Scholarlink

<p>Benthic biofilms, the aggregates of multi-trophic microorganisms, play an important role in nitrogen cycling in aquatic ecosystems and are significantly influenced by flow velocity. Nevertheless, the roles of multi-trophic microbial communities in nitrogen cycling of benthic biofilms remain unclear, especially under flow velocity conditions. In this study, we investigated how low trophic level microbial communities (bacteria, fungi, and algae), primary predator (protozoa) and secondary predator (metazoan) mediate the nitrogen cycling in benthic biofilms under low (0.05 m/s) moderate (0.1 m/s) and high (0.15 m/s) flow velocity conditions. The results showed that the activities of ammonia monooxygenase, nitrate reductase and nitrite reductase in benthic biofilms under high flow velocity increased 26.32%, 18.66%, and 10.46%, respectively, compared with those under low flow velocity. Metagenomic sequencing analysis indicated that high flow velocity enhanced the relative abundances of functional genes involved in nitrification (<i>amoABC</i>) and denitrification (<i>narG</i>, <i>nirK</i>, and <i>nirS</i>). Compared with other trophic level microorganisms, the bacterial richness had the highest explanation (42.36%) for the variation in ammonia monooxygenase, and the variations in activities of nitrate reductase and nitrite reductase were explained 33.29% and 36.68% by protozoan richness, respectively. High richness index might promote nitrification and denitrification process via upregulating amino acid transport and metabolism, and signal transduction mechanisms. The negative cross trophic associations (potential predation activity) enhanced nitrification and denitrification by promoting microbial activity further enhancing ATPase activity and potential electron donor production. This study provides a new understanding of how multi-trophic microorganisms regulate the nitrogen cycling in benthic biofilms under increased flow velocity, which will benefit river management.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Increasing flow velocity promotes nitrification and denitrification in benthic biofilms via enhancing the diversity and potential predation behavior among multi-trophic microorganisms

  • 期刊论文

  • 发表日期：

    2025年7月17日

查看全文
  • Bo Zhang,
  • Juan Chen,
  • Chao Wang,
  • Peifang Wang,
  • Ge Cui,
  • Han Gao,
  • Bingbing Feng,
  • Sheng Sheng,
  • Jingjing Fu

摘要

Benthic biofilms, the aggregates of multi-trophic microorganisms, play an important role in nitrogen cycling in aquatic ecosystems and are significantly influenced by flow velocity. Nevertheless, the roles of multi-trophic microbial communities in nitrogen cycling of benthic biofilms remain unclear, especially under flow velocity conditions. In this study, we investigated how low trophic level microbial communities (bacteria, fungi, and algae), primary predator (protozoa) and secondary predator (metazoan) mediate the nitrogen cycling in benthic biofilms under low (0.05 m/s) moderate (0.1 m/s) and high (0.15 m/s) flow velocity conditions. The results showed that the activities of ammonia monooxygenase, nitrate reductase and nitrite reductase in benthic biofilms under high flow velocity increased 26.32%, 18.66%, and 10.46%, respectively, compared with those under low flow velocity. Metagenomic sequencing analysis indicated that high flow velocity enhanced the relative abundances of functional genes involved in nitrification (amoABC) and denitrification (narG, nirK, and nirS). Compared with other trophic level microorganisms, the bacterial richness had the highest explanation (42.36%) for the variation in ammonia monooxygenase, and the variations in activities of nitrate reductase and nitrite reductase were explained 33.29% and 36.68% by protozoan richness, respectively. High richness index might promote nitrification and denitrification process via upregulating amino acid transport and metabolism, and signal transduction mechanisms. The negative cross trophic associations (potential predation activity) enhanced nitrification and denitrification by promoting microbial activity further enhancing ATPase activity and potential electron donor production. This study provides a new understanding of how multi-trophic microorganisms regulate the nitrogen cycling in benthic biofilms under increased flow velocity, which will benefit river management.