Three samples of acid mine drainage (AMD) collected from Dabaoshan Mine (Guangdong Province, China) were studied. In addition to physico-chemical analyses, bacterial diversities and community structures of these samples were described at genetic level by amplified ribosomal DNA restriction analysis (ARDRA). A total of 60 different ARDRA patterns were obtained from 377 clones and were studied as operational taxonomic units (OTUs), which were re-amplified and sequenced. The sequence data and phylogenetic analysis showed that Acidithiobacillus ferrooxidans represented 88.0% of the bacterial population in Sample LC. However, Samples JX and FS contained more diverse colonies of bacteria, such as Leptospirillum ferrooxidans (JX: 16.9%, FS: 39.1%), Acidiphilum sp. (JX: 38.7%, FS: 25.8%) and A. ferrooxidans (JX: 12.1%, FS: 10.2%). These diversities were characterized by the reciprocal of Simpson's index (1/D) and correlated with the concentrations of ferrous iron and toxic ions in AMD.KEY WORDS: Bacterial diversity · Microbial community · Acid mine drainage · Amplified ribosomal DNA restriction analysis Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 47: [141][142][143][144][145][146][147][148][149][150][151] 2007 (e.g. Coram & Rawlings 2002, Kormas et al. 2006) have been conducted.New studies (since the 90s) on AMD from diverse geographical locations have revealed that many uncultured bacteria might be very important in the generation of acidic environments (Golyshina et al. 2000), and that AMD supports a diverse range of iron-and sulfuroxidizing chemolithotrophs as well as heterotrophic microorganisms (Johnson 1998). Community structure varies among diverse geographical locations, revealing that AMD niches and changes in dominant bacterial species are affected by geographical conditions.Studies of bacterial diversity and community structure in diverse AMD can help us to reveal principal bacterial species for mine dissolution in different geographical conditions, and the factors that affect such bacterial communities. To date, although there are many existing reports on bacterial ecology in AMD, to the best of our knowledge such studies in Chinese mines are rare. In this study, we investigated the bacterial and geochemical characteristics of 3 AMD sites in Dabaoshan Mine, Guangdong Province, China. The genomic DNA of the bacterial community at each site was extracted. Subsequently, Amplified Ribosomal DNA Restriction Analysis (ARDRA) was used to analyze the bacterial communities that occur at these sites, and the findings were correlated with the determined geochemistry and mineralogy of each site. MATERIALS AND METHODSStudy site, sample collection and physicochemical analyses. Dabaoshan Mine (24°31' 37'' N, 113°42' 49'' E) is located in the mountainous area of the northern part of Guangdong Province, China. It is a large, multi-metallic mineral deposit: the top of the main ore body appears to be a limonite body, while the lower body contains copper sulphur c...

Three acid mine drainage (AMD) samples collected from Dabaoshan Mine (Guangdong Province, China) were studied. In addition to physicochemical analyses, the diversity and community structures of the archaeal communities in these samples were described at the genetic level by amplified ribosomal DNA restriction analysis (ARDRA). Nine different ARDRA patterns were obtained from 146 clones and were studied as operational taxonomic units (OTUs), which were re-amplified and sequenced. Sequence data and phylogenetic analysis showed that most of the clones belonged to the Thermoplasmatales, and that archaea belonging to the Sulfolobales were absent. Only 1 OTU attributed to Ferroplasma was found and was observed to be abundant in all 3 samples. Eight OTUs were related to 2 new undefined groups in the Thermoplasmatales. Of the 8 OTUs, the clones in 2 similar units were isolated from samples collected from an abandoned sulfide mine (Huelva, Spain) and those in 5 similar units were isolated from samples collected from a closed copper mine (Tonglushan, China). These diversities were characterized by the reciprocal of Simpson's index (1/D) and correlated with the concentrations of ferrous ions and toxic ions in the AMD samples. The high temperature of the sampling sites was one of the factors that could explain why archaea belonging to the Thermoplasmatales were abundant in the analyzed AMD samples while those belonging to the Sulfolobales were absent.