School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China; School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China.
Water Res. 2021 Nov 1;206:117742. doi: 10.1016/j.watres.2021.117742. Epub 2021 Oct 7.
Thauera, as one of the core members of wastewater biological treatment systems, plays an important role in the process of nitrogen and phosphorus removal from low-carbon source sewage. However, there is a lack of systematic understanding of Thauera's metabolic pathway and genomics. Here we report on the newly isolated Thauera sp. RT1901, which is capable of denitrification using variety carbon sources including aromatic compounds. By comparing the denitrification processes under the conditions of insufficient, adequate and surplus carbon sources, it was found that strain RT1901 could simultaneously use soluble microbial products (SMP) and extracellular polymeric substances (EPS) as electron donors for denitrification. Strain RT1901 was also found to be a denitrifying phosphate accumulating bacterium, able to use nitrate, nitrite, or oxygen as electron acceptors during poly-β-hydroxybutyrate (PHB) catabolism. The annotated genome was used to reconstruct the complete nitrogen and phosphorus metabolism pathways of RT1901. In the process of denitrifying phosphorus accumulation, glycolysis was the only pathway for glycogen metabolism, and the glyoxylic acid cycle replaced the tricarboxylic acid cycle (TCA) to supplement the reduced energy. In addition, the abundance of conventional phosphorus accumulating bacteria decreased significantly and the removal rates of total nitrogen (TN) and chemical oxygen demand (COD) increased after the addition of RT1901 in the low carbon/nitrogen (C/N) ratio of anaerobic aerobic anoxic-sequencing batch reactor (AOA-SBR). This research indicated that the diverse metabolic capabilities of Thauera made it more competitive than other bacteria in the wastewater treatment system.
陶厄氏菌作为废水生物处理系统的核心成员之一，在低碳源污水脱氮除磷过程中发挥着重要作用。然而，人们对陶厄氏菌的代谢途径和基因组学缺乏系统的认识。在这里，我们报告了一种新分离的陶厄氏菌 RT1901，它能够利用各种碳源（包括芳香族化合物）进行反硝化。通过比较在碳源不足、充足和过剩条件下的反硝化过程，发现菌株 RT1901可以同时将可溶性微生物产物（SMP）和细胞外聚合物（EPS）作为电子供体用于反硝化。研究还发现，菌株 RT1901 是一种反硝化聚磷菌，能够在聚-β-羟基丁酸（PHB）分解代谢过程中利用硝酸盐、亚硝酸盐或氧气作为电子受体。通过对注释基因组的分析，重建了 RT1901 的完整氮磷代谢途径。在反硝化聚磷过程中，糖酵解是糖原代谢的唯一途径，而乙醛酸循环取代三羧酸循环（TCA）来补充还原能。此外，在低碳氮（C/N）比的厌氧好氧缺氧序批式反应器（AOA-SBR）中添加 RT1901 后，传统聚磷菌的丰度显著降低，总氮（TN）和化学需氧量（COD）的去除率也有所提高。本研究表明，陶厄氏菌多样的代谢能力使其在废水处理系统中比其他细菌更具竞争力。
