Alexander Loy is Professor for Microbial Communities and a research group leader at the Centre for Microbiology and Environmental Systems Science (University of Vienna, Austria).

He serves as deputy head of the Department of Microbiology and Ecosystem Science (University of Vienna), deputy operational director of the Joint Microbiome Facility (JMF, University of Vienna and Medical University of Vienna), executive committee member of the Austrian Microbiome Initiative (AMICI), faculty member of the Austrian Polar Research Institute (APRI), and senior editor of The ISME Journal.

He received his PhD in Microbiology at the Technical University of Munich in Germany. In 2003, he was awarded a Marie Curie postdoctoral fellowship to join the newly founded Department of Microbial Ecology at the University of Vienna in Austria, where he established his own research group in 2006 based on third-party grants and was Assistant Professor from 2009 to 2013 and Associate Professor from 2013 to 2017. He received his Habilitation (venia docendi) and the Young Scientist Award of the City of Vienna in 2012.

Research of the Loy group focuses on microbial ecology, including evolution and ecology of sulfur microorganisms, the function of the complex symbiotic microbiota of animals and humans in health and disease, and the development of molecular and isotope-labeling methods for studying uncultivated microorganisms in their natural environment.