Filtern
Erscheinungsjahr
Dokumenttyp
Sprache
- Englisch (52)
Referierte Publikation
- ja (52) (entfernen)
Schlagworte
- Actinomycetes (5)
- Fungi (5)
- Geodermatophilaceae (5)
- Microcolonial fungi (5)
- Taxonomy (5)
- Black fungi (4)
- Bacteria (3)
- Biofilm (3)
- Biofilms (3)
- Biofouling (3)
- Forsterite (3)
- Knufia petricola (3)
- Phenotype microarray (3)
- Solar panels (3)
- Bio-weathering (2)
- Biodeterioration (2)
- Biogenic weathering (2)
- Bioreceptivity (2)
- Chad (2)
- Cyanobacteria (2)
- DHN melanin (2)
- Dothideomycetes (2)
- Evolution (2)
- Extracellular polymeric substances (2)
- Fouling (2)
- Geobiology (2)
- Magnesium (2)
- Phototrophs (2)
- Real-time qPCR (2)
- Sahara desert (2)
- Subaerial biofilms (2)
- Weathering (2)
- Xerophiles (2)
- (Semi)arid to humid-temperate natural ecosys (1)
- 13CO2 pulse labeling (1)
- 16S amplicons (1)
- 3D printing (1)
- A. versicolor (1)
- A95 (1)
- AFM cantilever vibration (1)
- Acetoclastic methanogenesis (1)
- Adaptation (1)
- Aeolian (1)
- Agricultural mycology (1)
- Albite (1)
- Analytical Chemistry (1)
- Antifouling (1)
- Aquatic grain corrosion (1)
- Arbuscular mycorrhiza (1)
- Arthoniomycetes (1)
- Aspergillus sydowii (1)
- Atomic and Molecular Physics and Optics (1)
- Bacterial adhesion (1)
- Biocides (1)
- Biofilm formation (1)
- Biofilm-impaired transmittance of radiation (1)
- Biological (1)
- Biological grain pitting (1)
- Biologically induced mineral weathering (1)
- Biolog system (1)
- Biomaterial (1)
- Biopitting (1)
- Biotic weathering (1)
- Black microcolonial fungi (1)
- Black yeast (1)
- Bodélé Depression (1)
- Botrytis cinerea (1)
- CEC-L-103 (1)
- CRISPR/Cas9 (1)
- Capnodiales (1)
- Chaetothyriales (1)
- Chaetothyriales (Eurotiomycetes) (1)
- Chemical grain pitting (1)
- Chilean Coastal Cordillera (1)
- Climate gradient (1)
- Cloning vectors (1)
- Community analysis or microbial diversity (1)
- Comparative genomics (1)
- Concrete (1)
- Confocal microscopy (1)
- Corrosion (1)
- Cultivation (1)
- DGGE (1)
- Desert sand (1)
- Deserts (1)
- Developing building materials (1)
- Diesel biodeterioration (1)
- Drywood termite (1)
- EPS (1)
- Ecology (1)
- Energy production (1)
- Escherichia coli (1)
- Eukaryota (1)
- Eurotiomycetes (1)
- Extracellular enzymes (1)
- Extremophiles (1)
- Extremotolerance (1)
- Fermentative bacteria (1)
- Flow-through cell (1)
- Fluorescent microscopy (1)
- Fractal structure (1)
- Fuel contamination (1)
- Fungal stress mechanisms and responses (1)
- Fungi-phototroph symbioses (1)
- Fungus (1)
- GC-FID (1)
- Genetics (1)
- Genomics (1)
- Glass biodeterioration (1)
- Graphene (1)
- Graphene–bacteria interaction (1)
- Green facades (1)
- Herpotrichiellaceae (1)
- High throughput sequencing (1)
- Image analysis (1)
- Indicator (1)
- Industrial mycology (1)
- Instrumentation (1)
- Internal pores (1)
- Isotope fractionation (1)
- Knock-out mutant (1)
- Knufia petricola (syn. Sarcinomyces petricola) (1)
- Liches (1)
- Low-molecular-weight organic substances (1)
- Marble (1)
- Material-colonising microorganisms (1)
- Medical mycology (1)
- Melanin (1)
- Melanin Adhesion (1)
- Melanised microcolonial fungi (MCF) (1)
- Melanised rock-inhabiting fungi (1)
- Metabolomics (1)
- Metagenomics (1)
- Methanosarcinales (1)
- Microbial contamination (1)
- Microbiologically influenced corrosion; (1)
