Research interests in our research group

What is the microbial dark matter? I am fascinated of microbial ecology, biotechnology, and especially molecular biology, which can open the mechanisms of biogeochemical processes and functions of uncultivated microbes. My present focus is on microbes that are taking part in carbon and nitrogen cycles in natural and man-made systems, as well as on microbial communities utilizing recalcitrant humic compounds in aquatic systems. Current projects and research spans from wastewater treatment processes towards new diagnostic tools. Decades long background in molecular biology lab makes me interested especially of the cutting-edge methodologies, both in molecular and isotope fields.

Ecological questions are studied in my lab using field sampling, full-scale experimental setups and small bioreactors. Processes are measured using chromatographic techniques, using stable isotope (15N and 13C) and radioisotope markers. Molecular methods include microbial profiling methods, next-generation sequencing (NGS) analysis of ribosomal and functional genes, DNA stable and radioisotope probing, and new techniques to combine NGS and microarray techniques, including epicPCR and µRIP. In my lab works about 10-15 researchers (post-docs, PhD students and other researchers), technicians and MSc students, funded by Academy of Finland, TEKES and EU programs. We have excellent instrumentation in the department including NGS facility with actually two Ion Torrent PGM:s, two stable isotope mass spectrometers, and great imaging and clean room facilities in the NanoScience Center.

Selected recent  publications

Mäki A., Salmi P., Mikkonen A., Kremp A, Tiirola M. (2017) Sample preservation, DNA or RNA Extraction and data analysis for high-throughput phytoplankton community sequencing. Frontiers in Microbiology 8: 1848-

Saarenheimo, J., Rissanen, A. J., Arvola, L., Nykänen, H., Lehmann, M. F., & Tiirola, M. (2015). Genetic and environmental controls on nitrous oxide accumulation in lakes. PloS one, 10(3).

Larmola T., Leppänen S., Tuittila E.-S., Aarva M., Merilä P., Fritze H., Tiirola M. (2014) Methanotrophy induces nitrogen fixation during peatland development. Proc. Nat. Acad. Sci. 111:734-739