The limits of microbial life and the exploration of the biological demand for energy is the focus of the International Workshop on Microbial Life under Extreme Energy Limitation, held 5-9 September at Sandbjerg Manor near Sønderborg, Denmark. We invite researchers and students from different relevant disciplines to participate in the workshop in order to discuss microbial energy requirements and stimulate new thinking and new approaches. Deadline for abstract submission and application: April 1, 2022.