D. Speth

Branched-chain amino acid assimilation enables mixotrophy of ammonia-oxidizing archaeal sponge symbionts

Marine sponges and ammonia-oxidizing archaea (AOA) represent one of the earliest animal-microbe symbioses. AOA are considered metabolically constrained chemolithoautotrophs that remove nitrogenous waste within the sponge holobiont. Here, we expand this view by demonstrating that symbiotic AOA assimilate branched-chain...

A streamlined and abundant Nitrosopumilus population retains vitamin biosynthesis under high purifying selection in the Baltic Sea

Genome streamlining is expected to favor the loss of costly biosynthetic functions, raising the question of what benefit justifies the continued maintenance of complex pathways in small genomes. Here, we investigated this question in an abundant Nitrosopumilus population from the Baltic Sea that combined a streamlined...

Activity and diversity of sulfate- and methane-based pathways of anaerobic chitin and N-acetylglucosamine degradation in marine sediments

ABSTRACT Sulfate reduction is estimated to account for half of the organic carbon respiration in anoxic, organic-rich ocean sediments. Sulfate-reducing microorganisms (SRMs) typically oxidize simple carbon compounds, such as primary alcohols, or small fatty acids. However, much of the organic input to the seafloor is c...

A Saccharimonadia epibiont interacts with the polyphosphate-accumulating bacterium Candidatus Phosphoribacter in wastewater treatment plants