- Microscopy (1)
- Mine gas (1)
- Minerals (1)
- Multi-scale study (1)
- Multigene phylogeny (1)
- N and K analog tracer (1)
- Nano-structure of grain and mineral surfaces (1)
- Nanocorrosion of aluminium and silicon (1)
- Nanoviscosity (1)
- Natural ecosystems (1)
- Nostoc punctiforme (1)
- Nutrient acquisition (1)
- Nutrient cycles (1)
- Nutrient uplift and recyclin (1)
- Olivine (1)
- Organic phosphorus breakdown (1)
- Osmotolerant (1)
- PV modules (1)
- Phosphorus K-edge-XANES spectroscopy (1)
- Photovoltaic module (1)
- Phyllosphere (1)
- Phylogeny (1)
- Physiological characterisation (1)
- Plant economic spectrum (1)
- Polymer (1)
- Pullulan (1)
- Quantitative PCR (1)
- RNA interference (1)
- Radiation-resistant (1)
- Raman Spectroscopy (1)
- Real-time quantitative PCR (1)
- Reference organisms (1)
- Republic of Chad (1)
- Rhizosphere effect (1)
- Rhizosphere processes (1)
- Rock biofilm (1)
- Rock inhabiting (1)
- Rock leaching (1)
- Rock-art caves (1)
- Rock-inhabiting fungi (1)
- Root economics space (1)
- SEM micrography (1)
- Secondary metabolites (1)
- Sediment grain corrosion (1)
- Soil formation (1)
- Sterigmatocystin (1)
- Stoichiometric homeostasis (1)
- Stone cultural heritage (1)
- Stress conditions (1)
- Stress tolerance (1)
- Sub-aerial biofilms (1)
- Sub-aerial biofilms (SAB) (1)
- Subaerial and subaquatic biofilm (1)
- Subaerial biofilm (1)
- Subsoil nutrient tracing (1)
- Surface analysis (1)
- Surface coating (1)
- Surface interactions (1)
- Symbiosis (1)
- Temperate rain forest (1)
- Tems (1)
- Transcriptomics (1)
- Transformations (1)
- Wind erosion (1)
- X-ray tomographic (1)
- XPS (1)
- α-1,4- and α-1,6-glucans (1)
Organisationseinheit der BAM
- 4 Material und Umwelt (22)
- 4.0 Abteilungsleitung und andere (21)
- 6 Materialchemie (5)
- 6.1 Oberflächen- und Dünnschichtanalyse (4)
- 4.1 Biologische Materialschädigung und Referenzorganismen (2)
- 4.2 Material-Mikrobiom Wechselwirkungen (2)
- 5 Werkstofftechnik (2)
- 5.4 Multimateriale Fertigungsprozesse (2)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.7 Organische Spuren- und Lebensmittelanalytik (1)
Paper des Monats
- ja (1)
Life at the atmosphere-lithosphere boundary is an ancient terrestrial niche that is sparsely covered by thin subaerial biofilms. The microbial inhabitants of these biofilms (a) have adapted to all types of terrestrial/subaerial stresses (e.g., desiccation, extreme temperatures, low nutrient availability, intense solar radiation), (b) interact with minerals that serve as both a dwelling and a source of mineral nutrients, and (c) provoke weathering of rocks and soil formation. Subaerial communities comprise heterotrophic and phototrophic microorganisms that support each other's lifestyle. Major lineages of eubacteria associated with the early colonization of land (e.g., Actinobacteria, Cyanobacteria) are present in these habitats along with eukaryotes such as microscopic green algae and ascomycetous fungi. The subaerial biofilm inhabitants have adapted to desiccation, solar radiation, and other environmental challenges by developing protective, melanized cell walls, assuming microcolonial architectures and symbiotic lifestyles. How these changes occurred, their significance in soil formation, and their potential as markers of climate change are discussed below.
