Project Details
Projekt
The significance of saprobic fungi for energy and matter turnover under varying substrate conditions - from individuals to soils
Applicant
Dr. Tessa Camenzind
Subject Area
Soil Sciences
Microbial Ecology and Applied Microbiology
Microbial Ecology and Applied Microbiology
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 465123751
The priority program Soil Systems seeks to understand the link between carbon (C) and energy fluxes in soils, which are driven by diverse microbial communities. The fate of soil C inputs not only depends on microbial C and nutrient demands, but also on the energy available in different substrates and thermodynamic constraints. In soil, C and energy turnover can be assessed by parameters targeting the whole microbiome, with powerful predictions for biogeochemical models, whereas derived explanatory power for microbial physiology is limited. In fact, common soil parameters are based on rather simple assumptions of microbial physiology, since it is challenging to evaluate them in microbes. Thus, this project aims to complement analyses in soil with more detailed knowledge on microbial physiology, analyzing C and energy turnover at the level of microbial individuals and groups. I will focus on a microbial group highly relevant for soil organic matter degradation, saprobic fungi, which are special also due to their mycelial growth form. Detailed physiological analyses in fungi combined with soil analyses will provide an integrative approach testing all hypotheses with respect to their relevance in soil: The work will address the hypotheses of the priority program (A, B, C) with special focus on saprobic fungi, specifically testing the hypotheses that- substrates differing in energy content and complexity will affect fungal C incorporation and growth efficiency (A.1, A.2)- fungi play a predominant role in C sequestration due to C enriched necromass (A.3) - variables related to C and energy use provide species-specific traits that functionally relate to soil community composition (B.1, B.2) and - nitrogen (N) availability is less relevant than C- and energy-limitations for microbial activity in complex soils (C.1). Work packages are designed to jointly approach these hypotheses using methodologies spanning different organizational levels - from individuals to soils. Along a gradient of complexity (from controlled growth media to diverse soils) fungal carbon-use efficiency (CUE), calorespirometric ratios (CR), stoichiometry and necromass formation will be analyzed in response to substrates differing in energy content and complexity, including N limitation as potential boundary condition. Beside the analysis of response variables relevant in soil science, experiments will provide direct links to the core platform by using soils, substrates and fungal isolates from these soils. These findings will add novel insights on responses in fungal physiology to varying substrate conditions, but also its relevance for soil C and energy cycling. The physiological results can further be integrated into soil measurements, providing more direct links between microbial activity and soil CUE and CR.
DFG Programme
Priority Programmes
