Chemotaxis may assist marine heterotrophic bacterial diazotrophs to find microzones suitable for N₂ fixation in the pelagic ocean.

ABSTRACT: Heterotrophic bacterial diazotrophs (HBDs) are ubiquitous in the pelagic ocean, where they have been predicted to carry out the anaerobic process of nitrogen fixation within low-oxygen microenvironments associated with marine pelagic particles. However, the mechanisms enabling particle colonization by HBDs are unknown. We hypothesized that HBDs use chemotaxis to locate and colonize suitable microenvironments, and showed that a cultivated marine HBD is chemotactic toward amino acids and phytoplankton-derived DOM. Using an in situ chemotaxis assay, we also discovered that diverse HBDs at a coastal site are motile and chemotactic toward DOM from various phytoplankton taxa and, indeed, that the proportion of diazotrophs was up to seven times higher among the motile fraction of the bacterial co

SUBMITTER: Hallstrom S 

PROVIDER: S-EPMC9561647 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature