Waste ore samples （pH 3.0） were collected at an acid mine drainage （AMD） site in Anhui, China. The present acidophillc microbial community in the waste ore was studied with 16S rRNA gene clone library and denaturi...Waste ore samples （pH 3.0） were collected at an acid mine drainage （AMD） site in Anhui, China. The present acidophillc microbial community in the waste ore was studied with 16S rRNA gene clone library and denaturing gradient gel electrophoresis （DGGE）. Eighteen different clones were identified and affiliated withActinobacteria, low G ＋ C Gram-positives, Thermomicrobia, Acidobacteria, Proteobacteria, candidate division TM7, and Planctomycetes. Phylogenetic analysis of 16S rRNA gene sequences revealed a diversity of acidophiles in the samples that were mostly novel. It is unexpected that the moderately thermophilic acidophiles were abundant in the acidic ecosystem and may play a great role in the generation of AMD. The result of DGGE was consistent with that of clone library analysis. These findings help in the better understanding of the generation mechanism of AMD and in developing a more efficient method to control AMD.展开更多
The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene ...The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene clone library analysis.The total bacteria numbers are reduced when 0.5%(volume fraction) extractant is added.The proportions of Acidithiobacillus ferrooxidans and Acidiphilium organovorum are increased,whereas the proportion of Leptospirillum ferriphilum is reduced.When the concentration of extractant is elevated to 1%,growth of all bacteria is inhibited.Clone library results reveal that the dominant bacteria in the culture solution with/without the extractant are At.ferrooxidans,A.organovorum and L.ferriphilum.The sensitivity order of the three bacteria to the extractant from the most to the least is found to be L.ferriphilum>At.ferrooxidans>A.organovorum.展开更多
A gram-positive, rod-shaped, aerobic, thermo-acidophilic bacterium CC2 （optimal temperature 55℃ and pH 4.0）, belonging to the genus Alicyclobacillus was isolated from geothermal soil collected from ＂Cerro Caliente...A gram-positive, rod-shaped, aerobic, thermo-acidophilic bacterium CC2 （optimal temperature 55℃ and pH 4.0）, belonging to the genus Alicyclobacillus was isolated from geothermal soil collected from ＂Cerro Caliente＂, Deception Island, Antarctica. Owing to the harsh environmental conditions found in this territory, microorganisms are exposed to conditions that trigger the generation of reactive oxygen species （ROS）. They must have an effective antioxidant defense system to deal with this oxidative stress. We focused on one of the most important enzymes： superoxide dismutase, which was partially purified and characterized. This study presents the first report of a thermo-acidophilic bacterium isolated from Deception lsland with a thermostable superoxide dismutase （SOD）.展开更多
Heap bioleaching is one of the most clean and economical processes for recovery of low-grade and complex ores, because the sulfide minerals are natural habitats for acidophiles capable of iron-and sulfur-oxidation. Th...Heap bioleaching is one of the most clean and economical processes for recovery of low-grade and complex ores, because the sulfide minerals are natural habitats for acidophiles capable of iron-and sulfur-oxidation. The most exciting advances in heap bioleaching are occurring in the field of microbiology, especially with the development of advanced molecular biology approaches. These chemolithotrophic microorganisms living in the acid mine environment fix N_2 and CO_2 and obtain energy for growth from soluble ferrous iron and reduced inorganic sulfur compounds during oxidation of sulfide minerals. The ferric iron as oxidant and sulfuric acid are a result of microbial activity and provide favorable conditions for the dissolution of sulfide minerals. Various microbial consortia were applied successfully in commercial bioleaching heaps around the world, and microbial community and activity were adapted related to the local climatic conditions, ore characteristics and engineering configuration. This review focuses on diversity of bioleaching microbes, their role in heap bioleaching processes, their community structure and function in industrial heaps and the relation to the ore characteristics and the engineering configuration, to give implications for optimizing leaching efficiency of heap bioleaching.展开更多
基金Project supported by the National Basic Research Program of China (No. 2004CB719704).
