast microbial diversity that is measured in nature. The thermophilic spores appear to hold important clues about this riddle of biogeography, even as they sit dormant in the cold Arctic sediment, waiting in vain for better times.
This work was supported by the Natural Sciences and Engineering Research Council of Canada, the Max Planck Society, the Austrian Science Fund, and the National Science Foundation (US).Manfred Schlösser
For further information please contact:Casey Hubert, PhD
Department of Microbial Ecology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
Department of Marine Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3300, USA.
Department of Biological Sciences - Microbiology section, Aarhus University, Ny Munkegade, Building 1535, DK-8000 Aarhus C, Denmark.
Center for Geomicrobiology, Department of Biological Sciences, Aarhus University, Ny Munkegade, Building 1535, DK-8000 Aarhus C, Denmark.
Dr. Manfred Schloesser | Max-Planck-Gesellschaft
Nesting aids make agricultural fields attractive for bees
20.07.2017 | Julius-Maximilians-Universität Würzburg
The Kitchen Sponge – Breeding Ground for Germs
20.07.2017 | Hochschule Furtwangen
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
19.07.2017 | Event News
12.07.2017 | Event News
12.07.2017 | Event News
20.07.2017 | Information Technology
20.07.2017 | Materials Sciences
20.07.2017 | Physics and Astronomy