Soil H₂ oxidizing bacteria metabolize H₂ from the atmosphere, but soil carbon substrates and environmental factors influence their distribution in the soil profile. We conducted a field survey of the spatial distribution of H₂ content and high-affinity H₂ oxidation activity in the soil profile (5 cm, 15 cm, and 35 cm) and between the soybean rhizosphere and bulk soil. We found the H₂ content declined exponentially with soil depth, but potential H₂ oxidation activity was consistent at all soil depths. The rhizosphere soil had 66% more high-affinity H₂ oxidation activity than bulk soil. Simultaneous presence of H₂ and carbon likely facilitates mixotrophic growth of H₂ oxidizing bacteria in the rhizosphere.

中文翻译：

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农业土壤剖面中高亲和力 H2 氧化活性的空间异质性


土壤 H ₂ 氧化细菌从大气中代谢 H ₂ ，但土壤碳基质和环境因素会影响它们在土壤剖面中的分布。我们对土壤剖面（5 cm、15 cm 和 35 cm）以及大豆根际和块状土壤之间 H ₂ 含量和高亲和力 H ₂ 氧化活性的空间分布进行了实地调查。我们发现 H ₂ 含量随土壤深度呈指数下降，但潜在的 H ₂ 氧化活性在所有土壤深度都是一致的。根际土壤的高亲和力 H₂ 氧化活性比块状土壤高 66%。H ₂ 和碳同时存在可能促进 H ₂ 氧化细菌在根际的混合营养生长。