Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact betwe...Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.展开更多
Abstract The Fule Pb-Zn deposit is located in the Sichuan-Yunnan-Guizhou Province, and it is an important and giant low temperature metallogenic domain in China. In our research area, the Pb-Zn deposits are mainly hos...Abstract The Fule Pb-Zn deposit is located in the Sichuan-Yunnan-Guizhou Province, and it is an important and giant low temperature metallogenic domain in China. In our research area, the Pb-Zn deposits are mainly hosted in the Permian Yangxin Formation and are composed of dolostone and limestone. The distance between the ore bodies and the Permian Emeishan basalt ranged from 50 to 160 m. In this study, the nickel rich minerals, including vaesite, polydymite and millerite, were reported for the first time in the Fule deposit. These minerals occurred as xenomorphic mineral aggregate and were sporadically distributed in the sphalerite-galena-calcite vein, which is the main ore type in the deposit. Our study indicated that the paragenetic sequence of minerals in the Fule deposit is the following order： polydymite → vaesite → mil- lerite → sphalerite → galena → tetrahedrite （tennantite）. The geological occurrence characteristics of those nicke- liferous minerals suggested that the Permian Emeishan basalt is a possible barrier layer of Pb-Zn ore-forming fluid, and it is an important source for the Ni and part of the Cu in the deposit. The Sichuan-Yunnan-Guizhou Pb-Zn mineralization province is a world-class production base of Pb and Zn, in which the Permian Emeishan basalt and Pb- Zn deposits have uniformly spatial distribution, but the relationship of mineralization between them is still under debate. This report provides new evidence for understanding the relationship between Pb-Zn mineral- ization and Permian Emeishan basalt in the Sichuan- Yunnan-Guizhou Pb-Zn mineralization province.展开更多
A modified glass bead compartment cultivation system was used tocompare some chemical and biolog- ical properties of the twoarbuscular mycorrhizal (AM) fungi Glmomus mosseae and Glomusversiforme using maize (Zea mays)...A modified glass bead compartment cultivation system was used tocompare some chemical and biolog- ical properties of the twoarbuscular mycorrhizal (AM) fungi Glmomus mosseae and Glomusversiforme using maize (Zea mays) as the host plant with four addedlevels of available phosphorus (P). The proportion of host plant rootlength infected was determined t harvest. Shoot and root yields andnutrient concentra- tions were determined, together with the nutrientconcentrations in the AM fungal external mycelium. The morphology ofvarious mycorrhizal structures of the two AM fungi was also comparedby microscopic obser- vation.展开更多
Based on optimized forecast method of unascertained classifying,a unascer- tained measurement classifying model (UMC) to predict mining induced goaf collapse was established,The discriminated factors of the model are ...Based on optimized forecast method of unascertained classifying,a unascer- tained measurement classifying model (UMC) to predict mining induced goaf collapse was established,The discriminated factors of the model are influential factors including over- burden layer type,overburden layer thickness,the complex degree of geologic structure, the inclination angle of coal bed,volume rate of the cavity region,the vertical goaf depth from the surface and space superposition layer of the goaf region.Unascertained mea- surement (UM) function of each factor was calculated.The unascertained measurement to indicate the classification center and the grade of waiting forecast sample was determined by the UM distance between the synthesis index of waiting forecast samples and index of every classification.The training samples were tested by the established model,and the correct rate is 100%.Furthermore,the seven waiting forecast samples were predicted by the UMC model.The results show that the forecast results are fully consistent with the ac- tual situation.展开更多
文摘Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.
基金supported by the National ‘973 Project’(No.2014CB440900)the State Key Program of National Natural Science Foundation of China(No.41430315)the National Natural Science Foundation of China(Grant No.41173063)
文摘Abstract The Fule Pb-Zn deposit is located in the Sichuan-Yunnan-Guizhou Province, and it is an important and giant low temperature metallogenic domain in China. In our research area, the Pb-Zn deposits are mainly hosted in the Permian Yangxin Formation and are composed of dolostone and limestone. The distance between the ore bodies and the Permian Emeishan basalt ranged from 50 to 160 m. In this study, the nickel rich minerals, including vaesite, polydymite and millerite, were reported for the first time in the Fule deposit. These minerals occurred as xenomorphic mineral aggregate and were sporadically distributed in the sphalerite-galena-calcite vein, which is the main ore type in the deposit. Our study indicated that the paragenetic sequence of minerals in the Fule deposit is the following order： polydymite → vaesite → mil- lerite → sphalerite → galena → tetrahedrite （tennantite）. The geological occurrence characteristics of those nicke- liferous minerals suggested that the Permian Emeishan basalt is a possible barrier layer of Pb-Zn ore-forming fluid, and it is an important source for the Ni and part of the Cu in the deposit. The Sichuan-Yunnan-Guizhou Pb-Zn mineralization province is a world-class production base of Pb and Zn, in which the Permian Emeishan basalt and Pb- Zn deposits have uniformly spatial distribution, but the relationship of mineralization between them is still under debate. This report provides new evidence for understanding the relationship between Pb-Zn mineral- ization and Permian Emeishan basalt in the Sichuan- Yunnan-Guizhou Pb-Zn mineralization province.
基金National Key Basic Research Support Foundation(NKBRSF)of China(No.G1999011807) the Joint Open Laboratory of Soil and Environment between the Institute of Soil Science of the Chinese Academy ot Sciences and Hong Kong Baptist University. 2Corresp
文摘A modified glass bead compartment cultivation system was used tocompare some chemical and biolog- ical properties of the twoarbuscular mycorrhizal (AM) fungi Glmomus mosseae and Glomusversiforme using maize (Zea mays) as the host plant with four addedlevels of available phosphorus (P). The proportion of host plant rootlength infected was determined t harvest. Shoot and root yields andnutrient concentra- tions were determined, together with the nutrientconcentrations in the AM fungal external mycelium. The morphology ofvarious mycorrhizal structures of the two AM fungi was also comparedby microscopic obser- vation.
基金the National Natural Science Foundation of China(50490274)Mittal Innovative and Enterprising Project at Center South University(07MX14)
文摘Based on optimized forecast method of unascertained classifying,a unascer- tained measurement classifying model (UMC) to predict mining induced goaf collapse was established,The discriminated factors of the model are influential factors including over- burden layer type,overburden layer thickness,the complex degree of geologic structure, the inclination angle of coal bed,volume rate of the cavity region,the vertical goaf depth from the surface and space superposition layer of the goaf region.Unascertained mea- surement (UM) function of each factor was calculated.The unascertained measurement to indicate the classification center and the grade of waiting forecast sample was determined by the UM distance between the synthesis index of waiting forecast samples and index of every classification.The training samples were tested by the established model,and the correct rate is 100%.Furthermore,the seven waiting forecast samples were predicted by the UMC model.The results show that the forecast results are fully consistent with the ac- tual situation.
