• 关键词：厌氧氨氧化菌  全细菌  旱地深层土壤  加水实验  群落结构

• 基金项目：国家自然科学基金（No.41322012，41671471）；中国科学院青年创新促进会资助项目；中国科学院战略性先导科技专项（No.XDB15020303）

• 王成
• 1. 中国科学院生态环境研究中心, 北京 100085;2. 中国科学院大学, 北京 100049

• 庄林杰
• 中国科学院生态环境研究中心, 北京 100085

• 赵思研
• 1. 中国科学院生态环境研究中心, 北京 100085;2. 中国科学院大学, 北京 100049

• 祝贵兵
• 中国科学院生态环境研究中心, 北京 100085

• 摘要：为研究旱地深层土壤中厌氧氨氧化菌及相伴随的全细菌的群落结构对水分增加的响应变化，选取西澳大陆Kalgoorlie地区60 m深的典型旱地土壤，采集淀积层和母质层土壤样品，加入纯水或3.5%的盐水进行密闭培养.针对厌氧氨氧化功能基因hzsB基因及细菌16S rRNA基因进行高通量测序.结果显示：初始土壤并未有厌氧氨氧化菌的检出，加水培养3个月之后，开始有厌氧氨氧化菌的检出，此时盐水培养中厌氧氨氧化菌群多样性要高于纯水培养的结果.且纯水培养中，厌氧氨氧化菌群落结构在淀积层和母质层中类似，均以Candidatus ‘Brocadia anammoxidans’为主（92.09%和91.94%），另有一定量的Candidatus ‘Jettenia sp.’（7.43%和7.89%）.盐水培养中，淀积层主导种属为Candidatus ‘Brocadia anammoxidans’（50.03%）和Candidatus ‘Jettenia sp.’（40.25%），母质层主导种属为Candidatus ‘Jettenia sp.’（71.20%）；继续培养一个月后，盐水培养和纯水培养中厌氧氨氧化菌群多样性均有增加，且盐水培养中厌氧氨氧化菌群多样性依旧要高于纯水培养的结果.此时纯水培养中，淀积层依旧以Candidatus ‘Brocadia anammoxidans’（87.88%）为主导，母质层中Candidatus ‘Jettenia sp.’增长明显，达到50.90%，取代Candidatus ‘Brocadia anammoxidans’（39.92%）成为主导种属.盐水培养中，Candidatus ‘Brocadia fulgida’（45.19%）与Candidatus ‘Brocadia anammoxidans’（47.99%）共同主导淀积层厌氧氨氧化菌群，母质层中Candidatus ‘Brocadia fulgida’增至73.14%，取代Candidatus ‘Jettenia sp.’（13.65%）成为主导种属.另外，相伴随的母质层土壤全细菌群落结构在培养过程中相对比较稳定，以厌氧或兼性厌氧的变形菌门（Proteobacteria）占绝对主导（81.84%~95.45%），其中大部分为海洋营生的盐单胞菌科（Halomonadaceae）和希瓦氏菌科（Shewanellaceae）.同时厚壁菌门（Firmicutes）在培养过程中出现较明显增长.培养过程中，Candidatus ‘Jettenia sp.’与放线菌门（Actinobacteria）的相对丰度变化显著正相关（r=0.991，p=0.009），与海洋营生的希瓦氏菌科（Shewanellaceae）的相对丰度变化显著负相关（r=-0.971，p=0.029）.综上，本文在一定程度上揭示了水分及盐度的变化对厌氧氨氧化的发生及菌群组成分布的重要影响，进一步拓展了对不同生境中厌氧氨氧化菌生理特性的认识.

• Abstract：To study the response of anammox bacterial and other bacterial community changes in dryland deep soils to water increase, soil samples at illuvium and parent material layers were collected from the typical dryland soil at 60 m depth in Kalgoorlie, Western Australia, and incubated with freshwater or salty water (3.5%). The higH-throughput sequencing aimed at the hydrazine synthase β-subnit gene (hzsB) of anammox bacteria and 16S rRNA gene of total bacteria were performed. The results showed that no anammox bacteria was detected in original soils. After three months of incubation, anammox bacteria began to be detected, and their diversity were higher in salty water than that in freshwater. In freshwater, the illuvium and parent material soil layers had similar anammox bacterial community compositions, which were dominated by Candidatus ‘Brocadia anammoxidans’ (92.09% and 91.94%). In salty water, the illuvium soil layer was dominated by Candidatus ‘Brocadia anammoxidans’ (50.03%) and Candidatus ‘Jettenia sp.’ (40.25%), while the parent material soil layer was dominated by Candidatus ‘Jettenia sp.’ (71.20%); After four months of incubation, the anammox bacterial diversity increased in both freshwater and salty water, and they were still higher in salty water than that in freshwater. In freshwater, the illuvium soil layer was still dominated by Candidatus ‘Brocadia anammoxidans’ (87.88%), while the parent material soil layer was dominated by Candidatus ‘Jettenia sp.’ (50.90%) instead of Candidatus ‘Brocadia anammoxidans’ (39.92%). In salty water, the illuvium soil layer was dominated by both Candidatus ‘Brocadia fulgida’ (45.19%) and Candidatus ‘Brocadia anammoxidans’ (47.99%), while Candidatus ‘Brocadia fulgida’ (73.14%) rather than Candidatus ‘Jettenia sp.’ (13.65%) dominated in the parent material soil layer. The total bacterial community compositions kept relatively stable during the incubation, it was dominated by Proteobacteria (81.84%~95.45%), among which the majority part were typical marine bacterial family Halomonadaceae and Shewanellaceae. Meanwhile, the relative abundance of Firmicutes showed some increase during the incubation. There existed significantly positive relations between the relative abundance of Candidatus ‘Jettenia sp.’ and Actinobacteria (r=0.991, p=0.009), and significantly negative relations between the relative abundance of Candidatus ‘Jettenia sp.’ and Shewanellaceae (r=-0.971, p=0.029). In conclusion, this study revealed the effects of water added incubation on the occurrence of anammox and their bacterial community compositions, further expanded the understanding of anammox bacterial physiological characteristics in different habitats.

• Key words：anammox bacteria  total bacteria  dryland deep soil  water added incubation  community compositions

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