Excessive nitrate in waterbody, which usually leads to eutrophication, can be removed by microbial denitrification processes. However, denitrification rate is greatly constrained by the spatial separation of nitrate in the upper oxic water layer from the electron donors close to the anoxic sediment. Herein, we constructed a genetically engineered bacterium (GEB), by co-expressing MO2.1 from Moringa oleifera and FLO5 from Saccharomyces cerevisiae, to simultaneously adsorb and self-flocculate nitrate from water. The GEB could migrate 45.5% of the nitrate to the bottom layer in actual water. Expressed FLO5 is electrically neutral and could trigger bacterial flocculation under the mediation of extracellular polysaccharides. Certain cationic arginine sites in MO2.1 can form strong electrostatic adsorption with NO₃^-, achieving bacterial self-flocculation, sedimentation and nitrate removal. The construction of multifunctional GEB could realize waterbody nitrate migration and is important to studies on new functional bacteria, water purification technology as well as geochemical nitrogen cycle.

水体中过量的硝酸盐通常会导致富营养化，可以通过微生物反硝化工艺将其去除。但是，反硝化速率受到上部含氧水层中硝酸盐与靠近缺氧沉积物的电子供体的空间分离的极大限制。本文中，我们通过共表达来自辣木的MO2.1和来自酿酒酵母的FLO5，共构建了基因工程细菌（GEB）。，以同时从水中吸附和自絮凝硝酸盐。GEB可以将45.5％的硝酸盐迁移到实际水中的底层。表达的FLO5是电中性的，并可能在细胞外多糖的介导下引发细菌絮凝。在MO2.1某些阳离子精氨酸位点可形成强的静电吸附与NO ₃ ^- ，实现细菌自絮凝，沉淀和硝酸盐去除。多功能GEB的构建可以实现水体硝酸盐的迁移，对于研究新的功能细菌，水净化技术以及地球化学氮循环具有重要意义。