The Trichodesmium genus comprises some of the most abundant N2-fixing organisms in oligotrophic marine ecosystems. Since nitrogenase, key enzyme for N2 fixation, is irreversibly inhibited upon O2 exposure, these have to coordinate their ability with simultaneous photosynthetic production. Although being principal object many laboratory and field studies, overall process how reconciles two mutua...

Trichodesmium is the dominant photoautotrophic dinitrogen (N2) fixer (diazotroph) in ocean. Iron an important factor limiting growth of marine diazotrophs including mainly because high iron content its N2-fixing enzyme, nitrogenase. However, it still lacks a quantitative understanding how dynamic allocation among physiological processes acts to regulate and N2 fixation Trichodesmium. Here, we c...

Growing slowly, marine N2 fixers are generally expected to be competitive only where nitrogen (N) supply is low relative to that of phosphorus (P) with respect to the cellular N:P ratio (R) of nonfixing phytoplankton. This is at odds with observed high N2 fixation rates in the oligotrophic North Atlantic where the ratio of nutrients supplied to the surface is elevated in N relative to the avera...

Nitrogen fixation is an important and challenging transformation in chemistry. It currently achieved by the Haber–Bosch process that reduces N2 to NH3 on large scale but at cost of a huge environmental footprint. In search for greener processes, electrochemically driven reduction might become sustainable answer. The development molecular homogeneous catalysis has gained momentum over last decad...

Populations of genetically identical microorganisms residing in the same environment can display marked variability in their phenotypic traits; this phenomenon is termed phenotypic heterogeneity. The relevance of such heterogeneity in natural habitats is unknown, because phenotypic characterization of a sufficient number of single cells of the same species in complex microbial communities is te...

We analyzed a metagenome of the bacterial community associated with the taproot of sugar beet (Beta vulgaris L.) in order to investigate the genes involved in plant growth-promoting traits (PGPTs), namely 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, indole acetic acid (IAA), N2 fixation, phosphate solubilization, pyrroloquinoline quinone, siderophores, and plant disease suppression as...

Mutants of Azotobacter vinelandii affected in N2 fixation in the presence of 1 microM Na2MoO4 (conventional system), 50 nM V2O5, or under Mo deficiency (alternative system) have been isolated after Tn5 mutagenesis with the suicide plasmid pSUP1011. These mutants can be grouped into at least four broad phenotypic classes. Mutants in the first class are Nif- under Mo sufficiency but Nif+ under Mo...