Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (64)
- Vortrag (52)
- Posterpräsentation (8)
- Buchkapitel (5)
- Beitrag zu einem Sammelband (4)
- Beitrag zu einem Tagungsband (4)
- Corrigendum (1)
- Forschungsdatensatz (1)
Schlagworte
- Biofilm (13)
- Microcolonial fungi (10)
- Black fungi (8)
- Knufia petricola (7)
- Fungi (6)
- Actinomycetes (5)
- Geodermatophilaceae (5)
- Taxonomy (5)
- Biodeterioration (4)
- Biofilms (4)
Organisationseinheit der BAM
- 4 Material und Umwelt (39)
- 4.0 Abteilungsleitung und andere (38)
- 6 Materialchemie (7)
- 6.1 Oberflächen- und Dünnschichtanalyse (6)
- 7 Bauwerkssicherheit (5)
- 7.1 Baustoffe (4)
- 1 Analytische Chemie; Referenzmaterialien (3)
- 4.1 Biologische Materialschädigung (3)
- 4.2 Material-Mikrobiom Wechselwirkungen (3)
- 1.9 Chemische und optische Sensorik (2)
Paper des Monats
- ja (2)
Wildfires strongly alter soil properties, which in turn affect ecosystem recovery over extended periods, though long-term impacts are less certain. This study investigated a 14-year post-fire chronosequence in Chile’s mediterranean and temperate humid forests, revealing ecosystem-specific soil properties and nutrient recovery mechanisms. By analysing sites at successional stages, the chronosequence approach assessed temporal changes and ecosystem recovery, revealing long-term wildfire effects on soil dynamics and nutrients recovery.
Wildfires raised soil bulk density to 0.9 g cm−3 in humid temperate and 1.2 g cm−3 in mediterranean ecosystems. Mediterranean soils experienced greater compaction from organic matter loss, soil aggregate destruction, ash-clogged pores, and topsoil erosion. Soil texture shifts were ecosystem-dependent: mediterranean soils increased 10–12 % in clay and silt through ash redistribution and aggregation, while temperate soils saw sand content rise by 0.74 % and 0.32 % yearly at 0–5 and 5–10 cm depths from thermal disaggregation and erosion. Ground vegetation recovers quickly, but physical soil properties like bulk density require over 14 years to return to pre-fire conditions.
In humid temperate forests, ash input initially increased soil pH (4.8 to 5.8), reducing acidity, mitigating aluminium toxicity, while increasing nutrient availability. Base cation stocks increased in mediterranean woodlands (e.g., Ca: up to 0.41 Mg ha−1 y−1) due to ash retention, lower leaching, and ash infiltration into subsoil. Nutrient stocks in humid forests recovered slowly (Ca: 0.087–0.13 Mg ha−1 y−1) due to rainfall-driven leaching and low subsoil reserves. Carbon and N losses were restricted to the litter horizon in temperate forests, recovering via fire-resistant tree inputs, whereas mediterranean soils suffered severe C and N depletion from vegetation loss, erosion, and low N fixation.
Fire effects and recovery are ecosystem-specific, shaped by landscape, geology, hydrology, and vegetation resilience. Understanding how fire regimes affect soil and nutrient recovery is vital for improving projections in fire-prone regions.
Sub-aerial biofilms (SABs) are ubiquitous microbial communities that develop at the interface between hard surfaces and the atmosphere. Inherent SAB 'core-settlers' include phototrophic algae, cyanobacteria, heterotrophic bacteria and microcolonial fungi (MCF). SABs do not simply cover hard surfaces; they interact with them in myriads of ways and bind to the underlying substrate. Secretion of extracellular mucilage aids adhesion, while organic acids and acidic polysaccharides weather the surface. As protection against solar radiation, many members of the SAB consortia produce shielding pigments while the phototrophic inhabitants are laden with photosynthetic pigments. All absorb light of many wavelengths and in addition, the cells themselves scatter light. Both effects change the spectra of incoming radiation (including wavelengths that are converted to electricity by photovoltaic cells) and decrease its intensity. To quantify these effects on SABs as complex entities of organisms and pigments, we measured the spectral properties of model and natural biofilms transferred to glass. Here we show that SABs growing on solar panels and other substrates scatter incident radiation between 250 nm up to 1800 nm and block up to 70% of its transmission. Model biofilms have the advantage that their microbial components can be 'tuned' to resemble natural ones of different compositions thus providing a novel materials-testing tool.
Black fungi are no longer viewed as neglected, rare, or exotic fungi—in fact, we now realize that they are all around us on a daily basis. In the past, we just have been looking at the wrong places, with inadequate detection tools, or with inappropriate isolation methods. In a way, the seemingly ubiquitous presence of black fungi is disturbing, reflecting one of the bright/dark contrasts of our research field: while scientists in the black yeast area all recognize the frustration of projects being rejected because of supposed societal insignificance, the general public tends to be afraid of these dangerous and omnipresent fungi. This fear dates back to 1934 when K. Kano described Hormiscium dermatitidis from a disfiguring facial infection in Japan. Since that time, many more severely mutilating and eventually fatal infections in apparently healthy people have been reported; the present issue of Mycopathologia contains another horrid example. Later, it was realized that these infections are related to diseases like chromoblastomycosis and primary cerebritis, which are already known for more than a century. Thus, severe black yeast diseases occurred long before organ transplantation was even invented, and in times when immune disorders like leukemia inevitably were rapidly followed by death. Black fungi belong to nature’s repertoire of primary pathogens, it seems, because they are able to kill healthy and immunocompetent individuals.
A novel Gram-positive, multiloculated thalli-forming, aerobic, actinobacterial strain, CF9/1/1T, was isolated in 2007 during environmental screening for xerophilic fungi in arid desert soil from the Sahara desert, Chad. The isolate grew best at a temperature range of 20–35 °C and at pH 6.0–8.5 and with 0–4% (w/v) NaCl, forming black-coloured and irregular colonies on GYM agar. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The DNA G+C content of the novel strain was 75.4 mol%. The peptidoglycan contained meso-diaminopimelic acid as a diagnostic diamino acid. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, a not yet structurally identified aminophospholipid and a small amount of phosphatidylglycerol; MK-9(H4) was identified as the dominant menaquinone and galactose was a diagnostic sugar. The major cellular fatty acids were branched-chain saturated acids: iso-C16:0 and iso-C15:0. The 16S rRNA gene sequence of the isolate showed 94.697.0% sequence similarities with those of five members of the genus: Geodermatophilus ruber DSM 45317T (94.6%), Geodermatophilus obscurus DSM 43160T (94.8%), Geodermatophilus siccatus DSM 45419T (96.2%), Geodermatophilus nigrescens DSM 45408T (96.7%) and Geodermatophilus arenarius DSM 45418T (97.0%). Based on the evidence from this polyphasic taxonomic study, a novel species, Geodermatophilus telluris sp. nov., is proposed; the type strain is CF9/1/1T (=DSM 45421T=CCUG 62764T).