free-living nitrogen fixing bacteria

例句：

1. 1.These free-living nitrogen fixing bacteria play a crucial role in the nitrogen cycle.
   这些自由生活的固氮细菌在氮循环中起着至关重要的作用。
2. 2. The research on free-living nitrogen fixing bacteria has significant implications for agricultural productivity.
   对自由生活的固氮细菌的研究对农业生产力有重大影响。
3. 3.The bacteria are capable of fixing nitrogen from the atmosphere, which can help to mitigate the effects of climate change.
   这些细菌能够从大气中固定氮，这有助于减轻气候变化的影响。