Studies On The Structure Of Microbial Communities Of Acidic Environment At The Dexing Copper Mine Based On RFLP And Microarray

The acid mine drainage,commonly referred to as acid mine drainage (AMD),has become an economic and environmental burden.Such waters typically pose an additional risk to the environment by the fact that they often contain elevated concentrations of metals(iron,aluminium and manganese, and possibly other heavy metals)and metalloids.So,there is an important significance to understand the composition and structure of microorganisms in acid mine drainage.So,study the microbial community and their functional activity of acid mine drainage have a great importance.We use RFLP technology based on the 16S rRNA gene as the molecular marker and the microarray that have been constructed and evaluated by our laboratory to study the microbial compositions of Dexing copper mine,Jiangxi province.And We also use RFLP technology based on the 16S rRNA gene as the molecular marker to analyzed and compared community structural variety in original and back of microorganisms using different energy sources cultured AMD water.Microbial diversity of acid mine drainage and sediment samples from three sites within the mine were analyzed by 16S rRNA gene library and restriction fragment length polymorphism(RFLP)analysis.A total of 40 unique 16S rRNA genes,screened from 558 clones,were obtained from all sites.The sequenced clones fell into seven phylogenetic divisions.The majority of the clones were affiliated with theγ-Proteobacteria,α-Proteobacteria and Nitrospira.At all sites examined,the proportion of Acidithiobacillus ferrooxidans in the acid mine drainage is greater than that in the sediment.In contrast,the proportion of Acidiphilium is greater in the sediment than that in the acid mine drainage.This may be due to the anaerobic environment within the sediment,which inhibited aerobic bacteria,such as A. ferrooxidans.However,Acidiphilium,a heterotrophic bacterium,is able to catalyze the dissimilatory reduction of ferric iron to ferrous even in the presence of small amounts of oxygen.We analyzed and compared community structural variety in original and back of microorganisms using different energy sources cultured AMD water, when using different energy sources,the microorganisms fall structure each not same.While making use of the ferrous iron as energy,the main microorganism is Aciditiobacillus ferrooxidans and Leptospirillum Ferrooxidan,other microorganisms such as Acidiphilium was as a handful of exist.But making use of the sulphur powder as energy sources, Acidithiobacillus ferrooxidans were main microorganism,Leptospirillum ferrooxidans and others had no detection.However,while adding ferrous iron and sulphur powder for the energy resource,the Acidithiobacillus ferrooxidans as dominative,adding yeast powder with the ferrous iron and sulphur powder, the Leptospirillum ferrooxidans as main existent microorganism,also a little amount of other microorganisms exist.Microarray technology has been widely used in researches concerning the function and structure of microbial community due to its unique advantages. We use the microarray that have been constructed and evaluated by our laboratory to detect the microbial community compositions and functional activities of the three sediment samples of Dexing copper mine.The result showed community composed by 15 different genus or species,including Acidithiobacillus ferrooxidans,Leptospirillum sp.,Acidiphilum spp.,Acidithiobacillus thiooxidans,Acidobacteria,Acidithiobacillus caldus,Sulfobacillus sp.,DesuIfovibrio longus,Syntrophus sp.,metallosphaera,Alicyclobacillus spp.,Holophaga sp.,Sulfolobus sp.,Thiomonas spp.and Actinomyces naeslundii.This result is same to RFLP.