文摘Waste ore samples （pH 3.0） were collected at an acid mine drainage （AMD） site in Anhui, China. The present acidophillc microbial community in the waste ore was studied with 16S rRNA gene clone library and denaturing gradient gel electrophoresis （DGGE）. Eighteen different clones were identified and affiliated withActinobacteria, low G ＋ C Gram-positives, Thermomicrobia, Acidobacteria, Proteobacteria, candidate division TM7, and Planctomycetes. Phylogenetic analysis of 16S rRNA gene sequences revealed a diversity of acidophiles in the samples that were mostly novel. It is unexpected that the moderately thermophilic acidophiles were abundant in the acidic ecosystem and may play a great role in the generation of AMD. The result of DGGE was consistent with that of clone library analysis. These findings help in the better understanding of the generation mechanism of AMD and in developing a more efficient method to control AMD.
基金Project(50904011) supported by the National Natural Science Foundation of China
文摘The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene clone library analysis.The total bacteria numbers are reduced when 0.5%(volume fraction) extractant is added.The proportions of Acidithiobacillus ferrooxidans and Acidiphilium organovorum are increased,whereas the proportion of Leptospirillum ferriphilum is reduced.When the concentration of extractant is elevated to 1%,growth of all bacteria is inhibited.Clone library results reveal that the dominant bacteria in the culture solution with/without the extractant are At.ferrooxidans,A.organovorum and L.ferriphilum.The sensitivity order of the three bacteria to the extractant from the most to the least is found to be L.ferriphilum>At.ferrooxidans>A.organovorum.
基金supported by projects Gabinete G04-09 from INACH and Grant Innova-CORFO No 07CN13PXT-264
文摘A gram-positive, rod-shaped, aerobic, thermo-acidophilic bacterium CC2 （optimal temperature 55℃ and pH 4.0）, belonging to the genus Alicyclobacillus was isolated from geothermal soil collected from ＂Cerro Caliente＂, Deception Island, Antarctica. Owing to the harsh environmental conditions found in this territory, microorganisms are exposed to conditions that trigger the generation of reactive oxygen species （ROS）. They must have an effective antioxidant defense system to deal with this oxidative stress. We focused on one of the most important enzymes： superoxide dismutase, which was partially purified and characterized. This study presents the first report of a thermo-acidophilic bacterium isolated from Deception lsland with a thermostable superoxide dismutase （SOD）.
基金supported by the European Commission under the Sixth Framework Programme for Research and Development in the frame of the research projects BioMinE(European project contract NMP1-CT-500329-1)Bioshale(European project contract NMP2-CT-2004 505710)The author is also grateful to the Royal Society(U.K.)for the provision of an Industrial Fellowship.
基金funded by the National Natural Science Foundation of China(41401541,51674231)Bureau of International Co-operation,Chinese Academy of Sciences(122111KYSB20150013)
文摘Heap bioleaching is one of the most clean and economical processes for recovery of low-grade and complex ores, because the sulfide minerals are natural habitats for acidophiles capable of iron-and sulfur-oxidation. The most exciting advances in heap bioleaching are occurring in the field of microbiology, especially with the development of advanced molecular biology approaches. These chemolithotrophic microorganisms living in the acid mine environment fix N_2 and CO_2 and obtain energy for growth from soluble ferrous iron and reduced inorganic sulfur compounds during oxidation of sulfide minerals. The ferric iron as oxidant and sulfuric acid are a result of microbial activity and provide favorable conditions for the dissolution of sulfide minerals. Various microbial consortia were applied successfully in commercial bioleaching heaps around the world, and microbial community and activity were adapted related to the local climatic conditions, ore characteristics and engineering configuration. This review focuses on diversity of bioleaching microbes, their role in heap bioleaching processes, their community structure and function in industrial heaps and the relation to the ore characteristics and the engineering configuration, to give implications for optimizing leaching efficiency of heap bioleaching.
