TY - JOUR A1 - Weißhaupt, Petra A1 - Pritzkow, Wolfgang A1 - Noll, Matthias T1 - Nitrogen metabolism of wood decomposing basidiomycetes and their interaction with diazotrophs as revealed by IRMS N2 - Isotope ratio mass spectrometry (IRMS) is an advanced method to investigate carbon (C) and nitrogen (N) in organic samples. In particular, the N content, its isotope signature and the C/N ratio reveal important facts of nutrient cycling, niche separation and ecological food webs. In this study, the characteristics of N turnover of wood decomposing microorganisms were investigated. The growth of the white rot causing basidiomycete Trametes versicolor is enhanced after addition of ammonia or urea, whereas the brown rot causing Oligoporus placenta is not accelerated. In addition, an interaction of each fungus with atmospheric N2 assimilating (diazotrophic) bacteria was investigated. Cultivation experiments with a gas mixture of 15N2/O2 and subsequent IRMS analysis of dry biomass of the diazotrophs Azotobacter croococcum, Beijerinckia acida and Novosphingobium nitrogenifigens revealed that they assimilated up to 12% of their N from N2. The experiments reflected N availability as a prerequisite for efficient growth of decomposing basidiomycetes and diazotrophs. Fungal–bacterial co-cultivation experiments showed that depending on the growth characteristics and bacterial N2 assimilation activity N is transferred from certain bacteria into fungal biomass. Thus, the experiments gave a first indication of an interaction between wood decomposing basidiomycetes and diazotrophs, which is a novel pathway of fungal N acquisition. KW - IRMS KW - Isotope labeling KW - Microbial interaction KW - N2 assimilation KW - Nitrogen KW - Wood decomposing basidiomycetes PY - 2011 U6 - https://doi.org/10.1016/j.ijms.2010.12.011 SN - 0168-1176 SN - 0020-7381 SN - 1387-3806 SN - 1873-2798 VL - 307 IS - 1-3 SP - 225 EP - 231 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-23307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -