Effect of heavy metal contamination on bacterial community structure in paddy fields of South Korea

Soils were collected along the vicinity of a copper and gold smelter in Janghang town located in Seocheon County in South Chungcheong Province,South Korea. Soil samples were collected at a depth of 0-30 cm from paddy soils located at three different locations and were named based on their distances from the refinery center. Site 1 was located 260 m from the smelter and contained significantly high levels of arsenic. Site 2 was located 240 m from the smelter and had been designated as part of an initial phytoremediation project.Site 3 consisted of rice paddy soil located 3500 m from the smelter and represented an area of low contamination. Soil sampling was done from three randomly selected areas within each site. Each area represented a replicate sample of a single site, and consisted of top and subsoils from three adjacent spots which were approximately 1 m away from each other.The three subsamples were mixed together to make it one composite sample for each site.Thus S1-1,S1-2 and S1-3 are replicate samples from Site 1,S2-1,S2-2 and S2-3 are replicate samples from Site 2 and S3-1,S3-2 and S3-3 are replicate samples from Site 3.