Metamenu

  • Centre for Microbiology and Environmental Systems Science

  • CUBE - Computational Systems Biology

  • DOME - Microbial Ecology

  • EDGE - Environmental Geosciences

  • TER - Terrestrial Ecosystem Research

News

Latest publications

Generation of Reproducible Model Freshwater Particulate Matter Analogues to Study the Interaction with Particulate Contaminants.

Aquatic fate models and risk assessment require experimental information on the potential of contaminants to interact with riverine suspended particulate matter (SPM). While for dissolved contaminants partition or sorption coefficients are used, the underlying assumption of chemical equilibrium is invalid for particulate contaminants, such as engineered nanomaterials, incidental nanoparticles, micro- or nanoplastics. Their interactions with SPM are governed by physicochemical forces between contaminant-particle and SPM surfaces. The availability of a standard SPM material is thus highly relevant for the development of reproducible test systems to evaluate the fate of particulate contaminants in aquatic systems. Finding suitable SPM analogues, however, is challenging considering the complex composition of natural SPM, which features floc-like structures comprising minerals and organic components from the molecular to the microorganism level. Complex composition comes with a heterogeneity in physicochemical surface properties, that cannot be neglected. We developed a procedure to generate SPM analogue flocs from components selected to represent the most abundant and crucial constituents of natural riverine SPM, and the process-relevant SPM surface characteristics regarding interactions with particulate contaminants. Four components, i.e., illite, hematite, quartz and tryptophan, combined at environmentally realistic mass-ratios, were associated to complex flocs. Flocculation was reproducible regarding floc size and fractal dimension, and multiple tests on floc resilience towards physical impacts (agitation, sedimentation-storage-resuspension, dilution) and hydrochemical changes (pH, electrolytes, dissolved organic matter concentration) confirmed their robustness. These reproducible, ready-to-use SPM analogue flocs will strongly support future research on emerging particulate contaminants.

Helene Walch, Antonia Praetorius, Frank von der Kammer, Thilo Hofmann
2022 - Water Research, in press

Effect of Polymer Properties on the Biodegradation of Polyurethane Microplastics

The release of fragments from plastic products, that is, secondary microplastics, is a major concern in the context of the global plastic pollution. Currently available (thermoplastic) polyurethanes [(T)PU] are not biodegradable and therefore should be recycled. However, the ester bond in (T)PUs might be sufficiently hydrolysable to enable at least partial biodegradation of polyurethane particles. Here, we investigated biodegradation in compost of different types of (T)PU to gain insights into their fragmentation and biodegradation mechanisms. The studied (T)PUs varied regarding the chemistry of their polymer backbone (aromatic/aliphatic), hard phase content, cross-linking degree, and presence of a hydrolysis-stabilizing additive. We developed and validated an efficient and non-destructive polymer particle extraction process for partially biodegraded (T)PUs based on ultrasonication and density separation. Our results showed that biodegradation rates and extents decreased with increasing cross-linking density and hard-segment content. We found that the presence of a hydrolysis stabilizer reduced (T)PU fragmentation while not affecting the conversion of (T)PU carbon into CO2. We propose a biodegradation mechanism for (T)PUs that includes both mother particle shrinkage by surface erosion and fragmentation. The presented results help to understand structure–degradation relationships of (T)PUs and support recycling strategies.

Patrizia Pfohl, Daniel Bahl, Markus Rückel, Marion Wagner, Lars Meyer, Patrick Bolduan, Glauco Battagliarin, Thorsten Hüffer, Michael Zumstein, Thilo Hofmann, Wendel Wohlleben
2022 - Environ. Sci. Technol., in press

Both abundant and rare fungi colonizing Fagus sylvatica ectomycorrhizal root-tips shape associated bacterial communities

Ectomycorrhizal fungi live in close association with their host plants and form complex interactions with bacterial/archaeal communities in soil. We investigated whether abundant or rare ectomycorrhizal fungi on root-tips of young beech trees (Fagus sylvatica) shape bacterial/archaeal communities. We sequenced 16S rRNA genes and fungal internal transcribed spacer regions of individual root-tips and used ecological networks to detect the tendency of certain assemblies of fungal and bacterial/archaeal taxa to inhabit the same root-tip (i.e. modularity). Individual ectomycorrhizal root-tips hosted distinct fungal communities associated with unique bacterial/archaeal communities. The structure of the fungal-bacterial/archaeal association was determined by both, dominant and rare fungi. Integrating our data in a conceptual framework suggests that the effect of rare fungi on the bacterial/archaeal communities of ectomycorrhizal root-tips contributes to assemblages of bacteria/archaea on root-tips. This highlights the potential impact of complex fine-scale interactions between root-tip associated fungi and other soil microorganisms for the ectomycorrhizal symbiosis.

Dietrich M, Montesinos-Navarro A, Gabriel R, Strasser F, Meier DV, Mayerhofer W, Gorka S, Wiesenbauer J, Martin V, Weidinger M, Richter A, Kaiser C, Woebken D
2022 - Commun Biol, 5: 1261

Lecture series

CMESS Lecture: "Going Underground: Unearthing the Role of the Soil Microbiome in a Warmer, Fertilized World"

Serita Frey
Professor of Natural Resources and the Environment, University of New Hampshire, USA
01.12.2022
12:00 h
hybrid, UBB HS 1

EDGE Lecture: Where microbes meet metals, minerals and magnetism

Dr. James M. Byrne
University of Bristol, UK
01.12.2022
16:45 h
2B201, UZA2

EDGE Lecture: Clustering Methods with Potential Applications in Geosciences

Prof. Claudia Plant
University of Vienna
12.01.2023
16:45 h
2B201, UZA2