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Updated: Jun 5, 2026

Generation of Marked and Markerless Mutants in Model Cyanobacterial Species

Generation of Marked and Markerless Mutants in Model Cyanobacterial Species

Published on: May 29, 2016

Nitrogen fixation by marine cyanobacteria.

Jonathan P Zehr¹

¹Department of Ocean Sciences, University of California, Santa Cruz, CA 95064, USA. zehrj@ucsc.edu

Trends in Microbiology

|January 14, 2011

Summary

Researchers are identifying novel nitrogen-fixing cyanobacteria in oceans. These unicellular organisms possess unique traits and play a crucial role in the marine nitrogen cycle, impacting global nutrient budgets.

Area of Science:

Marine Microbiology
Biogeochemistry
Cyanobacterial Ecology

Background:

Oceanic nitrogen (N) budgets show discrepancies between nitrogen fixation and denitrification rates.
Research is actively identifying nitrogen (N2)-fixing cyanobacteria and quantifying their contribution to marine N cycles.

Purpose of the Study:

To investigate previously unrecognized unicellular cyanobacteria, including cultivated and uncultivated types.
To understand the metabolic and genomic properties of these organisms and their distribution.

Main Methods:

Genomic analysis of oceanic N2-fixing cyanobacteria.
Investigating metabolic pathways and physiological constraints.
Ecological distribution studies.

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Main Results:

Discovery of widely distributed, unicellular N2-fixing cyanobacteria with unusual properties.
Uncultivated unicellular N2-fixing cyanobacteria (UCYN-A) lack key metabolic pathways like the TCA cycle and photosystem II.
Oceanic N2-fixing cyanobacteria genomes are conserved, with diversity maintained by rearrangements.

Conclusions:

Unicellular cyanobacteria represent a significant, yet previously underestimated, component of oceanic nitrogen fixation.
Varied physiological and ecological constraints influence the distribution of major cyanobacterial groups.
These findings have critical implications for understanding and modeling the marine nitrogen cycle budget.