The class Dothideomycetes (along with Eurotiomycetes) includes numerous rock-inhabiting fungi (RIF), a group of ascomycetes that tolerates surprisingly well harsh conditions prevailing on rock surfaces. Despite their convergent morphology and physiology, RIF are phylogenetically highly diverse in Dothideomycetes. However, the positions of main groups of RIF in this class remain unclear due to the lack of a strong phylogenetic framework. Moreover, connections between rock-dwelling habit and other lifestyles found in Dothideomycetes such as plant pathogens, saprobes and lichen-forming fungi are still unexplored. Based on multigene phylogenetic analyses, we report that RIF belong to Capnodiales (particularly to the family Teratosphaeriaceae s.l.), Dothideales, Pleosporales, and Myriangiales, as well as some uncharacterised groups with affinities to Dothideomycetes. Moreover, one lineage consisting exclusively of RIF proved to be closely related to Arthoniomycetes, the sister class of Dothideomycetes. The broad phylogenetic amplitude of RIF in Dothideomycetes suggests that total species richness in this class remains underestimated. Composition of some RIF-rich lineages suggests that rock surfaces are reservoirs for plant-associated fungi or saprobes, although other data also agree with rocks as a primary substrate for ancient fungal lineages. According to the current sampling, long distance dispersal seems to be common for RIF. Dothideomycetes lineages comprising lichens also include RIF, suggesting a possible link between rock-dwelling habit and lichenisation.
Worldwide, abandoned coal mines release substantial amounts of methane, which is largely of biogenic origin. The aim of this study was to understand the microbial processes involved in mine-gas formation. Therefore, coal and timber samples and anaerobic enrichments from two abandoned coal mines in Germany were subjected to DGGE analyses and quantitative PCR. The primers used were specific for Bacteria, Archaea, Fungi, and the key functional genes for sulfate reduction (dsrA) and methanogenesis (mcrA). A broad spectrum of facultative anaerobic bacteria and acetogens belonging to all five groups (α-ε) of the Proteobacteria, as well as the Bacteroidetes, Tenericutes, Actinobacteria, Chlorobi and Chloroflexi were detected. Archaea were represented by acetoclastic Methanosarcinales and Crenarchaeota with an unknown metabolism. Fungi formed thick biofilms particularly on timber, and were identified as typical wood degraders belonging to the Ascomycetes and Basidiomycetes. The community analysis as well as the environmental conditions and the metabolites detected in a previous study are consistent with the following scenario of methane release: Weathering of coal and timber is initiated by wood-degrading Fungi and Bacteria under a suboxic atmosphere. In the lower, oxygen-depleted layers Fungi and Bacteria perform incomplete oxidation and release reduced substrates which can be channeled into methanogenesis. Acetate appeared to be the main precursor of the biogenic methane in the investigated coal mines.
Three principally different mechanisms contribute to the wear-down process of mineral aggregates in sedimentary environments: (1) mechanical abrasion by forces of wind and water and by floating or saltating neighbouring grains, (2) chemical attack and dissolution by fluids, and (3) physical bioerosion and chemical biocorrosion. It is however, difficult to attribute the specific surface changes to specific environments and processes. Quartz sand grains from subaerial and subaquatic environments were analysed by atomic force microscopy (AFM) for traces of natural and experimental aeolian, aquatic and biological wear-down processes. Quantitative topographical parameters of surface alterations were extracted from topography data by non-linear methods derived from digital image analysis. These parameters were examined by multivariate statistic, yielding three well-distinguishable groups. Morphological surface alterations dominated by subaerial, subaquatic and by biological impact could be differentiated. The method may also be used for the detection of aeolian, subaquatic, and biological modification of sedimentary grains and rock surfaces in extraterrestrial environments, and for assessment of environmental damage on monuments and buildings.
