About this Research Topic
A predictive, mechanistic understanding of the controls on microbial element cycling remains a grand challenge in microbiology. The composition and concentration of carbon sources, electron donors and electron acceptors influence microbial community structure by selecting for microbial sub-populations with distinct catabolic and respiratory pathways. Selective inhibitors and trace nutrient availability modulate the activity of metabolic enzymes and thus influence the distribution of microbial sub-populations with distinct metabolic and respiratory traits. Thus, complex multi-dimensional environmental gradients influence the composition, gene content and element cycling activity of microbiomes. While some parameters are known to select for different respiratory activities (e.g. lanthanides as essential nutrients for methanotrophs, molybdate as a specific inhibitor of sulfate reduction, carbon:nitrogen ratio as a control on the end-products of nitrate respiration), there are others to discover, and demonstrating how selective parameters operate and mediate element cycling across scales requires multi-disciplinary research in both the lab and field.
In this Research Topic, we invite articles on the biochemistry, physiology and ecology of microbial respiratory metabolisms in laboratory and field contexts with a focus on defining the parameters that selectively influence the activity of microbial element cycling. We particularly encourage cross-cutting mechanistic ecology research that improves our multi-scale understanding of the selective controls on microbial respiration. For example, we welcome studies relating microbial metabolic models to element cycling in the field, connecting thermodynamic constraints to the evolution of metabolic pathways, identifying new metabolic inhibitors or trace nutrient dependencies, or defining the mode of action of selective nutrients or inhibitors.
In particular, we welcome Original Research and Review papers focusing on the following themes:
• Defining the niche space of microbial energy metabolisms in the environment.
• Identifying selective nutrients and inhibitors of microbial energy metabolisms.
• Linking thermodynamic predictions to metabolic models and microbial preferences.
• Understanding the evolution and origin of microbial respiratory metabolisms.
• Defining interactions between trophic levels and their influence on respiratory activity.
• Cross-feeding of electron donors and electron acceptors and their role in community stability and assembly.
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.