The responses of nitrification and denitrification to the divalent zinc (Zn(II)) and tetracycline (TC) co-selective pressure were evaluated in a sequencing batch reactor (SBR). The removal rates of organics and nitrogen, nitrifying and denitrifying enzymatic activity, and microbial diversity and richness at the Zn(II) and TC co-selective pressure were higher than those at the alone Zn(II) selective pressure, while were lower than those at the individual TC selective pressure. The Zn(II) and TC co-selective pressure induced the TC resistance genes abundance increase and the Zn(II) resistance genes levels decrease, and enhanced bacterial enzymatic modification resistance to TC and bacterial outer membrane resistance to Zn(II). The network analysis showed that the genera Nitrospira and Nitrosomonas of nitrifiers and the genera Ferruginibacter, Dechloromonas, Acidovorax, Rhodobacter, Thauera, Cloacibacterium, Zoogloea and Flavobacterium of denitrifiers were the potential hosts of antibiotics resistance genes (ARGs) and/or heavy metals resistance genes (HMRGs).

在顺序分批反应器（SBR）中评估了硝化和反硝化对二价锌（Zn（II））和四环素（TC）共选择压力的响应。Zn（II）和TC共选择压力下的有机物和氮的去除率，硝化和反硝化酶活性以及微生物多样性和丰富度均高于单独的Zn（II）选择压力下的水平，但低于这些在各个TC选择压力下。Zn（II）和TC共选择压力诱导TC抗性基因丰度增加，而Zn（II）抗性基因水平降低，并增强了细菌对TC的酶促修饰抗性和细菌对Zn（II）的外膜抗性。网络分析表明，硝化螺菌属和亚硝化单胞菌属硝化剂的组成以及反硝化剂的费氏杆菌属，脱氯莫纳斯菌，嗜酸杆菌属，红细菌属，索拉属，梭菌属，兽类属和黄杆菌属是抗生素抗性基因（ARG）和/或重金属抗性基因（HMRGs）的潜在宿主。