Michael Hügler

• Dr. rer. nat.
• Senior Researcher at DVGW - Technologiezentrum Wasser

With the 2030 Agenda for Sustainable Development, the United Nations have esta-blished a catalog of 17 Sustainable Development Goals (SDGs) to achieve a better and more sustainable future for all by 2030. One important aspect, formulated as Goal 6, is ensuring the availability and sustainable management of water and sanitation for all. Achieving SD...

Worldwide, surface waters like lakes and reservoirs are one of the major sources for drinking water production, especially in regions with water scarcity. In recent years, increased numbers of coliform bacteria have been observed in these surface waters. In our monitoring study we analyzed two drinking water reservoirs (Klingenberg and Kleine Kinzi...

Certain strains of coliform bacteria have been shown to proliferate in the oligotrophic water of drinking water reservoirs and lakes, reaching values above 10 ⁴ per 100 mL. Such high concentrations challenge drinking water treatment, and occasionally the respective coliform bacteria have been detected in the treated drinking water.

Microbial water quality is routinely examined using the fecal indicator bacteria Escherichia coli, coliform bacteria and enterococci. Several practical cases in German drinking water distribution systems indicated invertebrates such as insects or gastropods as a source for the microbiological deterioration. Therefore, we examined three genera of Ga...

Most microorganisms cannot be cultured in isolation, necessitating sophisticated methods for studying their (eco)physiology. While numerous approaches can probe the activity of given microbes in enrichment cultures, no single technique can render simultaneous data on both metabolic capacities and mobile genetic elements. Here, we apply long-read se...

El proyecto NEWA-LIMA “Nuevos recursos hídricos y tratamiento innovador de aguas residuales para regiones metropolitanas áridas, tomando como ejemplo Lima, Perú”, financiado por el Ministerio del Ambiente de Alemania (BMUV) durante el período 2022 a 2024 tuvo como objetivo demostrar que la Recarga Gestionada de Acuíferos es un método natural y de b...

Lima zählt zu den trockensten Metropolregionen der Welt, so dass die Wasserversorgung der 10 Mio. Einwohner zzgl. Industrie sowie Gewerbe eine enorme Herausforderung darstellt und in den kommenden Jahren sehr große Investitionen erfordert. Die lokalen Flüsse führen nur während der Regenzeit in den Anden für wenige Monate im Jahr Wasser und die Grun...

Aquatic ecosystems house a significant fraction of Earth’s biosphere, yet most prokaryotes inhabiting these environments remain uncultivated. While recently developed genome-resolved metagenomics and single-cell genomics techniques have underscored the immense genetic breadth and metabolic potential residing in uncultivated Bacteria and Archaea, cu...

Environmental oligotrophic bacteria are suspected to be highly relevant carriers of antimicrobial resistance (AMR). However, there is a lack of validated methods for monitoring in the aquatic environment. Since extended-spectrum β-lactamases (ESBLs) play a particularly important role in the clinical sector, a culturing method based on R2A-medium sp...

We report the draft genome sequences of Buttiauxella spp. strains that were isolated from water and gastropods. Three isolates show fluorescence in the Colilert system, indicating unusual β-d-glucuronidase activity, and phylogenetic analyses suggest that they represent a novel species. Another strain, without β-d-glucuronidase activity, was assigne...

Dieser Leitfaden soll Hilfestellung bei der Konzeption, dem Aufbau und dem Betrieb von Schulungs- und Pilotanlagen geben, die im öffentlichen Raum implementiert werden. Solche Pilotanlagen erfordern von Beginn an eine soziale Einbettung und sollten daher in einem partizipativen Prozess in enger Kooperation mit den lokalen Akteuren entwickelt und um...

Video presentation on the transdiciplinary drinking water and waste water management concepts, developed jointly with the Andean highland community Tupicocha, Peru. Link: https://vimeo.com/615899049

Surface waters are a major source for drinking water production. Therefore, it is essential to examine microbial processes within the water bodies, such as mass proliferations of coliform bacteria. Here, we report the draft genome sequences of Enterobacter spp., Lelliottia spp., and Serratia spp. isolated from drinking water reservoirs and lakes.

Con la Agenda 2030 para el Desarrollo Sostenible, las Naciones Unidas han establecido un catálogo de 17 Objetivos de Desarrollo Sostenible (ODS) para lograr un futuro mejor y más sostenible para todos en 2030. Un aspecto importante, formulado como Objetivo 6, es garantizar la disponibilidad de agua y su gestión sostenible y el saneamiento para todo...

Worldwide, surface waters like lakes and reservoirs are one of the major sources for drinking water production, especially in regions with water scarcity. In the last decades, they have undergone significant changes due to climate change. This includes not only an increase of the water temperature but also microbiological changes. In recent years,...

