A cooperative bioleaching(Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans)and single bioleaching(Acidithiobacillus ferriooxidans or Acidithiobacillus thiooxidans)of sphalerite were investigated by X-...A cooperative bioleaching(Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans)and single bioleaching(Acidithiobacillus ferriooxidans or Acidithiobacillus thiooxidans)of sphalerite were investigated by X-ray diffractometry,energy dispersive spectrography and scanning electron microscopy.The experimental results show that the leaching rate of zinc in the mixed culture is higher than that in pure culture and the sterile control.In these processes,two kinds of bacteria perform different functions and play a cooperative role during leaching of sphalerite.The bioleaching action carried out by Acidithiobacillus ferriooxidans(A.ferriooxidans)is not directly performed through Fe2+ but Fe3+,and its role is to oxidize Fe2+ to Fe 3+ and maintain a high redox potential.Moreover,the addition of an appropriate concentration of ferric iron to the leaching systems is beneficial to zinc dissolution.In the leaching systems without Acidithiobacillus thiooxidans(A.thiooxidans),elemental sulfur layers are formed on mineral surface during the dissolution of zinc and block continuous leaching.Acidithiobacillus thiooxidans,however,eliminate the passivation and cause the bioleaching process to continue in the leaching systems.At the same time,protons from the bacterial oxidization of the elemental sulfur layers also accelerate the leaching of zinc.展开更多
An acidophilic,rod-shaped Gram-negative sulfur oxidizing strain BY-05 was isolated from an acid mine drainage of copper ore in Baiyin area,Gansu Province,China.Ultrastructural studies show that the isolate has a tuft ...An acidophilic,rod-shaped Gram-negative sulfur oxidizing strain BY-05 was isolated from an acid mine drainage of copper ore in Baiyin area,Gansu Province,China.Ultrastructural studies show that the isolate has a tuft of polar flagella and possesses sulfur granules with clear membrane adhering to the cell innermembrane.Physiological study shows that this isolate grows autotrophically and aerobically by oxidizing S0and reduced inorganic sulfur compounds(SO, 2 23-SO, 2 24- S2 -and ZnS)with the optimum growth at pH 3.5-4.0 and at the temperature range of 25-30℃.The 16S rRNA gene sequence(DQ 423683)of strain BY-05 has 100%sequence similarity to that of Acidithiobacillus albertensis(DSM 14366).So it is identified and named as A. albertensis BY-05.Bioleaching experiments with this new strain show that it can play an important role in recovery of metals from chalcopyrite and sphalerite.展开更多
基金Project(2004CB619204)supported by the National Basic Research Program of ChinaProjects(50374075,50321402)supported by the National Natural Science Foundation of China
文摘A cooperative bioleaching(Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans)and single bioleaching(Acidithiobacillus ferriooxidans or Acidithiobacillus thiooxidans)of sphalerite were investigated by X-ray diffractometry,energy dispersive spectrography and scanning electron microscopy.The experimental results show that the leaching rate of zinc in the mixed culture is higher than that in pure culture and the sterile control.In these processes,two kinds of bacteria perform different functions and play a cooperative role during leaching of sphalerite.The bioleaching action carried out by Acidithiobacillus ferriooxidans(A.ferriooxidans)is not directly performed through Fe2+ but Fe3+,and its role is to oxidize Fe2+ to Fe 3+ and maintain a high redox potential.Moreover,the addition of an appropriate concentration of ferric iron to the leaching systems is beneficial to zinc dissolution.In the leaching systems without Acidithiobacillus thiooxidans(A.thiooxidans),elemental sulfur layers are formed on mineral surface during the dissolution of zinc and block continuous leaching.Acidithiobacillus thiooxidans,however,eliminate the passivation and cause the bioleaching process to continue in the leaching systems.At the same time,protons from the bacterial oxidization of the elemental sulfur layers also accelerate the leaching of zinc.
基金Project(50321402)supported by the National Natural Science Foundation of ChinaProject(2004CB619204)supported by the NationalBasic Research Program of China
文摘An acidophilic,rod-shaped Gram-negative sulfur oxidizing strain BY-05 was isolated from an acid mine drainage of copper ore in Baiyin area,Gansu Province,China.Ultrastructural studies show that the isolate has a tuft of polar flagella and possesses sulfur granules with clear membrane adhering to the cell innermembrane.Physiological study shows that this isolate grows autotrophically and aerobically by oxidizing S0and reduced inorganic sulfur compounds(SO, 2 23-SO, 2 24- S2 -and ZnS)with the optimum growth at pH 3.5-4.0 and at the temperature range of 25-30℃.The 16S rRNA gene sequence(DQ 423683)of strain BY-05 has 100%sequence similarity to that of Acidithiobacillus albertensis(DSM 14366).So it is identified and named as A. albertensis BY-05.Bioleaching experiments with this new strain show that it can play an important role in recovery of metals from chalcopyrite and sphalerite.