Desert dust seeds distant lands and waters
with minerals as well as micro-organisms raising the
question of whether this ancient phenomenon also
spreads pathogens across the globe. Severe dust
storms require strong winds blowing over land-masses
that are largely devoid of vegetation, effectively
limiting the scope for winds to raise pathogens into
the air. Nevertheless, changing patterns of land-use,
often driven by belligerency, result in refugees
spreading to areas that were previously deemed barely
habitable. With the help of the International Committee
of the Red Cross, a number of sand/dust samples
were collected from the Republic of Chad, some near
refugee camps, others further removed from human
influence. In parallel studies, we documented the
micro-organisms present in these samples and used a
number of the isolates here to test the effect of
environmental constraints on their ability to survive
intercontinental flight. We also added traditional
pathogens to the palette of microbes and tested the
effects of UV irradiation, desiccation and temperature
on survival of both bacteria and fungi. A clear trend
was obvious—those microbes that are coloured or able
to form conidia or spores (in other words, those that
are native to deserts) were well able to resist the
imposed stresses. On the other hand, most pathogens
were more sensitive to stresses than the environmental
isolates. Toxin production in two species of Aspergillus
was also investigated. Short-term desiccation
(simulating environmental conditions during intercontinental
travel) of sand amended with fungal spores
containing sterigmatocystin leads to increased mycotoxin
contents, but significant mycotoxin production
was only possible under growth-permissive conditions,
e.g. at higher humidity. It thus seems likely that an ever-decreasing fraction of the initial pathogen load
survives as the dust recedes from its desert source and
that those organisms that land on other continents are
highly enriched in desert dwellers.
A novel Gram-positive, aerobic, actinobacterial strain, CF5/5, was isolated from soil in the Sahara desert, Chad. It grew best at 20–35 °C and at pH 6.0–8.0 and with 0–4 % (w/v) NaCl, forming black-colored colonies. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Geodermatophilus. The DNA G + C content was 75.9 mol%. The peptidoglycan contained meso-diaminopimelic acid; galactose and xylose were detected as diagnostic sugars. The main phospholipids were diphosphatidylglycerol, phosphatidylcholine, and phosphatidylinositol; MK-9(H4) was the dominant menaquinone. The major cellular fatty acids were: iso-C16:0 and iso-C15:0. The 16S rRNA gene showed 95.6–98.3 % sequence similarity with the other named members of the genus Geodermatophilus. Based on the polyphasic taxonomy data, the isolate is proposed to represent a novel species, Geodermatophilus saharensis with the type strain CF5/5T = DSM 45423 = CCUG 62813 = MTCC 11416.
A novel Gram-positive, aerobic, actinobacterial strain, CF5/4T, was isolated in 2007 during an environmental screening of arid desert soil in Ouré Cassoni, Chad. The isolate grew best in a temperature range of 2840 °C and at pH 6.0-8.5, with 0-1 % (w/v) NaCl, forming brown-coloured and nearly circular 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 75.9 mol %. The peptidoglycan contained meso-diaminopimelic acid as diagnostic diaminoacid. The main phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, diphosphatidylglycerol and a small amount of phosphatidylglycerol; MK-9(H4) was identified as the dominant menaquinone and galactose as diagnostic sugar. The major cellular fatty acids were branched-chain saturated acids: iso-C15:0 and iso-C16:0. The 16S rRNA gene showed 96.298.3 % sequence identity with the three members of the genus Geodermatophilus: G. obscurus (96.2 %), G. ruber (96.5 %), and G. nigrescens (98.3 %). Based on the chemotaxonomic results, 16S rRNA gene sequence analysis and DNA–DNA hybridization with the type strain of G. nigrescens, the isolate is proposed to represent a novel species, Geodermatophilus arenarius (type strain CF5/4T = DSM 45418T = MTCC 11413T = CCUG 62763T).
