Glycan Annotation of Mass Spectrometry Data.

Carbohydrates are fundamental molecules of life that are involved in virtually all biological processes. The chemical diversity of glycans─carbohydrate chains─enables diverse functions but also challenges analytics. Annotation of glycans in mass spectrometry (MS) data relies heavily on experimental databases or manual calculations, hindering the discovery of novel glycan compositions and structures.

Acidimicrobiia, the actinomycetota of coastal marine sediments: Abundance, taxonomy and genomic potential.

Microbial communities in marine sediments represent some of the densest and most diverse biological communities known, with up to a billion cells and thousands of species per milliliter. Among this taxonomic diversity, the class Acidimicrobiia, within the phylum Actinomycetota, stands out for its consistent presence, yet its limited taxonomic understanding obscures its ecological role. We used metagenome-assembled genomes from a 5-year Arctic fjord sampling campaign and compared them to publicly available Acidimicrobiia genomes using 16S rRNA gene and whole-genome phylogenies, alongside gene prediction and annotation to study their taxonomy and genomic potential.

Distinct actors drive different mechanisms of biopolymer processing in polar marine coastal sediments.

Heterotrophic bacteria in the ocean initiate biopolymer degradation using extracellular enzymes that yield low molecular weight hydrolysis products in the environment, or by using a selfish uptake mechanism that retains the hydrolysate for the enzyme-producing cell. The mechanism used affects the availability of hydrolysis products to other bacteria, and thus also potentially the composition and activity of the community. In marine systems, these two mechanisms of substrate processing have been studied in the water column, but to date, have not been investigated in sediments.