Responses of activities, abundances and community structures of soil denitrifiers to short-term mercury stress

• Published in: Journal of environmental sciences (China) Vol. 24; no. 3; pp. 369 - 375
• Main Authors: Zhou, Zhifeng, Zheng, Yuanming, Shen, Jupei, Zhang, Limei, Liu, Yurong, He, Jizheng
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2012; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,Beijing 100085, China; College of Resources and Environment, Southwest University, Chongqing 400716, China%State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,Beijing 100085, China; Graduate School of Chinese Academy of Sciences, Beijing 100039, China
• Subjects: Bacteria - drug effects; Bacteria - enzymology; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cluster Analysis; Communities; community structure; denaturing gradient gel electrophoresis; Denitrification; denitrification enzyme activity; denitrifying microorganisms; DGGE; Drying; enzyme activity; Gene Expression Regulation, Bacterial - drug effects; Genes; Hg100; Mercury; Mercury - toxicity; nirS; nitrous-oxide reductase; nosZ; Polymerase Chain Reaction; quantitative polymerase chain reaction; real-time PCR; Reductases; soil; Soil (material); Soil - chemistry; Soil Microbiology; Soil Pollutants - toxicity; Stimulation; Stresses; Time Factors; 低丰度; 反硝化细菌; 变性梯度凝胶电泳; 土壤处理; 汞胁迫; 短期; 群落结构; nosZ; real-time PCR; denitrification enzyme activity; DGGE; Hg; nirS
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/S1001-0742(11)60747-X

The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.