Fungi and bacteria are the main agents for decomposition of soil organic matter (SOM) and thus respiration in soil. The influence of environmental factors on the soil microbial community has mainly been studied using biomass estimates previously. However, biomass is not an adequate proxy for active microorganisms and we have found it to be decoupled from the microorganisms actual process contribution. During my PhD, I contributed to the development of methods to determine the growth of bacteria (leucine / thymidine incorporation) and fungi (acetate in ergosterol). These methods allowed us to enhance the resolution to study the active soil microorganisms enabling the contrast between fungal and bacterial groups in unprecedented detail compared with earlier approaches. Additionally, during my postdoc research (Bangor Univ., UK), I have studied how SOM is transformed by the microbial community, via low-molecular weight C components, into respiration.
In my laboratory, we study the ecology of microorganisms in natural and engineered soil systems. We are interested in the factors influence the spatial and temporal variability in microbial communities and how they, in turn, control global biogeochemical cycles. Specifically, we are interested in assessing not only the abundance of microorganisms but rather the actively contributing ones in the opaque soil system, and also in comparing the roles of fungi and bacteria in their contribution to biogeochemical cycles.
Rousk, J., Brookes, P.C., Bååth, E., 2010. Investigating the opposing pH relationships of fungal and bacterial growth in soil. Soil Biology & Biochemistry 42, 926-934.
Rousk, J., Brookes, P.C., Glanville H., Jones, D.L., 2011. Turnover of low molecular weight dissolved organic carbon does not correlate with differences in microbial community composition or growth across a soil pH gradient. Applied and Environmental Microbiology 77, 2791-2795.
Rousk, J., Bååth, E., 2011. Growth of saprotrophic fungi and bacteria in soil A review. FEMS Microbiology Ecology (in press) DOI: 10.1111/j.1574-6941.2011.01106.x.