Here the authors leverage a crossfeeding, engineered microbial community to demonstrate that strain abundance cycles are robust across environmental conditions. They pair this with a nonlinear dynamic model to elucidate population cycles.

This structure of an archaeal tailed virus (arTV) provides detailed insights into arTV assembly and infection mechanisms.

Microbial communities, exposed to early Earth-like conditions in a modern microbialite reef, change cyclically due to seasonal environmental variations, implying evolved metabolic processes in microbialites over time, based on multiple chemical, physical, and biological analyses.

Corrinoid-dependent enzymes either catalyze methyltransfer reactions, or they generate substrate radicals using adenosylcobalamin for subsequent rearrangement reactions. The corrinoid-dependent methyltransferases are present in all domains of life and assumed to be exclusive for methyl-groups. In Methanosarcina, however, trace ethane production from ethanol has been shown in vivo, which led to the hypothesis that corrinoid-dependent methanol-specific methyltransferases are promiscuous towards also accepting ethyl-groups. Here, we show that the conversion of ethanol to trace amounts of ethane in Methanosarcina acetivorans involves homologous reactions of the known methanol-to-methane metabolism. The methanol methyltransferase (MtaB) activates ethanol and loads the ethyl-group onto the corrinoid-containing methyl-accepting protein (MtaC). Besides MtaCB, substrate promiscuity in corrinoid:coenzyme M methyltransferase (MtaA) and methyl-coenzyme M reductase (Mcr) are required to grant the microbe the capacity for ethane production. We show that the MtaCB subunits of M. acetivorans can activate ethanol, however, the ethane yields compared to methane are ca. 3 orders of magnitude lower. The ethyl-transfer capability was confirmed for each of the three MtaCB isozyme by quantifying the amount of ethane produced by mtaCB double deletion strains during growth in ethanol-supplemented media and in resting-cell suspensions. Ethane formation requires the cells to be grown on methanol to trigger the expression of the mtaCB genes, and detectable ethane formation starts only after all methanol has been consumed. Demonstrating that corrinoid-dependent methanol-specific methyltransferases process ethyl groups extends the pool of reactions to be considered in metabolic networks and suggests possible routes for biogenic ethane in nature.

The nitrogen-fixing and nodule-forming symbionts of legumes, which belong to the class Betaproteobacteria, are informally known as beta-rhizobia. Thus…

The rapid evolution of microbiology as a field of research has led to the introduction of new terminology and the adaptation of existing terms. However, inconsistencies in the use of these terms, inc...

Anaerobic digestion (AD) is an effective approach for the resource and energy recovery of straw biomass. However, the process faces challenges such as…

Abstract. Metatranscriptome sequencing dramatically expanded the known diversity of the global RNA virome and, in particular, suggested several new candida

Nitrite-oxidizing bacteria (NOB) are integral to the global nitrogen cycle, yet their adaptations to acidic environments remain poorly understood. This study introduces Candidatus Nitrospira acidotole...

The anaerobic ammonium oxidation (anammox) process is an economical and efficient technology for treating high-nitrogen wastewater. Nonetheless, eleva…

Corrinoid-dependent enzymes either catalyze methyltransfer reactions, or they generate substrate radicals using adenosylcobalamin for subsequent rearrangement reactions. The corrinoid-dependent methyl...

Lipoproteins are major cell-surface components in archaea, but their functions and the lipidation mechanisms are unclear. Here, Hong et al. identify two proteins required for attachment of proteins to unique archaeal membrane lipids via thioether bonds, and demonstrate their importance in archaeal physiology.