title: Microbial functional genes enriched in the Xiangjiang River sediments with heavy metal contamination.
abstract: Xiangjiang River (Hunan, China) has been contaminated with heavy metal for several decades by surrounding factories. However, little is known about the influence of a gradient of heavy metal contamination on the diversity, structure of microbial functional gene in sediment. To deeply understand the impact of heavy metal contamination on microbial community, a comprehensive functional gene array (GeoChip 5.0) has been used to study the functional genes structure, composition, diversity and metabolic potential of microbial community from three heavy metal polluted sites of Xiangjiang River.
  
  
  
  A total of 25595 functional genes involved in different biogeochemical processes have been detected in three sites, and different diversities and structures of microbial functional genes were observed. The analysis of gene overlapping, unique genes, and various diversity indices indicated a significant correlation between the level of heavy metal contamination and the functional diversity. Plentiful resistant genes related to various metal were detected, such as copper, arsenic, chromium and mercury. The results indicated a significantly higher abundance of genes involved in metal resistance including sulfate reduction genes (dsr) in studied site with most serious heavy metal contamination, such as cueo, mer, metc, merb, tehb and terc gene. With regard to the relationship between the environmental variables and microbial functional structure, S, Cu, Cd, Hg and Cr were the dominating factor shaping the microbial distribution pattern in three sites.
  
  
  
  This study suggests that high level of heavy metal contamination resulted in higher functional diversity and the abundance of metal resistant genes. These variation therefore significantly contribute to the resistance, resilience and stability of the microbial community subjected to the gradient of heavy metals contaminant in Xiangjiang River.
authors: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
authors: Shiqi
authors: S
authors: Jie
authors: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
authors: Mingming
authors: M
authors: Li
authors: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
authors: Min
authors: M
authors: Gan
authors: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China. zhujy@mail.csu.edu.cn.
authors: Jianyu
authors: 0000-0001-5245-0845
authors: J
authors: Zhu
authors: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China. yinhuaqun@gmail.com.|Department of Botany and Microbiology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, 73019, USA. yinhuaqun@gmail.com.
authors: Huaqun
authors: H
authors: Yin
authors: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
authors: Xueduan
authors: X
authors: Liu
mesh_terms: D002681:China; D016000:Cluster Analysis; D015342:DNA Probes; D004784:Environmental Monitoring / Q000379:methods; D005807:Genes, Overlapping; D014644:Genetic Variation; D062305:Geographic Mapping; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D019216:Metals, Heavy / Q000032:analysis*; D059013:Microbial Consortia / Q000235:genetics*; D045483:Rivers / Q000737:chemistry* / Q000382:microbiology*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D015342:DNA Probes; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: GeoChip; Heavy metal contamination; Metal resistance; Microbial functional gene; Xiangjiang river