Diazotrophic <i>Anaeromyxobacter</i> Isolates from Soils
Yoko Masuda, Haruka Yamanaka, Zhenxing Xu, Yutaka Shiratori, Toshihiro Aono, Seigo Amachi, Keishi Senoo, Hideomi Itoh
Abstract
Anaeromyxobacter is globally distributed in soil environments, especially predominant in paddy soils. Current studies based on environmental DNA/RNA analyses frequently detect gene fragments encoding nitrogenase of Anaeromyxobacter from various soil environments. Although the importance of Anaeromyxobacter as a diazotroph in nature has been suggested by culture-independent studies, there has been no solid evidence and validation from genomic and culture-based analyses that Anaeromyxobacter fixes nitrogen. This study demonstrates that Anaeromyxobacter harboring nitrogenase genes exhibits diazotrophic ability; moreover, N 2 -dependent growth was demonstrated in vitro and in the soil environment. Our findings indicate that nitrogen fixation is important for Anaeromyxobacter to survive under nitrogen-deficient environments and provide a novel insight into the environmental function of Anaeromyxobacter , which is a common bacterium in soils.