Efficacy of simultaneous hexavalent chromium biosorption and nitrogen removal by the aerobic denitrifying bacterium Pseudomonas stutzeri YC-34 from chromium-rich wastewater

作者：Keyin Yang, Huijun Bu, Ying Zhang, Hongxia Yu, Sining Huang, Lixia Ke, Pei Hong · 发表于：Frontiers in Microbiology · 年份：2022 · DOI：10.3389/fmicb.2022.961815 · 被引用次数：14 · 研究领域：Wastewater Treatment and Nitrogen Removal、Chromium effects and bioremediation、Adsorption and biosorption for pollutant removal

The impact of high concentrations of heavy metals and the loss of functional microorganisms usually affect the nitrogen removal process in wastewater treatment systems. In the study, a unique auto-aggregating aerobic denitrifier ( Pseudomonas stutzeri strain YC-34) was isolated with potential applications for Cr(VI) biosorption and reduction. The nitrogen removal efficiency and denitrification pathway of the strain were determined by measuring the concentration changes of inorganic nitrogen during the culture of the strain and amplifying key denitrification functional genes. The changes in auto-aggregation index, hydrophobicity index, and extracellular polymeric substances (EPS) characteristic index were used to evaluate the auto-aggregation capacity of the strain. Further studies on the biosorption ability and mechanism of cadmium in the process of denitrification were carried out. The changes in tolerance and adsorption index of cadmium were measured and the micro-characteristic changes on the cell surface were analyzed. The strain exhibited excellent denitrification ability, achieving 90.58% nitrogen removal efficiency with 54 mg/L nitrate-nitrogen as the initial nitrogen source and no accumulation of ammonia and nitrite-nitrogen. Thirty percentage of the initial nitrate-nitrogen was converted to N 2 , and only a small amount of N 2 O was produced. The successful amplification of the denitrification functional genes, norS, norB, norR , and nosZ , further suggested a comple...