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 improvement of microbial characterization has increased the comprehension of microbial population and their ability in the microbiological metal dissolution. Bioleaching processes have been expanded to use microor...The improvement of microbial characterization has increased the comprehension of microbial population and their ability in the microbiological metal dissolution. Bioleaching processes have been expanded to use microorganisms for the recovery of metals from ores and wastes. This study introduces Palca mine tailings pond in Peru which turned into acid mine drainage (AMD). AMD is a source of microbial communities whose microorganisms may support the aqueous extractive metallurgy for metal recovery. Four samples of AMD were collected from different locations and the elemental characterization showed concentrations of metals, such as Cu, Zn, Al, Mn, and Fe. The pH of the samples showed variation between 1.9 - 6.8. Twenty-one microorganisms were isolated and selected according the cell morphology. 16s rRNA gene sequences identified five species of which three belong to the bacterial kingdom and two to the Fungi kingdom. Two of the bacterial species were ferrous ion oxidizing bacteria, identified as Acidithiobacillus ferriphilus and Acidithiobacillus ferridurans;and the other one a ferric ion reducing bacteria identified as Acidiphilium acidophilum. The fungi species identified were Rhodotorula sinensis and Exophiala xenobiotica, a filamentous fungus isolated for the first time from an AMD.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
Microbes are believed to play important roles in ecosystem function in many environments.The hot springs of Xiamen Island are close to the Xiamen Sea,and may have some characteristics different from those of inland ho...Microbes are believed to play important roles in ecosystem function in many environments.The hot springs of Xiamen Island are close to the Xiamen Sea,and may have some characteristics different from those of inland hot springs.Microbes living in the hot springs of Xiamen may have new characteristics.However,little is known about microbial communities of hot springs close to the Xiamen Sea.A culture-dependent survey of microbial population in the Xiamen hot springs was performed by using an approach combining total cellular protein profile identification and 16S rRNA gene sequencing.A total of 328 isolates of bacteria were obtained from liquid and sediment samples from the Xiamen hot springs,including neutrophilic thermophilic bacteria and moderately thermophilic acidophiles.Neutrophilic thermophilic bacteria,which grow at a temperature range of 55-90℃ including Rhodothermus marinus(Strain 1),Thermus thermophilus(Strain 2),Thermus thiopara(Strain 3),Geobacillus stearothermophilus(Strain 4),Geobacillus thermoleovorans(Strain 5),and Pseudomonas pseudoalcaligenes(Strain 6),were recovered by 2216E plates.Moderately thermophilic acidophiles,which can grow at temperatures above 50℃ and a pH range of 1.8-3.5 such as Alicyclobacillus acidoterrestris(Strain 8),Sulfobacillus acidophilus(Strain 9),and Sulfobacillus thermosulfidooxidans(Strain 10),were isolated on selective solid medium containing sulfur and Fe2+.Among these strains,Rhodothermus marinus,Thermus thermophilus and Geobacillus stearothermophilus are not only thermophiles,but also halophiles.One bacterium strain(Strain 6) shared 99% nucleotide sequence homology with Pseudomonas pseudoalcaligenes on the 16S rRNA gene sequence,but was quite different from Pseudomonas pseudoalcaligenes in biological characteristics,suggesting that it may represent a novel thermophilic species.Results indicated that various species of neutrophilic thermophiles and moderately thermophilic acidophiles were widely distributed in the Xiamen hot springs and that Rhodothermus marinus and Thermus thermophilus dominated the cultivable microbial community.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
The aim of this research was to convert potato peel waste (PPW) to single cell protein (SCP), and to extract valuable phenolic compounds from the spent medium. PPW is an abundant by-product of potato processing indust...The aim of this research was to convert potato peel waste (PPW) to single cell protein (SCP), and to extract valuable phenolic compounds from the spent medium. PPW is an abundant by-product of potato processing industry, consisting mostly of starch, fibre and protein in a form of watery sludge. The PPW from a chip manufacturing plant was pre-treated with sulphuric acid, and used as a substrate for an acidophilic Scytalidium acidophilum fungus under non-aseptic conditions. The produced SCP had a promising amino acid composition to be used in animal feed. Phenolic compounds were not recovered from the spent medium, most likely due to the low pH in the medium. The present findings suggest that PPW is a suitable raw material for acidophilic SCP production, whilst the extraction of phenolic acids would require milder cultivation conditions or separation before pre-treatments of SCP production. The BOD5 of the PPW was reduced by in 98% due to fungal cultivation. Thus the feed production also served as an efficient means for reduction of organic load in the PPW.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.
