A grand challenge for mankind is to fight climate change, which involves both reducing and reverting CO2 emissions. Soils store more carbon (C) than the atmosphere and biosphere combined, and it is microorganisms that govern whether C compounds remain in the soil, or whether they are decomposed and released to the atmosphere as CO2. Soil fungi in particular, influence C cycling via organic matter (OM) decomposition and formation of soil aggregates that are particularly important for physical C stabilization in soils. However, the relationship between fungal activity, OM properties and environment, including complexity of soil structure (i.e., arrangement of pore space in and between soil aggregates), and how each of these factors contribute to the prolonged residence of C in soils, is not well understood. Therefore, the aim of this project is to make use of an analytical approach for studying microbial OM decomposition and dynamics by integrating two novel tools in soil sciences – microfluidic chips, which mimic soil structure, and infrared spectroscopic imaging, which provides detailed information about chemical properties of materials within these chips.
The soil chips are made from transparent glass and rubber materials, and with tiny structures, hundreds of times smaller than the thickness of a single human hair, engraved in them and mimicking the complexity of real soils. Being transparent, the soil chips provide a window to the underground world of fungi. Different chips designs can simulate different levels of complexity of soil pore space and it has been shown by using fluorescent protein or bipeptide as OM and optical microscopy that the more complex the chip structures – the less OM decomposition is observed. In this Master level project (45 – 60 ECTS) project, decomposition of more complex molecules or molecule mixtures such as lignin, maize leaves or OM from real soils and its dependence on the complexity of chip structures will be studied. For this, an approach based on infrared spectroscopic imaging – a technique that can trace chemical changes in the organic substrate – will be developed.
Welcome to contact Milda Pucetaite at Dept. of Biology to discuss the project in more detail.
E-mail: milda.pucetaite@biol.lu.se