Listen
Neueste Veröffentlichungen
Gerade angezeigt 1 - 5 von 191
Treffer pro Seite
Sortieroptionen
- PublikationEnvironmental selenium volatilization is possibly conferred by promiscuous reactions of the sulfur metabolism(Elsevier, 2023) Liu, Ying; Schäffer, Andreas; Martinez, Mathieu; Lenz, Markus [in: Chemosphere]Selenium deficiency affects many million people worldwide and volatilization of biogenically methylated selenium species to the atmosphere may limit Se entering the food chain. However, there is very little systematic data on volatilization at nanomolar concentrations prevalent in pristine natural environments. Pseudomonas tolaasii cultures efficiently methylated Se at these concentrations. Nearly perfect linear correlations between the spiked Se concentrations and Dimethylselenide, Dimethyldiselenide, Dimethylselenylsulfide and 2-hydroxy-3-(methylselanyl)propanoic acid were observed up to 80 nM. The efficiency of methylation increased linearly with increasing initial Se concentration, arguing that the enzymes involved are not constitutive, but methylation proceeds promiscuously via pathways of S methylation. From the ratio of all methylated Se and S species, one can conclude that between 0.30% and 3.48% of atoms were Se promiscuously methylated at such low concentrations. At concentrations higher than 640 nM (∼50 μg/L) a steep increase in methylation and volatilization was observed, which suggested the induction of specific enzymes. Promiscuous methylation at low environmental concentrations calls into question that view that methylated Se in the atmosphere is a result of a purposeful Se metabolism serving detoxification. Rather, the concentrations of methylated Se in the atmosphere may be “coincidental” i.e., determined by the activity of S cycling microorganisms. Further, a steep increase in methylation efficiency when surpassing a certain threshold concentration (here ∼50 μg/L) calls into question that natural methylation can be estimated from high Se spikes in laboratory systems, yet highlights the possibility of using bacterial methylation as an effective remediation strategy for media higher concentrated in Se. © 2023 The Authors01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationEcotoxicity attenuation by acid-resistant nanofiltration in scandium recovery from TiO2 production waste(Elsevier, 2023) Fekete-Kertész, Ildikó; Stirling, Tamás; Vaszita, Emese; Berkl, Zsófia; Farkas, Éva; Hedwig, Sebastian; Remmen, Kirsten; Lenz, Markus; Molnár, Mónika; Feigl, Viktória [in: Heliyon]01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationLarge‐scale eDNA monitoring of multiple aquatic pathogens as a tool to provide risk maps for wildlife diseases(Wiley, 11.05.2023) Sieber, Natalie; King, Alex; Krieg, Raphael; Zenker, Armin; Vorburger, Christoph; Hartikainen, Hanna [in: Environmental DNA]Multiple parasites and pathogens cause disease in aquatic wildlife and in aquaculture species, generating a need for monitoring and management. Conventional disease monitoring methods involve laborious, costly, and invasive capture and examination of host species, and require specialized expertise for every host and pathogen of interest. Environmental DNA could provide simultaneous occurrence data for multiple pathogens across different host taxa, valuable for using parasite diversity as, for example, a bioindicator of ecosystem disturbance. Here, we tested the potential for simultaneous detection of four wildlife pathogens in water samples from 280, mainly riverine, sites across Switzerland. We targeted the crayfish pathogen, the amphibian pathogen Batrachochytrium dendrobatidis, and the fish pathogens Saprolegnia parasitica and Tetracapsuloides bryosalmonae. The eDNA detection showed a widespread distribution of A. astaciS. parasitica T. bryosalmonae A. astaci and T. bryosalmonae were not detected in some alpine river catchments. B. dendrobatidis was detected only rarely, which was expected since the sampling did not target amphibian breeding sites. Co‐detection rates were higher in rivers than in lakes, likely reflecting the habitat preferences and distributions of the host species. We discuss the advantages and limitations of eDNA‐based pathogen monitoring and list a set of recommendations for managers. Our study illustrates how eDNA‐based techniques can monitor several pathogen species concurrently, thus facilitating more comprehensive disease monitoring schemes. Combined with metabarcoding approaches in the future, eDNA‐based sampling and detection can facilitate the incorporation of parasite and pathogen occurrence and diversity as an indicator for aquatic ecosystem health, and for revealing the hidden biodiversity and structure of parasite communities.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationTransforming an esterase into an enantioselective catecholase through bioconjugation of a versatile metal-chelating inhibitor(Royal Society of Chemistry, 20.06.2023) Fernandez-Lopez, Laura; Cea-Rama, Isabel; Alvarez-Malmagro, Julia; Ressmann, Anna K.; Gonzalez-Alfonso, Jose L.; Coscolín, Cristina; Shahgaldian, Patrick; Plou, Francisco J.; Modregger, Jan; Pita, Marcos; Sanz-Aparicio, Julia; Ferrer, Manuel [in: Chemical Communications]Metal complexes introduced into esterase enzyme scaffolds can generate versatile biomimetic catalysts endowed with oxidoreductase activity.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationLeaching of dissolved organic carbon from commercial reverse osmosis membranes exacerbates interferences in organic solute rejection during bench-scale filtration(Elsevier, 15.03.2023) Li, Zhao; Orlando, Adriano; Müller, Sarah I.; Ammann, Erik; Ding, An; Desmond, Peter [in: Desalination]01A - Beitrag in wissenschaftlicher Zeitschrift