About this Research Topic
As documented in the Research Topic “The Atmospheric Microbiota”, the outdoor atmosphere up to high altitude is a biotic environment. Despite harsh conditions, it hosts a rich microbiota that interacts with the physical and chemical components of its environment. A wide variety of microorganisms with different metabolic capacities have been reported, including heterotrophs, phototrophs, methylotrophs and many others, as well as numerous biochemical products potentially emitted by microbial cells while airborne. Beside microbes, the microbes, the atmospheric environment is composed of thousands of organic and inorganic molecules: organic acids, sugars, lipids, proteins, etc. Some of these compounds directly relate with (i) the presence and diversity of microorganisms, such as DNA and other cellular components; (ii) a possible metabolic activity in the atmospheric environment, such as RNA, proteins, exudates or secondary metabolites; (iii) chemicals targets of biological processes, such as nutrients, substrates to enzymes, effectors and co-factors of enzymes and biological functions, scavengers etc. However, the low density of biomass in the atmosphere often challenges microbiological investigations, in particular regarding functional aspects. We thus still have very poor knowledge of the microbiological mechanisms occurring in the atmosphere, their extent and environmental impacts.
This Research Topic “The Atmospheric Microbiota II” is intended to provide new insights about the contribution of microbial cells to the chemical composition of the atmosphere. If microbiologically-mediated processes indeed occur in the atmosphere, they modify the chemical environment, thus producing chemical signatures of these processes, e.g. biomarkers or bioproducts that reflect the in situ functioning of microorganisms, and attest of its extent and impact. These include, but are not limited to, the presence of more or less specific biochemical products (metabolites, proteins, transcripts, etc), nutrients/substrates (organics, sugars, oxidants, etc), effectors/cofactors (ATP, metals, etc) and others characteristics such as enzymatic activity, isotope ratios modifications, etc.
We are pleased to welcome contributions documenting microbial activity in the different compartments of the atmosphere (aerosols, clouds, precipitation). This topic includes the development of methods, field studies, laboratory and simulation chamber experimentations, experimental design, and other informative study that can help elucidating the functioning of microorganisms in the atmosphere, its consequences and environmental impacts at small to global scale. Reports associating biodiversity with chemical aspects, and presented in this frame, will be considered as well.
Keywords: Atmosphere, biodiversity, biomarkers, metabolism, microbial activity
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.