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Hugenholtz, Philip

Publications and source records attributed to Hugenholtz, Philip.

A comparative genome analysis of the Bacillota ( Firmicutes ) class Dehalobacteriia

Dehalobacterium formicoaceticum is recognized for its ability to anaerobically ferment dichloromethane (DCM), and a catabolic model has recently been proposed. D. formicoaceticum is currently the only axenic representative of its class, the Dehalobacteriia, according to the Genome Taxonomy Database. However, substantial additional diversity has been revealed in this lineage through culture-independent exploration of anoxic habitats. Here we performed a comparative analysis of 10 members of the Dehalobacteriia, representing three orders, and infer that anaerobic DCM degradation appears to be a recently acquired trait only present in some members of the order Dehalobacteriales. Inferred traits common to the class include the use of amino acids as carbon and energy sources for growth, energy generation via a remarkable range of putative electron-bifurcating protein complexes and the presence of S-layers. The ability of D. formicoaceticum to grow on serine without DCM was experimentally confirmed and a high abundance of the electron-bifurcating protein complexes and S-layer proteins was noted when this organism was grown on DCM. We suggest that members of the Dehalobacteriia are low-abundance fermentative scavengers in anoxic habitats.

59 BASIC BIOLOGICAL SCIENCES↗

Metagenomic compendium of 189,680 DNA viruses from the human gut microbiome

Bacteriophages have important roles in the ecology of the human gut microbiome but are under-represented in reference databases. To address this problem, we assembled the Metagenomic Gut Virus catalogue that comprises 189,680 viral genomes from 11,810 publicly available human stool metagenomes. Over 75% of genomes represent double-stranded DNA phages that infect members of the Bacteroidia and Clostridia classes. Based on sequence clustering we identified 54,118 candidate viral species, 92% of which were not found in existing databases. The Metagenomic Gut Virus catalogue improves detection of viruses in stool metagenomes and accounts for nearly 40% of CRISPR spacers found in human gut Bacteria and Archaea. We also produced a catalogue of 459,375 viral protein clusters to explore the functional potential of the gut virome. This revealed tens of thousands of diversity-generating retroelements, which use error-prone reverse transcription to mutate target genes and may be involved in the molecular arms race between phages and their bacterial hosts.

59 BASIC BIOLOGICAL SCIENCES↗

A unified catalog of 204,938 reference genomes from the human gut microbiome

Comprehensive, high-quality reference genomes are required for functional characterization and taxonomic assignment of the human gut microbiota. We present the Unified Human Gastrointestinal Genome (UHGG) collection, comprising 204,938 nonredundant genomes from 4,644 gut prokaryotes. These genomes encode >170 million protein sequences, which we collated in the Unified Human Gastrointestinal Protein (UHGP) catalog. The UHGP more than doubles the number of gut proteins in comparison to those present in the Integrated Gene Catalog. More than 70% of the UHGG species lack cultured representatives, and 40% of the UHGP lack functional annotations. Intraspecies genomic variation analyses revealed a large reservoir of accessory genes and single-nucleotide variants, many of which are specific to individual human populations. The UHGG and UHGP collections will enable studies linking genotypes to phenotypes in the human gut microbiome.

59 BASIC BIOLOGICAL SCIENCES↗

COVID-19 pandemic reveals the peril of ignoring metadata standards

Efficient response to the pandemic through the mobilization of the larger scientific community is challenged by the limited reusability of the available primary genomic data. Here, the Genomic Standards Consortium board highlights the essential need for contextual genomic data FAIRness, for empowering key data-driven biological questions.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗

Roadmap for naming uncultivated Archaea and Bacteria

The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as ‘type material’, thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity.

59 BASIC BIOLOGICAL SCIENCES↗