重金属和抗生素胁迫对亚硝酸盐氧化菌及硝化菌群活性的影响

重金属和抗生素广泛存在工业废水、养殖水体中,对硝化细菌活性有不同程度的影响.为研究重金属和抗生素胁迫对亚硝酸盐氧化菌(nitrite-oxidizing bacteria,NOB)及硝化菌群活性的影响,采集珠江水样富集硝化菌群并分离纯化NOB,研究了不同浓度重金属离子(Cu2+、Zn2+、Cd2+、Mn2+、Cr6+)...

Effects of heavy metal and antibiotic stresses on the activity of nitrite-oxidizing bacteria and nitrifying bacteria flora

Heavy metals and antibiotics are widely distributed in industrial wastewater and aquaculture water, which have varying degrees of impact on the activity of nitrifying bacteria. In order to study the effects of heavy metals and antibiotics on the nitrite oxidation of nitrite-oxidizing bacteria (NOB) and nitrifying bacteria flora, water sample of the Pearl River was collected to enrich and cultivate nitrifying bacteria flora and isolate NOB, then the effects of different concentrations of heavy metal ions (Cu2+, Zn2+, Cd2+, Mn2+, Cr6+) and antibiotics (kanamycin, ampicillin, streptomycin and tetracycline hydrochloride) on the nitrite oxidation activity of NOB were studied to reveal the effects of heavy metals and antibiotics stresses on the activities of nitrifying bacteria flora and NOB. The results showed that the abundance of Nitrosomonas in the nitrifying bacteria flora after the 15th times enrichment increased from 0.11% to 10.04%, and the abundance of Nitrobacter increased from 0.014% to 2.104%. The isolated and purified NOB was closely related to Nitrobacter winogradskyi, showing a similarity of 99.58%. The nitrite oxidation activity of NOB decreased with the increase of the concentration of heavy metal ions and antibiotics; in comparison with NOB, the nitrifying bacteria flora under the stress of heavy metals and antibiotics had a higher nitrite oxidation rate, more stable and stronger stress resistance to heavy metals and antibiotics, which indicates it has a greater potential on the practical application in nitrogenous wastewater treatment. The results provide a theoretical reference for the research of NOB and its development and application in industry and aquaculture water purification.