Publications by authors named "Kallies R"

Draft genomes of two phenanthrene-degrading bacterial isolates from oil sands process-affected water (OSPW) in Alberta, Canada were sequenced. Both isolates grew in close association on agar plates and were difficult to obtain axenically. They represent novel and sp.

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  • Hepatitis E virus (HEV) is a global concern that can lead to long-lasting infections and serious health issues, with antiviral treatments potentially causing resistance through viral mutations.
  • A study conducted in North-Rhine Westphalia, Germany found that 73% of environmental samples, including wastewater and river water, were positive for HEV RNA, indicating a high prevalence.
  • Through high-throughput sequencing, researchers discovered significant genetic diversity among HEV variants, including those linked to drug resistance, highlighting the importance of monitoring these variants for better treatment management.
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  • The study investigates the role of small intestinal bacterial overgrowth and changes in gut microbiota in patients with liver cirrhosis, linking them to bacterial translocation and potential infections.
  • Researchers analyzed duodenal samples and bacterial DNA from 103 cirrhosis patients compared to 22 non-liver disease controls, using advanced genetic sequencing techniques.
  • Results showed that cirrhosis patients had unique bacterial profiles in the duodenum, marked by higher levels of certain bacteria like Streptococcus, while overall bactDNA levels in blood and duodenal fluid were similar to controls, suggesting a specific dysbiosis associated with liver disease.
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Huge phages have genomes larger than 200 kilobases, which are particularly interesting for their genetic inventory and evolution. We screened 165 wastewater metagenomes for the presence of viral sequences. After identifying over 600 potential huge phage genomes, we reduced the dataset using manual curation by excluding viral contigs that did not contain viral protein-coding genes or consisted of concatemers of several small phage genomes.

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  • The introduction of hydrogen gas into a shallow aquifer showed significant changes in biogeochemical processes, including increased acetate concentrations and shifts in microbial diversity.
  • The study highlighted that hydrogen, when leaked, quickly impacts the groundwater microbiome, leading to temporary alterations in microbial populations that thrive on hydrogen.
  • Once hydrogen levels returned to normal, the microbial diversity and conditions in the aquifer reverted to baseline, suggesting that hydrogen is efficiently consumed by microbes in the environment.
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Several computational frameworks and workflows that recover genomes from prokaryotes, eukaryotes and viruses from metagenomes exist. Yet, it is difficult for scientists with little bioinformatics experience to evaluate quality, annotate genes, dereplicate, assign taxonomy and calculate relative abundance and coverage of genomes belonging to different domains. MuDoGeR is a user-friendly tool tailored for those familiar with Unix command-line environment that makes it easy to recover genomes of prokaryotes, eukaryotes and viruses from metagenomes, either alone or in combination.

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  • Wastewater monitoring for SARS-CoV-2 is an effective method for tracking virus spread and predicting infection rates in populations.
  • Recent studies show that passive samplers, which collect virus samples over time, can detect SARS-CoV-2 in wastewater more efficiently than traditional methods.
  • In a study conducted in Leipzig, results indicated that these passive samplers provided accurate data at both city and district levels, making them a valuable tool for wastewater-based epidemiology and infection estimation.
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  • Cyanobacteria are gaining attention in biotechnology, particularly for genetic engineering and innovative reactor designs like capillary biofilm reactors (CBRs), which enhance cell growth.
  • Strain PCC 7712 has been identified as ideal for CBRs due to its excellent biofilm attachment and high biomass yield, prompting the complete genome sequencing of both PCC 7712 and a related strain, PCC 7601.
  • Despite their nearly identical genomes, differences in protein-coding sequences and nitrogen fixation abilities were observed between the two strains, indicating potential for targeted strain engineering.
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  • Extreme temperature gradients in polar volcanoes help select various extremophiles, particularly in areas like Deception Island, which exhibits temperature variations from 100°C to subzero.
  • A study focused on isolating thermophilic bacteria from geothermal sediments showed that 126 bacterial strains were identified, with 76 capable of growing on crude oil and 30 demonstrating effective hydrocarbon degradation.
  • Four strains showed excellent crude oil degradation capabilities, with one strain identified as having significant potential for biotechnological applications, including bioremediation and microbial enhanced oil recovery in extreme environments.
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On their way from inland to the ocean, flowing water bodies, their constituents and their biotic communities are exposed to complex transport and transformation processes. However, detailed process knowledge as revealed by Lagrangian measurements adjusted to travel time is rare in large rivers, in particular at hydrological extremes. To fill this gap, we investigated autotrophic processes, heterotrophic carbon utilization, and micropollutant concentrations applying a Lagrangian sampling design in a 600 km section of the River Elbe (Germany) at historically low discharge.

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  • Recent studies show that phages can be transported with non-host bacteria, helping them invade biofilms and influence their composition.
  • The research developed a method to isolate these bacteria from soil, using their ability to move with phages along mycelia and form colonies.
  • Five types of bacteria were identified, with some demonstrating high efficiency in adsorbing phages, particularly one species that excelled as a "super carrier" for both tested phages.
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The draft genome sequences of two strains that are hexachlorocyclohexane (HCH) degraders are presented. The strains were isolated from HCH-contaminated soil in Kitengela, Kenya. Both genomes possess the genes responsible for HCH degradation and gene clusters for degradation of other xenobiotic compounds.

