Differential Utilisation of Carbon Substrates by Bacteria and Fungi in a Tundra Soil.
Publikation/Tidskrift/Serie: Applied and environmental microbiology
Nummer: Online 10 April 2009
Förlag: American Society for Microbiology
Little is known about the contribution of bacteria and fungi to decomposition of different carbon compounds in arctic soils, which are an important carbon store and possibly vulnerable to climate warming. Soil samples from a subarctic tundra heath were incubated with (13)C-labelled glucose, acetic acid, glycine, starch and vanillin, and the incorporation of (13)C into different phospholipid (PLFA, indicative of growth) and neutral lipid fatty acids (NLFA, indicative of fungal storage) was measured after 1 and 7 days. The use of (13)C-labelled substrates allowed addition of low enough concentrations not to affect the total amount of PLFAs. The label of glucose and acetic acid was rapidly incorporated into the PLFAs in a pattern largely corresponding to the fatty acid concentration profile, while glycine and especially starch were mainly taken up by bacteria and not fungi, showing that different groups of the microbial community were responsible for substrate utilisation. The (13)C-incorporation from the complex substrates (starch and vanillin) increased over time. There was significant allocation of (13)C into the fungal NLFAs, except for starch. For glucose, acetic acid and glycine the allocation decreased over time indicating use of the storage products, whereas for vanillin incorporation into fungal NLFAs increased during the incubation. In addition to providing information on functioning of the microbial communities in an arctic soil, our study showed that the combination of PLFA and NLFA analyses yields additional information on the dynamics of substrate degradation.
- Biological Sciences
- Microbial Ecology
- ISSN: 1098-5336