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Author Spotlight: Unraveling the Mysteries of Terrestrial Anaerobic Microorganisms in Uncharted Environments by In Situ Culturing
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Diazotrophic Anaeromyxobacter Isolates from Soils.
Yoko Masuda1, Haruka Yamanaka1, Zhen-Xing Xu1
1Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Applied and Environmental Microbiology
|June 14, 2020
Summary
This study confirms that Anaeromyxobacter bacteria can fix nitrogen, a vital process for soil ecosystems. Researchers provided experimental evidence of nitrogen fixation in Anaeromyxobacter, highlighting its environmental importance.
Area of Science:
- Microbiology
- Environmental Science
- Biochemistry
Background:
- Biological nitrogen fixation is crucial for terrestrial ecosystems.
- Previous studies suggested Anaeromyxobacter's role in nitrogen fixation based on gene detection, but lacked experimental proof.
- The genetic basis and nitrogen-fixing capability of Anaeromyxobacter remained unverified.
Purpose of the Study:
- To experimentally verify the diazotrophic (nitrogen-fixing) ability of Anaeromyxobacter.
- To investigate the genetic background and functional capacity for nitrogen fixation in Anaeromyxobacter strains.
- To demonstrate nitrogen fixation by Anaeromyxobacter in both laboratory and soil environments.
Main Methods:
- Genomic analysis of nitrogenase (nif) gene clusters in Anaeromyxobacter strains.
- Culture-dependent experiments using isolated Anaeromyxobacter strains (PSR-1 and Red267).
- Acetylene Reduction Activity (ARA) assays and N2-dependent growth studies in vitro and in soil.
Main Results:
- Anaeromyxobacter strains PSR-1 and Red267 possess the essential nif genes for nitrogenase.
- Both strains exhibited N2-dependent growth and acetylene reduction activity in vitro.
- Inoculated soil samples showed nitrogenase activity, confirming Anaeromyxobacter's nitrogen fixation in situ.
Conclusions:
- Anaeromyxobacter species are confirmed diazotrophs with the genetic machinery for nitrogen fixation.
- Nitrogen fixation is an important survival strategy for Anaeromyxobacter in nitrogen-limited environments.
- This study establishes Anaeromyxobacter as a significant contributor to nitrogen cycling in soil ecosystems.
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