Microbial Community Structure Of The AMD And Their Dynamics Under Different Conditions Of Enrichment

The acid mine drainage, commonly referred to as acid mine drainage(AMD), has become an economic and environmental burden. Thousandsupon thousands streams, rivers, lakes and reservoirs worldwide had beenseriously damaged by mine effluents, although the true scale of theenvironmental pollution caused by mine water discharges is difficult toassess accurately。The major producer of such effluents is the miningindustry. Waters draining active and, in particular, abandoned mines andmine wastes are often net acidic. Such waters typically pose an additionalrisk to the environment by the fact that they often contain elevatedconcentrations of metals (iron, aluminium and manganese, and possiblyother heavy metals) and metalloids. So, there is an important significanceto understand the composition and structure of microorganisms in acidmine drainage。The Dongchuan copper mining district locate in the eastern part ofYunnan Province, China and has a mining history of more than 400 yearsand now it is still one of the three major copper producers in China.Because the mine locates at the mountain and the altitude is more than1800 meters, the climate is different with the same latitudinal area. Thetemperature is low approximately 10℃and the temperature of water isless than 20℃in summer. Dongcguan copper mine is a representativeof the Dongchuan copper deposit s and its abundant copper resources andcomplicated evolutionary history have aroused great interest of thegeological circles. Understanding of the composition and structure ofmicroorganisms of Dongchuang copper mine could help to prevent acidmine drainage, protect the environment and This study researched thegeochemistry character of three sites of Dongchuang copper mine,assessed the community composition of acid mine drainage by 16s rRNAgene clone libraries, and debated the influence of the geochemistrycharacter, temperature, pH value and the ion concentration formicroorganism community structure.PCR-RFLP analysis was used to study the microbial community of three acid mine drainage from Dongchuan copper pyrite, China, whichlocate in the eastem part of Yunnan Province and has a mining history ofmore than 400 years and now is still one of the three major copperproducers in China. 16s rRNA genes were amplified, subsequently clonedand detected by a restriction fragment length polymorphism (RFLP)analysis. A total of 357 clones were grouped into 100 operationaltaxonomic units (OTUs) by the RFLP analysis and 58 OTUs weresequenced. The phylogenetic analysis revealed that all sequences wereclustered to six groups (γ-Proteobacteria, Acidobacteria, Clostridia,Actinobacteria, Nitrospira,α-Proteobacteria families),α-Proteobacteriafamily was the dominant groups in three sites. However, only fewacidophilic microorganisms were detected and they were respectivelyaffiliated with At.ferrooxidans and L. ferrooxidans. This study researchedthe geochemistry character of three sites of Dongchuang copper mine,evaluated the community composition of acid mine drainage by 16srRNA gene clone libraries and debated the influence of the geochemistrycharacter, temperature, pH value and the ion concentration formicroorganism community structure and we considered that perenniallow temperature (even less 20℃in summer) may be the primarycausation that At. Ferrooxidans and L. ferrooxidans was both not thedominated species.We analyzed and compared community structural variety in originaland back of microorganisms using different energy sources culturedAMD water, discovered when using different energy sources, themicroorganisms fall structure each not same, for example while makinguse of the ferrous iron as energy of main microorganism isAciditiobacillus ferrooxidans, other microorganisms such as L.Ferrooxidan, Acidiphilium sp was as a handful of exist. But making useof the sulphur powder as energy sources Acidithiobacillus ferrooxidansand Leptospirillum ferrooxidans were main microorganism, others had nodetection. However, while adding ferrous iron in addition sulphur powderfor the energy resource regarded the Acidiphilium sp and theAcidithiobacillus ferrooxidans as dominative, adding yeast powder withthe ferrous iron and sulphur powder but took Leptospirillum ferrooxidans as main existent microorganism, also a little amount of othermicroorganisms exist.Using the original AMD waste water enriching cultured by the 9Kculture medium to process the mineral, we discovered the pH value andmineral concentration were the great influence factors of the copperbioleaching, when the pH value shifted from low to high, the copper ironbioleaching result from high to low variety, and at the mineralconcentration changed from low to high, the result also was from high tolow variety.