Tang Peng, Li Jun, Zhang Jing, Zhu Yuhan, Zheng Zhaoming, Zhang Xin, Gao Peng, Liu Tao, Guo Jianhua
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
Water Res. 2025 Jan 1;268(Pt A):122617. doi: 10.1016/j.watres.2024.122617. Epub 2024 Oct 11.
Complete ammonia oxidation (comammox) bacteria have been detected in full-scale wastewater treatment plants. However, the slow growth rate limits the research and applications of comammox. Quorum sensing (QS) is an intercellular communication process to regulate microbial physiological metabolism, but its role in comammox Nitrospira has rarely been reported. In this study, denitrifying filter backwash, return and anoxic tank sludges were utilized as seeding inoculums to enrich comammox bacteria, with the addition of three types of signaling molecules (C6-HSL, C8-HSL and C12-HSL). Under ammonia- and dissolved oxygen (DO)-limited conditions, 12 lab-scale sequencing batch reactors (SBRs) were operated for 90 days. Quantitative polymerase chain reaction (qPCR) and 16S rRNA gene sequencing supported the enrichment of comammox Nitrospira in all SBRs. The highest absolute abundance of comammox Nitrospira amoA gene was detected in the anoxic tank sludge with exogenously added C8-HSL, reaching an average of 2.34×10 copies/(g sludge). In this condition, comammox Nitrospira and ammonia-oxidizing archaea contributed up to 94 % of the total nitrification activity, with ammonia-oxidizing bacteria accounting for only 6 %. Overall, the role of QS in comammox Nitrospira enrichment was confirmed, with signaling molecules significantly accelerating the growth of comammox Nitrospira, promoting functional enzyme activity, and strengthening nitrifying bacterial competitiveness. Among the signaling molecules tested, C8-HSL exhibited the most pronounced promotional effect, followed by C6-HSL and C12-HSL. Using anoxic tank sludge as the seed sludge with the addition of C8-HSL provides a rapid and reliable enrichment strategy for comammox Nitrospira. These findings offer insights into the role of QS in comammox bacteria enrichment, and might facilitate the development of biotechnologies for wastewater treatment based on comammox Nitrospira.
在全尺寸污水处理厂中已检测到全程氨氧化（comammox）细菌。然而，其缓慢的生长速度限制了对comammox的研究和应用。群体感应（QS）是一种调节微生物生理代谢的细胞间通讯过程，但其在comammox硝化螺旋菌中的作用鲜有报道。在本研究中，以反硝化滤池反冲洗污泥、回流污泥和缺氧池污泥作为接种物来富集comammox细菌，并添加了三种信号分子（C6-HSL、C8-HSL和C12-HSL）。在氨和溶解氧（DO）受限的条件下，运行了12个实验室规模的序批式反应器（SBR），为期90天。定量聚合酶链反应（qPCR）和16S rRNA基因测序证实了所有SBR中comammox硝化螺旋菌均得到了富集。在外源添加C8-HSL的缺氧池污泥中检测到comammox硝化螺旋菌amoA基因的绝对丰度最高，平均达到2.34×10拷贝/（克污泥）。在此条件下，comammox硝化螺旋菌和氨氧化古菌贡献了高达94%的总硝化活性，而氨氧化细菌仅占6%。总体而言，证实了QS在comammox硝化螺旋菌富集中的作用，信号分子显著加速了comammox硝化螺旋菌的生长，促进了功能酶活性，并增强了硝化细菌的竞争力。在所测试的信号分子中，C8-HSL表现出最显著的促进作用，其次是C6-HSL和C12-HSL。以添加C8-HSL的缺氧池污泥作为种子污泥为comammox硝化螺旋菌提供了一种快速可靠的富集策略。这些发现为QS在comammox细菌富集中的作用提供了见解，并可能促进基于comammox硝化螺旋菌的废水处理生物技术的发展。
