Biology subjects

Voskuhl, L.

Publications and source records attributed to Voskuhl, L..

3 recordsLinked to original sources

bioRxiv2026

Virus-host interactions on volcanic ash from Mount Etna

Volcanic ash represents an extreme and dynamic habitat, yet it hosts diverse microbial communities with largely unexplored viral diversity. This study investigated bacterial and viral populations in volcanic ash from Mount Etna (Italy) collected during the eruption, focusing on microbial novelty, activity, and virus-host interactions. Taxonomic profiling revealed that Pseudomonas and Telluria were the dominant bacterial genera, both frequently detected in airborne environments. In contrast, enrichment cultures with volcanic ash were dominated by spore-forming members of the phylum Bacillota, highlighting their resilience under harsh conditions. Metagenomic analysis recovered 19 high-quality metagenome-assembled genomes, including four previously undescribed bacterial species. Replication rate estimates showed that certain taxa were metabolically active, particularly at one sampling site. The presence of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) systems with spacers matching viral sequences suggested viral predation pressure on volcanic ash. A total of 1139 viral operational taxonomic units (vOTUs) were identified, of only around half (660 vOTUs) showed similarities to known phages, underscoring the presence of novel viruses. Shared vOTUs across sites revealed the presence of both a core virome and site-specific viral populations. Virus-host predictions indicated frequent interactions with hosts from multiple Gammaproteobacterial genera. Additionally, a 336 kb jumbo phage genome exhibited extensive metabolic capabilities and genetic autonomy. Experimental work identified a unique lytic Bacillus-infecting phage ("Phoenix") with limited propagation capacity. Furthermore, prophage induction experiments revealed active, morphologically diverse temperate phages across multiple bacterial host strains. Overall, these findings highlight volcanic ash as a reservoir of microbial and viral diversity, shaped by environmental extremes and dynamic ecological interactions. HighlightsMetagenomic and cultivation experiments were used to study viruses on volcanic ash Novelty of viral and bacterial species was detected Viral-bacterial interactions in metagenomes from volcanic ash were detected Cultivatable bacteria were mainly spore-forming Bacilli species and harbored inducible prophages

microbiology↗

bioRxiv2026

A microbial seedbank from a natural oil seep accelerates hydrocarbon degradation in freshwater oil spills

Anthropogenic oil spills are a major source of hydrocarbon pollution, yet freshwater oil spills are studied less than marine once. We hypothesize that microorganisms from freshwater natural oil seeps are adapted to use oil as carbon source and could serve as a seedbank to accelerate degradation of anthropogenic oil spills. To test this, microcosms were set up using water and oil from a natural oil seep in Germany, while light oil and oil naive river water simulated an anthropogenic spill. Seven conditions combined different water types (adapted, naive) and oil types (heavy, light, mixed). Oil degradation was monitored over 81 days via reverse stable isotope labeling, and pH and microbial communities were analyzed by 16S rRNA gene amplicon sequencing at the start and end. Microcosms with adapted microbes exhibited higher oil mineralization rates. In mixed-oil incubations, simulating the application of a microbial seedbank, degradation rates were 0.26 mM/day with adapted microbes versus 0.15 mM/day in naive water. Applying seep-derived microbes to naive light-oil microcosms increased hydrocarbon mineralization by 32%. These results suggest that leveraging natural microbial seedbanks could accelerate oil weathering and reduce the environmental impact of freshwater oil spills, offering a promising strategy for spill mitigation if applied safely. ImportanceFreshwater oil spills remain poorly studied despite their substantial contribution to global hydrocarbon pollution. This study demonstrates that microbial communities from freshwater natural oil seeps are pre-adapted to degrade crude oil and can significantly enhance the breakdown of anthropogenic oil spills. Applying such microbial seedbanks increased hydrocarbon mineralization by over 30%, highlighting their potential as an effective and environmentally relevant tool for oil spill mitigation. These findings support the development of nature-based strategies to accelerate oil weathering and reduce the environmental impact of freshwater oil spills.

microbiology↗

bioRxiv2020

Short-term responses to ocean acidification: effects on relative abundance of eukaryotic plankton from the tropical Timor Sea

Anthropogenic carbon dioxide (CO2) emissions drive climate change and pose one of the major challenges of our century. The effects of increased CO2 in the form of ocean acidification (OA) on the communities of marine planktonic eukaryotes in tropical regions such as the Timor Sea are barely understood. Here, we show the effects of high CO2 (pCO2=1823{+/-}161 atm, pHT=7.46{+/-}0.05) versus in situ CO2 (pCO2=504{+/-}42 atm, pHT=7.95{+/-}0.04) seawater on the community composition of marine planktonic eukaryotes immediately and after 48 hours of treatment exposure in a shipboard microcosm experiment. Illumina sequencing of the V9 hypervariable region of 18S rRNA (gene) was used to study the eukaryotic community composition. Down-regulation of extracellular carbonic anhydrase occurred faster in the high CO2 treatment. Increased CO2 significantly suppressed the relative abundances of different eukaryotic operational taxonomic units (OTUs), including important primary producers. These effects were consistent between abundant (DNA-based) and active (cDNA-based) taxa after 48 hours, e.g., for the diatoms Trieres chinensis and Stephanopyxis turris. Effects were also very species-specific among different diatoms. Planktonic eukaryotes showed adaptation to the CO2 treatment over time, but many OTUs were adversely affected by decreasing pH. OA effects might fundamentally impact the base of marine biodiversity, suggesting profound outcomes for food web functioning in the future ocean.

ecology↗