Introduction: Microbial water quality is examined using bacterial indicators such as coliform bacteria, Escherichia coli and enterococci. Their detection indicates a possible fecal contamination. For coliform bacteria this concept has been relativized as they also occur in the environment. However, their hygienic relevance remains unclear. In recen...

Introduction: Coliform bacteria are indicators for the microbial drinking water quality. Identification of these indicator bacteria represents an important step during the search for a possible contamination source of drinking water. For this reason a fast and accurate method is a precondition for further decisions like e.g. boiling advices or disi...

Coupling microbial electrosynthesis to renewable energy sources can provide a promising future technology for carbon dioxide conversion. However, this technology suffers from a limited number of suitable biocatalysts, resulting in a narrow product range. Here, we present the characterization of the first thermoacidophilic electroautotrophic communi...

The water resources of Lima Metropolitan Area are exposed to considerable pressure as a result of climate change, population growth, overexploitation, and pollution. Ensuring a comprehensive supply of hygienically safe drinking water and sanitation throughout the region poses major challenges. Within the framework of the TRUST project, funded by th...

According to the UN SDG 6, the universal access to safe drinking water and sanitation should be achieved by 2030. This is especially a challenge in prosperous regions with water scarcity, like Lima/Peru. Within the TRUST project, solutions for water supply and wastewater management are developed for the catchment of the Lurín River near Lima. In t...

Due to their presence in the gut of humans and warm-blooded animals, coliform bacteria have been used as an indicator for fecal contamination in drinking water. Yet, in contrast to E. coli, coliform bacteria are not necessarily of fecal origin, as several genera are also found in natural environments and in association with plants and invertebrates...

The microbial safety of drinking water is routinely determined by testing for the presence of faecal indicator bacteria (FIB). Widely used indicators are E. coli, coliform bacteria and enterococci. Several practical cases in German water systems suggested gastropods as a source for the microbiological deterioration of drinking water. Therefore, we...

Widely used indicators for the determination of the hygienic quality of drinking water are E. coli, coliform bacteria and enterococci. While E. coli specifically indicates fecal contaminations, coliform bacteria or enterococci have also been isolated from environmental sources like plants, invertebrates or sediments. If indicator organisms are dete...

Within the EU project Aquavalens new molecular methods for a fast detection of microbiological risks have been tested. These methods for pathogen and indicator detection were tested in large drinking water systems under the conditions of routine laboratories. A monitoring program of 13 months in 4 large systems in Great Britain, Germany, Denmark an...

Die Wasserressourcen der Metropolregion Lima sind durch Klimawandel, Bevölkerungswachstum, Übernutzung und Verschmutzung einer erheblichen Belastung ausgesetzt. Eine flächendeckende Versorgung der Bevölkerung mit hygienisch einwandfreiem Trinkwasser und Sanitärsystemen zu sichern, stellt die lokalen Verantwortlichen vor große Herausforderungen. Gem...

Worldwide, excessive reactive nitrogen in groundwater and surface waters is a growing problem, especially in areas that face rapid urbanization and industrialization. One example for environmental nitrogen pollution is the Lake Tai, China's third largest freshwater Lake, located in the Yangtze River basin. Due to the rapid development of the surrou...

Innovative solutions and planning tools for safe drinking water supply and sustainable wastewater management are the focus of the Trust project. In many prosperous regions of the world, population and economic growth in combination with competing water demand often lead to water scarcity, i.e. higher abstraction than natural regeneration. Trust tac...

The microbial safety of drinking water is routinely determined by testing for the presence of faecal indicator bacteria (FIB). Widely used indicators are E. coli, coliform bacteria and enterococci. Several practical cases in German water distribution systems suggested gastropods as a source for the microbiological deterioration of drinking water. T...

About-face for citrate synthase Classically, it is thought that citrate synthase only works in one direction: to catalyze the production of citrate from acetyl coenzyme A and oxaloacetate in the tricarboxylic acid (TCA) cycle. The TCA cycle can run in reverse to cleave citrate and fix carbon dioxide autotrophically, but this was thought to occur on...

This report presents the field evaluation of several novel microbiological detection platforms (developed as part of the Aquavalens project) in comparison to standard / conventional microbiological detection methods. The field trials were carried out in four large drinking water systems in four European countries – the UK, Germany, Denmark and Spai...

Microbial mat communities in the effluent channels of Octopus and Mushroom Springs within the Lower Geyser Basin of Yellowstone National Park have been extensively characterized. Previous studies have focused on the chlorophototrophic organisms of the phyla Cyanobacteria and Chloroflexi. However, the diversity and metabolic functions of the other p...

Schematic map of metabolic reactions of the 3-hydroxypropionate bi-cycle and enzymes involved.

Schematic presentation of the different versions of genes encoding an ATP dependent citrate lyase (CCS, CCL, and ACL) of the reductive TCA cycle. Representative organisms for each gene variant are given in blue.

