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1.
Thomas R. Clark Henry L. Ehrlich 《Journal of industrial microbiology & biotechnology》1992,9(3-4):213-218
Summary Copper contained in a solid industrial waste produced in a silicone manufacturing process was leached with spent iron medium from aThiobacillus ferrooxidans culture. Most effective leaching was observed in a continuously fed, dual reactor system. Spent iron medium was generated by growingT. ferrooxidans in 0.9 K iron medium at pH 1.5 in the first reactor, and was transferred to a second reactor in which it leached the copper from the waste. Leaching was effective at a pulp density of the waste material as high as 20%. In experiments run at a pulp density of 2.5%, the spent iron medium was most efficient in leaching copper when it was first diluted 100-fold with a mineral salts solution at pH 1.5. Removal of the copper from the waste appeared to involve its displacement by acid, dissolved mineral salts, and ferric iron. Potentials for practical application of this process are discussed. 相似文献
2.
目的:为阐明微生物群落演替及功能与浸出效率之间关系奠定基础,以及如何提高黄铜矿生物浸出效率和铜回收率提供理
论依据。方法:通过连续传代培养进行驯化,使得复合菌群的矿浆浓度耐受能力达到25 %(w/v)。采用该复合菌群在25 %矿浆浓
度下浸出黄铜矿,同时利用变性梯度凝胶电泳和克隆文库技术分析浸出过程中的微生物多样性。最后,采用实时荧光定量PCR 对
浸出过程中微生物群落结构进行定量解析。结果:28天内黄铜矿浸出率能够达到95.1 %,而驯化前的浸出率只有51.5%。该复合
菌群主要由Acidithiobacillus caldus, Sulfobacillus acidophilus,和Fereoplasma theroplasma thermophilum组成,其中Acidithbacillus caldus是浸出前期和后期的优势种群,而Sulfobacillus acidophilus在浸出中期均有竞争优势, Ferroplasma thermophilum在整个浸出过程中占
据整个群落的比例均较低。结论:本研究获得的复合菌群具有较强的浸出黄铜矿能力, Acidithiobacillus caldus和Sulfobacillus acidophilus在浸出过程中起着重要的作用,pH 值和铜浸出率与群落结构相关性较高。 相似文献
3.
Novel bacterial sulfur oxygenase reductases from bioreactors treating gold-bearing concentrates 总被引:1,自引:0,他引:1
Chen ZW Liu YY Wu JF She Q Jiang CY Liu SJ 《Applied microbiology and biotechnology》2007,74(3):688-698
The microbial community and sulfur oxygenase reductases of metagenomic DNA from bioreactors treating gold-bearing concentrates
were studied by 16S rRNA library, real-time polymerase chain reaction (RT-PCR), conventional cultivation, and molecular cloning.
Results indicated that major bacterial species were belonging to the genera Acidithiobacillus, Leptospirillum, Sulfobacillus, and Sphingomonas, accounting for 6.3, 66.7, 18.8, and 8.3%, respectively; the sole archaeal species was Ferroplasma sp. (100%). Quantitative RT-PCR revealed that the 16S rRNA gene copy numbers (per gram of concentrates) of bacteria and archaea
were 4.59 × 109 and 6.68 × 105, respectively. Bacterial strains representing Acidithiobacillus, Leptospirillum, and Sulfobacillus were isolated from the bioreactors. To study sulfur oxidation in the reactors, pairs of new PCR primers were designed for
the detection of sulfur oxygenase reductase (SOR) genes. Three sor-like genes, namely, sor
Fx, sor
SA, and sor
SB were identified from metagenomic DNAs of the bioreactors. The sor
Fx is an inactivated SOR gene and is identical to the pseudo-SOR gene of Ferroplasma acidarmanus. The sor
SA and sor
SB showed no significant identity to any genes in GenBank databases. The sor
SB was cloned and expressed in Escherichia
coli, and SOR activity was determined. Quantitative RT-PCR determination of the gene densities of sor
SA and sor
SB were 1,000 times higher than archaeal 16S rRNA gene copy numbers, indicating that these genes were mostly impossible from
archaea. Furthermore, with primers specific to the sor
SB gene, this gene was PCR-amplified from the newly isolated Acidithiobacillus sp. strain SM-1. So far as we know, this is the first time to determine SOR activity originating from bacteria and to document
SOR gene in bioleaching reactors and Acidithiobacillus species. 相似文献
4.
