Shen Shanrui, Zhou Yiyi, Cheng Hongli, Qian Han, Wen Jun, Lin Chunmei, Lai Xiaofang
Jiangsu Key Laboratory of Marine Bioresources and Environment, Key Laboratory of Marine Biological Resources and Environment of Jiangsu Province, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, PR China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Lianyungang 222005, PR China; Marine Resource Development institute of Jiangsu (Lianyungang), Lianyungang 222005, PR China; The Jiangsu Provincial Platform for Conservation and Utilization of Agricultural Germplasm, Nanjing 210014, PR China.
Jiangsu Key Laboratory of Marine Bioresources and Environment, Key Laboratory of Marine Biological Resources and Environment of Jiangsu Province, School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, PR China.
Sci Total Environ. 2025 Aug 2;996:180187. doi: 10.1016/j.scitotenv.2025.180187.
Eutrophication of aquatic ecosystems, primarily induced by the excessive accumulation of nitrogen compounds from aquaculture activities, poses significant environmental challenges. To address this issue through biological denitrification, a total of 17 strains with aerobic denitrification activity were isolated from river prawn pond using selective media. Among these isolates, strain QX11 exhibited the highest denitrification activity and was consequently selected for further investigation. Phylogenetic analysis identified strain QX11 as showing highest homology (98.32 %) with Pseudomonas mendocina, with optimal growth and denitrification performance observed at a C/N ratio of 10, salinity of 5, temperature of 30 °C and rotational speed of 150 rpm. Under these optimized conditions, QX11 exhibited remarkable nitrogen removal efficiencies: achieving 98.06 % NH-N removal when NHCl served as the sole nitrogen source; 97.9 % NO-N removal with KNO as the sole nitrogen source, and simultaneous removal rates of 98.96 % NH-N and 96.5 % NO-N in mixed nitrogen sources (NHCl and KNO), while accumulating only negligible amounts of NO-N regardless of nitrogen source composition. The biosafety assessment revealed that QX11 demonstrated sensitivity to most tested antibiotics and exhibited no hemolytic activity. Experimental trials with river shrimp showed no significant difference (P > 0.05) in mortality rates between QX11-treated and control groups. In simulated aquaculture effluent treatment systems, QX11 exhibited exceptional bioremediation performance, achieving removal efficiencies of 99.74 % for NH-N, 97.98 % for NO-N, 99.63 % for NO-N, and 97.44 % for COD. Notably, QX11 inoculation significantly altered the microbial community composition in the moving bed biofilm reactor (MBBR), particularly affecting the relative abundance of dominant phyla and genera. These comprehensive results demonstrate that QX11 represents an efficient and environmentally safe aerobic denitrifying bacteria, providing a promising biological solution for mitigating water eutrophication in aquaculture and treating various types of nitrogen-contaminated wastewater.
水生生态系统的富营养化主要由水产养殖活动中氮化合物的过度积累引起，带来了重大的环境挑战。为了通过生物反硝化解决这一问题，使用选择性培养基从河虾池塘中分离出了总共17株具有好氧反硝化活性的菌株。在这些分离株中，菌株QX11表现出最高的反硝化活性，因此被选作进一步研究。系统发育分析确定菌株QX11与门多萨假单胞菌具有最高的同源性（98.32%），在C/N比为10、盐度为5、温度为30℃和转速为150转/分钟时观察到最佳生长和反硝化性能。在这些优化条件下，QX11表现出显著的脱氮效率：当氯化铵作为唯一氮源时，实现了98.06%的氨氮去除率；以硝酸钾作为唯一氮源时，实现了97.9%的亚硝酸盐氮去除率，在混合氮源（氯化铵和硝酸钾）中氨氮和亚硝酸盐氮的同步去除率分别为98.96%和96.5%，无论氮源组成如何，仅积累少量的硝酸盐氮。生物安全性评估表明，QX11对大多数测试抗生素敏感，且无溶血活性。对河虾的实验表明，经QX11处理的组和对照组之间的死亡率没有显著差异（P>0.05）。在模拟水产养殖废水处理系统中，QX11表现出卓越的生物修复性能，氨氮去除率达到99.74%，亚硝酸盐氮去除率达到97.98%，硝酸盐氮去除率达到99.63%，化学需氧量去除率达到97.44%。值得注意的是，接种QX11显著改变了移动床生物膜反应器（MBBR）中的微生物群落组成，特别是影响了优势菌门和菌属的相对丰度。这些综合结果表明，QX11是一种高效且环境安全的好氧反硝化细菌，为减轻水产养殖中的水体富营养化和处理各类含氮污染废水提供了一种有前景的生物解决方案。