List of RubisCO genes detected in the undermat metagenome, length, and sequence coverage of scaffolds as well as the BLASTp results and taxonomic affiliation.

List of Wood-Ljungdahl/reductive acetyl-CoA pathway enzyme genes in metagenome bins and reference genomes of microbial mat members.

List of genes involved in putative utliziation of proteins and amino acids by the 15 most abundant mat members based on (partial) genome/metagenomic sequence information.

List of genes affiliated with ribose utilization in (partial) genomes of the 15 most abundant mat members.

List of genes assigned to nitrogen metabolism pathways in the most abundant mat member partial genomes/reference genomes and/or metagenome dataset.

List of dissimilatory sulfite-reductase encoding genes (dsrAB) identified in the undermat metagenome, and their taxonomic affiliation.

Reference genomes used in emergent self-organizing map binning.

List of bacteriorhodopsin-related protein (Brp) and bacteriorhodopsin-related protein-like homolog protein (Blh) encoding genes identified in the undermat metagenome, and their taxonomic affiliation.

List of 3-hydroxypropionate bi-cycle key-enzyme genes in metagenome bins and reference genomes of microbial mat Chloroflexi.

List of genes assigned to sulfur metabolism pathways in the most abundant mat member partial genomes/reference genomes and/or metagenome dataset.

Genes for rTCA cycle enzymes identified in the metagenome and affiliated with Thermocrinis sp. OTU-04.

Schematic presentation of the two branches (methyl branch and carbonyl branch) of the reductive acetyl-CoA pathway. The two key-enzymes CO dehyodrogenase (CODH) and acetyl-CoA synthase (ACS) are given in red.

List of photosynthetic reaction center genes detected in the undermat metagenome, and their taxonomic affiliation.

List of rhodopsin encoding genes identified in the undermat metagenome, and their taxonomic affiliation.

List of malonyl-CoA reductase encoding genes identified in the undermat metagenome, and their taxonomic affiliation.

List of genes affiliated with lactate utilization and production found in the (partial) genomes and metagenomic dataset.

List of hydrogenase genes identified in (partial) genomes, reference genomes, and metagenome affiliated with the most abundant mat members.

Within the European project Aquavalens (grant agreement no: 311846), new analytical tools for the detection of pathogens in drinking water and water for food production are developed and tested in field studies. One of the index pathogens studied in the Aquavalens project are thermotolerant Campylobacter spp., as they are one of the most important...

List of the proteins identified in the proteome of T. ammonificans grown under nitrate reducing conditions.DOI: http://dx.doi.org/10.7554/eLife.18990.008

Accession number of the ATP citrate lyase sequences used for the reconstruction of the phylogenetic history of the enzyme presented in Figure 2 in the main text.DOI: http://dx.doi.org/10.7554/eLife.18990.019

Anaerobic thermophiles inhabit relic environments that resemble the early Earth. However, the lineage of these modern organisms co-evolved with our planet. Hence, these organisms carry both ancestral and acquired genes and serve as models to reconstruct early metabolism. Based on comparative genomic and proteomic analyses, we identified two distinc...

Significance CO 2 fixation is the most important biosynthesis process on Earth, enabling autotrophic organisms to synthesize their entire biomass from inorganic carbon at the expense of energy generated by photo- or chemotrophic processes. In the present study we demonstrate an autotrophy pathway that represents the most energy-efficient mechanism...

Bacteriophages are often used as surrogates for enteric viruses in spiking experiments to determine the efficiencies of virus removal of certain water treatment measures, like e.g. flocculation or filtration steps. Such spiking experiments with bacteriophages are indispensable if the natural virus concentrations in the raw water of water treatment...

Vestimentiferan tubeworms (siboglinid polychetes) of the genus Lamellibrachia are common members of cold seep faunal communities and have also been found at sedimented hydrothermal vent sites in the Pacific. As they lack a digestive system, they are nourished by chemoautotrophic bacterial endosymbionts growing in a specialized tissue called the tro...

type strain HB-1 is a thermophilic (T: 75°C), strictly anaerobic, chemolithoautotrophic bacterium that was isolated from an active, high temperature deep-sea hydrothermal vent on the East Pacific Rise. This organism grows on mineral salts medium in the presence of CO/H, using NO or S as electron acceptors, which are reduced to ammonium or hydrogen...

CO(2) fixation is one of the most important processes on the Earth's surface, but our current understanding of the occurrence and importance of chemolithoautotrophy in the terrestrial subsurface is poor. Groundwater ecosystems, especially at organically polluted sites, have all the requirements for autotrophic growth processes, and CO(2) fixation i...

