Diverse members of Bradyrhizobium diazoefficiens, B. japonicum, and B. ottawaense were isolated from the roots of field-grown sorghum plants in Fukushima, and classified into “Rhizobia” with nodulated soybeans, “Free-living diazotrophs”, and “Non-diazotrophs” by nitrogen fixation and nodulation assays. Genome analyses revealed that B. ottawaense members possessed genes for N2O reduction, but lacked those for the Type VI secretion system (T6SS). T6SS is a new bacterial weapon against microbial competitors. Since T6SS-possessing B. diazoefficiens and B. japonicum have mainly been isolated from soybean nodules in Japan, T6SS-lacking B. ottawaense members may be a cryptic lineage of soybean bradyrhizobia in Japan.

中文翻译：

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非豆科高粱植物中慢生根瘤菌的多样性：B. ottawaense分离出 N ₂ O 还原酶基因独特且缺乏 VI 型分泌系统

Bradyrhizobium diazoefficiens、B. japonicum 和 B. ottawaense 的不同成员是从福岛田间种植的高粱植物的根中分离出来的，并将其分为具有结瘤大豆的“根瘤菌”、“自由生活的固氮菌”和“非固氮菌” ”通过固氮和结瘤试验。基因组分析显示 B. ottawaense 成员拥有减少 N2O 的基因，但缺乏 VI 型分泌系统 (T6SS) 的基因。T6SS是对抗微生物竞争者的新型细菌武器。由于拥有 T6SS 的 B. diazoefficiens 和 B. japonicum 主要是从日本的大豆根瘤中分离出来的，因此缺乏 T6SS 的 B. ottawaense 成员可能是日本大豆慢根瘤菌的一个隐秘谱系。