文摘The improvement of microbial characterization has increased the comprehension of microbial population and their ability in the microbiological metal dissolution. Bioleaching processes have been expanded to use microorganisms for the recovery of metals from ores and wastes. This study introduces Palca mine tailings pond in Peru which turned into acid mine drainage (AMD). AMD is a source of microbial communities whose microorganisms may support the aqueous extractive metallurgy for metal recovery. Four samples of AMD were collected from different locations and the elemental characterization showed concentrations of metals, such as Cu, Zn, Al, Mn, and Fe. The pH of the samples showed variation between 1.9 - 6.8. Twenty-one microorganisms were isolated and selected according the cell morphology. 16s rRNA gene sequences identified five species of which three belong to the bacterial kingdom and two to the Fungi kingdom. Two of the bacterial species were ferrous ion oxidizing bacteria, identified as Acidithiobacillus ferriphilus and Acidithiobacillus ferridurans;and the other one a ferric ion reducing bacteria identified as Acidiphilium acidophilum. The fungi species identified were Rhodotorula sinensis and Exophiala xenobiotica, a filamentous fungus isolated for the first time from an AMD.
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.
基金The Scientific Research Project of Marine Public Welfare Industry of China under contract No.200805032China Ocean Mineral Resources R &D Association under contract No.DYXM-115-02-2-07the National Infrastructure of Natural Resources for Science and Technology Program of China under contract No.2005DKA21209
文摘Microbes are believed to play important roles in ecosystem function in many environments.The hot springs of Xiamen Island are close to the Xiamen Sea,and may have some characteristics different from those of inland hot springs.Microbes living in the hot springs of Xiamen may have new characteristics.However,little is known about microbial communities of hot springs close to the Xiamen Sea.A culture-dependent survey of microbial population in the Xiamen hot springs was performed by using an approach combining total cellular protein profile identification and 16S rRNA gene sequencing.A total of 328 isolates of bacteria were obtained from liquid and sediment samples from the Xiamen hot springs,including neutrophilic thermophilic bacteria and moderately thermophilic acidophiles.Neutrophilic thermophilic bacteria,which grow at a temperature range of 55-90℃ including Rhodothermus marinus(Strain 1),Thermus thermophilus(Strain 2),Thermus thiopara(Strain 3),Geobacillus stearothermophilus(Strain 4),Geobacillus thermoleovorans(Strain 5),and Pseudomonas pseudoalcaligenes(Strain 6),were recovered by 2216E plates.Moderately thermophilic acidophiles,which can grow at temperatures above 50℃ and a pH range of 1.8-3.5 such as Alicyclobacillus acidoterrestris(Strain 8),Sulfobacillus acidophilus(Strain 9),and Sulfobacillus thermosulfidooxidans(Strain 10),were isolated on selective solid medium containing sulfur and Fe2+.Among these strains,Rhodothermus marinus,Thermus thermophilus and Geobacillus stearothermophilus are not only thermophiles,but also halophiles.One bacterium strain(Strain 6) shared 99% nucleotide sequence homology with Pseudomonas pseudoalcaligenes on the 16S rRNA gene sequence,but was quite different from Pseudomonas pseudoalcaligenes in biological characteristics,suggesting that it may represent a novel thermophilic species.Results indicated that various species of neutrophilic thermophiles and moderately thermophilic acidophiles were widely distributed in the Xiamen hot springs and that Rhodothermus marinus and Thermus thermophilus dominated the cultivable microbial community.
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the European Regional Development Fund project A70161.
文摘The aim of this research was to convert potato peel waste (PPW) to single cell protein (SCP), and to extract valuable phenolic compounds from the spent medium. PPW is an abundant by-product of potato processing industry, consisting mostly of starch, fibre and protein in a form of watery sludge. The PPW from a chip manufacturing plant was pre-treated with sulphuric acid, and used as a substrate for an acidophilic Scytalidium acidophilum fungus under non-aseptic conditions. The produced SCP had a promising amino acid composition to be used in animal feed. Phenolic compounds were not recovered from the spent medium, most likely due to the low pH in the medium. The present findings suggest that PPW is a suitable raw material for acidophilic SCP production, whilst the extraction of phenolic acids would require milder cultivation conditions or separation before pre-treatments of SCP production. The BOD5 of the PPW was reduced by in 98% due to fungal cultivation. Thus the feed production also served as an efficient means for reduction of organic load in the PPW.