TY - JOUR A1 - Weißhaupt, Petra A1 - Pritzkow, Wolfgang A1 - Noll, Matthias T1 - Nitrogen sources of oligoporus placenta and trametes versicolor evaluated in a 2³ experimental plan JF - Fungal biology N2 - Four full-factorial 2³ experimental plans were applied to evaluate the nitrogen (N) sources of Oligoporus placenta and Trametes versicolor and their interaction with the atmospheric N2-assimilating bacterium Beijerinckia acida. The effects of N from peptone, of sapwood and of N from gaseous N2 on fungal, bacterial and fungal–bacterial activity were investigated. The activities were determined by quantification of biomass, formation of CO2, consumption of O2 and laccase activity. The significance of each effect was tested according to t-test recommendation. The activity of both fungi was enhanced by peptone rather than sapwood or gaseous N2. Nevertheless, comparative studies under an N2-free gas mixture as well as under air revealed that the presence of N2 affected bacterial growth and bacterial–fungal cocultivations. Elemental analysis isotope ratio mass spectrometry (IRMS) of the bacterial and fungal biomass enabled estimation of N transfer and underlined gaseous N2 as requisite for fungal–bacterial interactions. Combining full-factorial experimental plans with an analytical set-up comprising gas chromatography, IRMS and enzymatic activity allowed synergistic effects to be revealed, fungal N sources to be traced, and symbiotic fungal–bacterial interactions to be investigated. KW - Basidiomycetes KW - Diazotroph KW - Full-factorial experimental plan KW - Fungal–bacterial interaction KW - Nitrogen KW - Wood decomposition PY - 2012 DO - https://doi.org/10.1016/j.funbio.2011.10.002 SN - 1878-6146 SN - 1878-6162 VL - 116 IS - 1 SP - 81 EP - 89 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-25211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weißhaupt, Petra A1 - Naumann, Annette A1 - Pritzkow, Wolfgang A1 - Noll, Matthias T1 - Nitrogen uptake of hypholoma fasciculare and coexisting bacteria JF - Mycological progress N2 - The white-rot fungus Hypholoma fasciculare coexists with a bacterial community that uses low-molecular weight carbon sources provided by fungal, extracellular enzyme activities. Since fungal development on wood is limited by the availability of nitrogen (N), bacteria could contribute to the N supply. To prove or disapprove an interaction in terms of N transfer, N sources of the fungus and the coexisting bacterial isolates were investigated, and the bacterial N2 fixation was quantified. Fungal, fungal—bacterial and bacterial wood decomposition was analysed by Fourier transform infrared spectroscopy (FTIR), mass loss and surface pH. Microbial N preferences were investigated by elemental analysis isotope ratio mass spectrometry (IRMS). In addition, diazotrophic activity was explored after cultivation under a 15N2/O2 atmosphere. Decomposition was similar with and without bacteria and both H. fasciculare and coexisting bacteria preferred reduced N species, such as urea, ammonium and organic N. In most of the bacteria, the 15N abundance in the biomass increased significantly but to a low extent if they were cultivated under a 15N2/O2 atmosphere. This effect is considered an artefact and attributed to adsorption rather than to bacterial N2 fixation activity. Hence, the bacteria coexisting with H. fasciculare rather competed for the same N sources than supported fungal N supply by diazotrophic activity. KW - Hypholoma fasciculare KW - Proteobacteria KW - Fungal-bacterial interaction KW - 15N2 fixation KW - FTIR-ATR spectroscopy KW - IRMS PY - 2013 DO - https://doi.org/10.1007/s11557-012-0834-x SN - 1617-416X SN - 1861-8952 VL - 12 IS - 2 SP - 283 EP - 290 PB - Springer CY - Heidelberg AN - OPUS4-28867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 JF - International Journal of Mass Spectrometry 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 DO - 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 -