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The contrasting roles of nitric oxide drive microbial community organization as a function of oxygen presence.

ABSTRACT: Microbial assemblages are omnipresent in the biosphere, forming communities on the surfaces of roots and rocks and within living tissues. These communities can exhibit strikingly beautiful compositional structures, with certain members reproducibly occupying particular spatiotemporal microniches. Despite this reproducibility, we lack the ability to explain these spatial patterns. We hypothesize that certain spatial patterns in microbial communities may be explained by the exchange of redox-active metabolites whose biological function is sensitive to microenvironmental gradients. To test this, we developed a simple community consisting of synthetic Pseudomonas aeruginosa strains with a partitioned denitrification pathway: a strict consumer and strict producer of nitric oxide (NO), a key pathway intermediate. Because NO can be both toxic or beneficial depending on the amount of oxygen present, this system provided an opportunity to investigate whether dynamic oxygen gradients can tune metabolic cross-feeding and fitness outcomes in a predictable fashion. Using a combination of genetic analysis, controlled growth environments, and imaging, we show that oxygen availability dictates whether NO cross-feeding is deleterious or mutually beneficial and that this organizing principle maps to the microscale. More generally, this work underscores the importance of considering the double-edged and microenvironmentally tuned roles redox-active metabolites can play in shaping microbial communities.

SUBMITTER: Wilbert SA

PROVIDER: S-EPMC9772256 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature

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The contrasting roles of nitric oxide drive microbial community organization as a function of oxygen presence.

Wilbert Steven A SA Newman Dianne K DK

Current biology : CB 20221027 24

Microbial assemblages are omnipresent in the biosphere, forming communities on the surfaces of roots and rocks and within living tissues. These communities can exhibit strikingly beautiful compositional structures, with certain members reproducibly occupying particular spatiotemporal microniches. Despite this reproducibility, we lack the ability to explain these spatial patterns. We hypothesize that certain spatial patterns in microbial communities may be explained by the exchange of redox-activ ...[more]

PMID: 36306787

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The contrasting roles of nitric oxide drive microbial community organization as a function of oxygen presence.

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The contrasting roles of nitric oxide drive microbial community organization as a function of oxygen presence.

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