A novel Gram-positive, aerobic, actinobacterial strain, CF6/1T, was isolated in 2007 during environmental screening of arid desert soil in the Sahara near to Ourba, Chad. The isolate was found to grow best in a temperature range of 20–37 °C and at pH 6.0–8.5 and showed no NaCl tolerance, forming black-coloured and nearly circular colonies on GYM agar. Chemotaxonomic and molecular characteristics determined for the isolate match those previously described for members of the genus Geodermatophilus. The DNA G + C content of the novel strain was determined to be 74.9 mol %. The peptidoglycan was found to contain meso-diaminopimelic acid as the diagnostic diamino acid. The main phospholipids were determined to be phosphatidylethanolamine, phosphatidylinositol, phosphatidylcholine, diphosphatidylglycerol and traces of phosphatidylglycerol; MK-9(H4) was identified as the dominant menaquinone and galactose as the diagnostic sugar. The major cellular fatty acids were found to be the branched-chain saturated acids iso-C16:0 and iso-C15:0, as well as C17:1ω8c. The 16S rRNA gene sequence shows 97.5–97.9 % sequence identity with the four validly named or at least effectively published members of the genus: Geodermatophilus obscurus (97.5 %), Geodermatophilus arenarius (97.7 %), Geodermatophilus ruber (97.9 %) and Geodermatophilus nigrescens (97.9 %). Based on the results from this polyphasic taxonomic analysis and DNA–DNA hybridizations with all type strains of the genus, we propose that strain CF6/1T represents a novel species, Geodermatophilus siccatus, with the type strain CF6/1T = DSM 45419T = CCUG 62765T = MTCC 11414T.
Ancient mariners knew that dust whipped up from deserts by strong winds travelled long distances, including over oceans. Satellite remote sensing revealed major dust sources across the Sahara. Indeed, the Bodélé Depression in the Republic of Chad has been called the dustiest place on earth. We analysed desert sand from various locations in Chad and dust that had blown to the Cape Verde Islands. High throughput sequencing techniques combined with classical microbiological methods showed that the samples contained a large variety of microbes well adapted to the harsh desert conditions. The most abundant bacterial groupings in four different phyla included: (a) Firmicutes—Bacillaceae, (b) Actinobacteria—Geodermatophilaceae, Nocardiodaceae and Solirubrobacteraceae, (c) Proteobacteria—Oxalobacteraceae, Rhizobiales and Sphingomonadaceae, and (d) Bacteroidetes—Cytophagaceae. Ascomycota was the overwhelmingly dominant fungal group followed by Basidiomycota and traces of Chytridiomycota, Microsporidia and Glomeromycota. Two freshwater algae (Trebouxiophyceae) were isolated. Most predominant taxa are widely distributed land inhabitants that are common in soil and on the surfaces of plants. Examples include Bradyrhizobium spp. that nodulate and fix nitrogen in Acacia species, the predominant trees of the Sahara as well as Herbaspirillum (Oxalobacteraceae), a group of chemoorganotrophic free-living soil inhabitants that fix nitrogen in association with Gramineae roots. Few pathogenic strains were found, suggesting that African dust is not a large threat to public health.
Three novel Gram-positive, aerobic, actinobacterial strains, CF5/2T, CF5/1 and CF7/1, were isolated in 2007 during environmental screening of arid desert soil in the Sahara desert, Chad. Results from riboprinting, MALDI-TOF protein spectra and 16S rRNA sequence analysis confirmed that all three strains belonged to the same species. Phylogenetic analysis of 16S rRNA sequences with the strains' closest relatives indicated that they represented a distinct species. The three novel strains also shared a number of physiological and biochemical characteristics distinct from previously named Geodermatophilus species. The novel strains' peptidoglycan contained meso-diaminopimelic acid; their main phospholipids were phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol and a small amount of phosphatidylglycerol; MK-9(H4) was the dominant menaquinone. The major cellular fatty acids were the branched-chain saturated acids iso-C16:0 and iso-C15:0. Galactose was detected as diagnostic sugar. Based on these chemotaxonomic results, 16S rRNA gene sequence analysis and DNA–DNA hybridization between strain CF5/2T and the type strains of Geodermatophilus saharensis, Geodermatophilus arenarius, Geodermatophilus nigrescens, Geodermatophilus telluris and Geodermatophilus siccatus, the isolates CF5/2T, CF5/1 and CF7/1 are proposed to represent a novel species, Geodermatophilus tzadiensis, with type strain CF5/2T = DSM 45416 = MTCC 11411 and two reference strains, CF5/1 (DSM 45415) and CF7/1 (DSM 45420).