A fast and sensitive method for the specific detection of E. coli and coliform bacteria in water samples based on the Fluorescence in situ Hybridization (FISH) technology was developed by transferring the standard slide-based FISH protocol to a filter membrane-based method. For detection and quantification two different strategies were implemented...

Anaerobic groundwater often exhibit increased concentrations of reduced iron and manganese, as well as ammonia, while oxygen and nitrate are absent. In order to produce drinking water from such groundwater, iron and manganese have to be removed. This is achieved by aeration and subsequent sand filtration. The oxidation of Mn2+ is mediated by Mn-oxi...

Monitoring of microbiological contaminants in water supplies requires fast and sensitive methods for the specific detection of indicator organisms or pathogens. We developed a protocol for the simultaneous detection of E. coli and coliform bacteria based on the Fluorescence in situ Hybridization (FISH) technology. This protocol consists of two appr...

Metallosphaera sedula (Sulfolobales, Crenarchaeota) uses the 3-hydroxypropionate/4-hydroxybutyrate cycle for autotrophic carbon fixation. In this pathway, acetyl-coenzyme A (CoA) and succinyl-CoA are the only intermediates that can be considered common to the central carbon metabolism. We addressed the question of which intermediate of the cycle mo...

Organisms capable of autotrophic metabolism assimilate inorganic carbon into organic carbon. They form an integral part of ecosystems by making an otherwise unavailable form of carbon available to other organisms, a central component of the global carbon cycle. For many years, the doctrine prevailed that the Calvin-Benson-Bassham (CBB) cycle is the...

Functional gene clone library results. (PDF)

Phylogenetic tree based on translated aclB sequences. The tree was calculated using the Neighbor-Joining method. Bootstrap values are shown as percentages of 1000 bootstrap replicates. Sequences obtained in this study are depicted in red. Scale bar represents 5% estimated sequence divergence. (TIF)

Phylogenetic tree based on translated cbbM sequences. The tree was calculated using the Neighbor-Joining method. Bootstrap values are shown as percentages of 1000 bootstrap replicates. Sequences obtained in this study are shown in yellow. Scale bar represents 10% estimated sequence divergence. (TIF)

Phylogenetic tree based on translated hynL sequences. The tree was calculated using the Maximum-Likelihood method. Bootstrap values are shown as percentages of 100 bootstrap replicates. Sequences obtained in this study are highlighted with colors. Scale bar represents 20% estimated sequence divergence. (TIF)

The shrimp Rimicaris exoculata dominates the faunal biomass at many deep-sea hydrothermal vent sites at the Mid-Atlantic Ridge. In its enlarged gill chamber it harbors a specialized epibiotic bacterial community for which a nutritional role has been proposed. We analyzed specimens from the Snake Pit hydrothermal vent field on the Mid-Atlantic Ridge...

Life at deep-sea hydrothermal vents depends on chemolithoautotrophic microorganisms as primary producers mediating the transfer of energy from hydrothermal fluids to higher trophic levels. A comprehensive molecular survey was performed with microbial communities in a mussel patch at the Irina II site of the Logatchev hydrothermal field by combining...

The acquisition of cellular carbon from inorganic carbon is a prerequisite for life and marked the transition from the inorganic to the organic world. Recent theories of the origins of life assume that chemoevolution took place in a hot volcanic flow setting through a transition metal-catalysed, autocatalytic carbon fixation cycle. Many archaea liv...

Ammonia-oxidizing archaea are ubiquitous in marine and terrestrial environments and now thought to be significant contributors to carbon and nitrogen cycling. The isolation of Candidatus "Nitrosopumilus maritimus" strain SCM1 provided the opportunity for linking its chemolithotrophic physiology with a genomic inventory of the globally distributed a...

This paper briefly recapitulates the discovery of the first deep sea hydrothermal vents and the research undertaken within the past 30 years, followed by an overview of their biological aspects. Highlighting two unique characteristics of organisms found in this exceptional habitat: their adaptation to obtain food by microbial energy transformation...

The majority of known high‐temperature hydrothermal vents occur at mid‐ocean ridges and back‐arc spreading centers, typically at water depths from 2000 to 4000 meters. Compared with 30 years of hydrothermal research along spreading centers in the deep parts of the ocean, exploration of the approximately 700 submarine arc volcanoes is relatively rec...

Seafloor hydrothermal systems related to volcanic arcs are known from several localities in the Tyrrhenian Sea in water depths ranging from 650 m (Palinuro Seamount) to less than 50 m (Panarea). At Palinuro Seamount 13 holes (

The bacterial and archaeal communities of three deep-sea hydrothermal vent systems located on the Mid-Atlantic Ridge (MAR; Rainbow, Logatchev and Broken Spur) were investigated using an integrated culture-dependent and independent approach. Comparative molecular phylogenetic analyses, using the 16S rRNA gene and the deduced amino acid sequences of...