Research Group Loy

Research Topic

Microbial Ecology of Arctic Marine Ecosystems

Research Interest

We are studying the biogeography and ecosystem function of microorganisms in permanently cold marine sediments. Particular research interests include the ecology of psychrophilic sulfate-reducing microorganisms, ubiquitous inhabitants of anoxic sediments and key catalysts of the marine sulfur and carbon cycles. We further study anaerobic, thermophilic bacteria that rest as dormant spores on the seafloor and appear to derive from hot subsurface environments such as oil/gas deposits. These dormant bacteria hold general clues about dispersal in the ocean and are potentially useful bioindicators in fossil fuel exploration.


  • Ken Wasmund, Postdoc (University of Vienna)
  • Claus Pelikan, PhD student (University of Vienna)


Selected Publications

  • Robador A, Müller AL, Sawicka JE, Berry D, Hubert C, Loy A, Jørgensen BB, Brüchert V (2016) Activity and community structures of sulfate-reducing microorganisms in polar, temperate and tropical marine sediments. ISME Journal. 10: 796–809. doi: 10.1038/ismej.2015.157
  • Müller AL, de Rezende JR, Hubert C, Kjeldsen KU, Lagkouvardos I, Berry D, Jørgensen BB, and Loy A (2014) Endospores of thermophilic bacteria as tracers of microbial dispersal by ocean currents. ISME Journal. 8: 1153-1165.
  • Hubert C, Arnosti C, Brüchert V, Loy A, Vandieken V, and Jørgensen BB (2010) Thermophilic anaerobes in Arctic marine sediments induced to mineralize complex organic matter at high temperature. Environ Microbiol. 12: 1089-1104.
  • Hubert C, Loy A, Nickel M, Arnosti C, Baranyi C, Brüchert V, Ferdelman T, Finster K, Christensen FM, de Rezende JR, Vandieken V, and Jørgensen BB (2009) A constant flux of diverse thermophilic bacteria into the cold arctic seabed. Science. 325:1541-1544.


  • Missing links in the marine sulfur cycle – identity and functions of microorganisms utilizing sulfur cycle intermediates and organic sulfur molecules in marine sediments. FWF Austrian Science Fund [2016-2019] PI Kenneth Wasmund
  • The cold microbial majority: Ecophysiology, biogeography, and genomics of psychrophilic sulfate-reducing microorganisms in arctic marine sediments. FWF Austrian Science Fund [2013-2018] PI Alexander Loy
  • Diversity and biogeography of thermophilic sporeforming sulfate-reducing microorganisms in cold marine sediments: Bioindicators for fluid flow from the hot subsurface? FWF Austrian Science Fund [2007-2012] PI Alexander Loy


Svalbard Fjord 2010

Svalbard Fjord 2010

Svalbard glacier 2005

Svalbard Glacier 2005

Svalbard marine sediment core 2005

Svalbard marine sediment core 2005