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  • Marine phages, specifically Pseudoalteromonas phages PSA-HM1 and PSA-HS2, demonstrate effective tracking capabilities in soil and sand environments, comparable to Escherichia virus T4.
  • Both marine phages showed higher transport velocities and mass recoveries than the non-reactive tracer Br.
  • The study highlights that marine phages maintain better particle intactness than T4 and could be useful for tracking environmental transport of colloids or nanoparticles, with quantitative PCR (qPCR) providing sensitive detection methods.
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  • Nonmotile microorganisms, like lytic phages, can hitch a ride with motile bacteria (like Pseudomonas putida) to colonize new environments, similar to how invasive species operate in macroecology.
  • Researchers created microcosms with hyphae from Pythium ultimum, showing that these hyphae help the bacteria transport phages effectively to new habitats—specifically, P. putida spread the bacteriophage T4 to new areas.
  • The presence of T4 phages improved the ability of P. putida to thrive in areas also occupied by E. coli while their absence hindered colonization, highlighting the crucial role of bacteria and phages in shaping microbial communities in soil environments.
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We present the draft genome sequence of Fusarium equiseti strain K3, a fungus isolated from a hexachlorocyclohexane (HCH)-contaminated soil (Kitengela, Kenya). The 37.88-Mb draft genome sequence consists of 206 contigs, 12,311 predicted protein-coding sequences, and 261 tRNA sequences.

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The high complexity found in microbial communities makes the identification of microbial interactions challenging. To address this challenge, we present OrtSuite, a flexible workflow to predict putative microbial interactions based on genomic content of microbial communities and targeted to specific ecosystem processes. The pipeline is composed of three user-friendly bash commands.

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  • Ljungan virus (LV) has been found in various small mammal species across Europe, but research on its genetic diversity and host preferences is limited.
  • The study analyzed the genetic relationships of LV variants by examining specific viral regions in 24 infected animals, leading to the identification of three new genotypes in bank and field voles.
  • The findings indicate that LV evolves quickly and is influenced by factors such as genetic drift and host history, positioning it as a potentially valuable model for studying RNA virus evolution despite its low zoonotic risk.
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In the context of environmental plastic pollution, it is still under debate if and how the "plastisphere", a plastic-specific microbial community, emerges. In this study, we tested the hypothesis that the first conditioning film of dissolved organic matter (DOM) sorbs selectively to polymer substrates and that microbial attachment is governed in a substrate-dependent manner. We investigated the adsorption of stream water-derived DOM to polyethylene terephthalate (PET), polystyrene (PS), and glass (as control) including UV-weathered surfaces by Fourier-transform ion cyclotron mass spectrometry.

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Mining interspecies interactions remain a challenge due to the complex nature of microbial communities and the need for computational power to handle big data. Our meta-analysis indicates that genetic potential alone does not resolve all issues involving mining of microbial interactions. Nevertheless, it can be used as the starting point to infer synergistic interspecies interactions and to limit the search space (i.

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Aquifer thermal energy storage (ATES) is a key concept for the use of renewable energy resources. Interest in ATES performed at high temperature (HT-ATES; > 60 °C) is increasing due to higher energetic efficiencies. HT-ATES induces temperature fluctuations that exceed the natural variability in shallow aquifers, which could lead to adverse effects in subsurface ecosystems by altering the groundwater chemistry, biodiversity, and microbial metabolic activity, resulting in changes of the groundwater quality, biogeochemical processes, and ecosystem functions.

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Use of wastewater-based epidemiology as a tool to record and manage the course of SARS-CoV-2 infections in human populations requires information about the efficiency of methods to concentrate the virus from wastewater. In the present study, we spiked untreated wastewater with quantified SARS-CoV-2 positive clinical material and enriched the virus by polyethylene glycol precipitation and ultrafiltration with Vivaspin 10 kDa MWCO columns. SARS-CoV-2 was detected and quantified by reverse transcription quantitative PCR (E- and S-gene) and droplet digital PCR.

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Meeting ecological and water quality standards in lotic ecosystems is often failed due to multiple stressors. However, disentangling stressor effects and identifying relevant stressor-effect-relationships in complex environmental settings remain major challenges. By combining state-of-the-art methods from ecotoxicology and aquatic ecosystem analysis, we aimed here to disentangle the effects of multiple chemical and non-chemical stressors along a longitudinal land use gradient in a third-order river in Germany.

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Objectives: This in vivo study compared the antibacterial effect of a self-etch adhesive with and without the brominated monomer 12-methacryloyloxydodecyl-pyridinium bromide (MDPB) on carious dentin after selective caries removal.

Methods: 10 patients showing deep primary carious lesions at two posterior teeth without pulpal symptoms were included. At visit I, carious tissue was selectively removed and carious dentin was sampled with a sterile roundbur (Komet No.

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Objectives: Selective caries removal in deep lesions means that soft carious affected dentin is left in the center of the cavity. Thus, using a tricalcium silicate cement Biodentine™ (Septodont, Paris) to seal the remaining soft dentin could have an antibacterial effect. This in-vivo study aimed to do quantitative and qualitative analyses on the bacterial composition within carious dentin before and after selective caries removal when applying Biodentine.

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