Salt and Metal Tolerance Involves Formation of Guttation Droplets in Species of the Aspergillus versicolor Complex

Abstract

Three strains of the Aspergillus versicolor complex were isolated from a salty marsh at a former uranium mining site in Thuringia, Germany. The strains from a metal-rich environment were not only highly salt tolerant (up to 20% NaCl), but at the same time could sustain elevated Cs and Sr (both up to 100 mM) concentrations as well as other (heavy) metals present in the environment. During growth experiments when screening for differential cell morphology, the occurrence of guttation droplets was observed, specifically when elevated Sr concentrations of 25 mM were present in the media. To analyze the potential of metal tolerance being promoted by these excretions, proteomics and metabolomics of guttation droplets were performed. Indeed, proteins involved in up-regulated metabolic activities as well as in stress responses were identified. The metabolome verified the presence of amino sugars, glucose homeostasis-regulating substances, abscisic acid and bioactive alkaloids, flavones and quinones.

Identifying biochemical constituents involved in the mycosynthesis of zinc oxide nanoparticles

“…This condition was selected because metal stress can stimulate the secretion of biomolecules in various fungal species. 26,27 As such, we hypothesized that the metabolites and proteins secreted by these fungi in response to the Zn challenge would correlate with the different of morphologies of ZnO NPs. Based on prior reports, proteinaceous material can reduce metal ions to their elemental form, 28 and/or form a protein corona around the forming nanoparticles ( protective colloid), preventing coagulation into macroscopic structures.…”

Long-Term Investigation of Marine-Derived Aspergillus Diversity in the Republic of Korea

“…Commonly isolated A. sydowii and A. versicolor were also detected in seawater and deep-sea sediment. According to their tolerance for osmotic pressure or salinity level [ 12 , 18 , 56 , 57 ], they possibly withstand other extreme or malnutrition environments. In this study, 18 Aspergillus species were isolated from seaweeds.…”

Biostimulation of indigenous microbes for uranium bioremediation in former U mine water: multidisciplinary approach assessment

“…Beta diversity was also explored in a non-metric multidimensional scaling (NMDS) matrix and Permutational analysis of variance (PERMANOVA) by Bray–Curtis dissimilarities. PAST4 (v4.04) was used to perform principal component analysis (PCA) of the Hellinger-transformed data using the relative abundances of the taxonomic composition at phylum and genus level of the two samples (three biological replicates per sample), excluding taxa with a relative abundance below 1% (Harper 1999 ).…”