Biomining comprises of processing and extraction of metal from their ores and concentrates using microbial techniques. Currently this is used by the mining industry to extract copper, uranium and gold from low grade ores but not for low grade manganese ore in industrial scale. The study of microbial genomes, metabolites and regulatory pathways provide novel insights to the metabolism of bioleaching microorganisms and their synergistic action during bioleaching operations. This will promote understanding of the universal regulatory responses that the biomining microbial community uses to adapt to their changing environment leading to high metal recovery. Possibility exists of findings ways to imitate the entire process during industrial manganese biomining endeavor. This paper reviews the current status of manganese biomining research operations around the world, identifies factors that drive the selection of biomining as a processing technology, describes challenges in exploiting these innovations, and concludes with a discussion of Mn biomining’s future. 相似文献
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R. Nareshkumar R. Nagendran K. Parvathi 《World journal of microbiology & biotechnology》2008,24(8):1539-1546
Bioleaching of heavy metals from contaminated soil was carried out using indigenous sulfur oxidizing bacterium Acidithiobacillus thiooxidans. Experiments were carried out by varying sulfur/soil ratio from 0.03 to 0.33 to evaluate the optimum ratio for efficient
bioleaching of heavy metals from soil. The influence of sulfur/soil ratio on the bioleaching efficiency was assessed based
on decrease in pH, increase in oxidation–reduction potential, sulfate production and solubilization of heavy metals from the
soil. Decrease in pH, increase in oxidation–reduction potential and sulfate production was found to be better with the increase
in sulfur/soil ratio. While the final pH of the system with different sulfur/soil ratio was in the range of 4.1–0.7, oxidation
reduction potential varied from 230 to 629 mV; sulfate production was in the range of 2,786–8,872 mg/l. Solubilization of
chromium, zinc, copper, lead and cadmium from the contaminated soil was in the range of 11–99%. Findings of the study will
help to optimize the ratio of sulfur/soil to achieve effective bioleaching of heavy metals from contaminated soils. 相似文献
8.
A. Senthil Kumar V. Venkatesalu K. Kannathasan M. Chandrasekaran 《Indian journal of microbiology》2010,50(1):70-75
Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda.
The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency
of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy.
It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external
has no effect on efficiency of bioleaching showing domination of direct leaching mechanism over indirect. 相似文献
9.
To understand the composition and structure of microbial communities in acid mineral bioleaching systems, the molecular diversity
of 16S rDNA genes was examined using a PCR-based cloning approach. A total of 31 Operational Taxonomic Units (OTUs) were obtained
from the four samples taken from four different bioleaching sites in Yinshan lead–zinc mine and Dongxiang copper mine in Jiangxi
Province, China. The percentages of overlapping OTUs between sites ranged from 22.2 to 50.0%. Phylogenetic analysis revealed
that the bacteria present at the four bioleaching sites fell into six divisions, α-Proteobacteria (1.1%), β-Proteobacteria (2.3%), γ-Proteobacteria (30.8%), Firmicutes (15.4%), Actinobacteria (0.3%) and Nitrospira (50.1%). Organisms of genera Leptospirillum, Acidithiobacillus, and Sulfobacillus, which were in Nitrospira, γ-Proteobacteria, and Firmicutes divisions, respectively, were the most dominant. The results of principal component analysis based on the six phylogenetic
divisions and biogeochemical data indicated that the microbial community structure of a site was directly related to the biogeochemical
characteristic of that site. It follows therefore that sites with similar biogeochemical characteristics were comprised of
similar microbial community structures. The results in our study also suggest that the elements copper and arsenic appear
to be the key factors affecting the compositions and structures of microbial community in the four bioleaching sites.
Zhiguo He, Shengmu Xiao, Xuehui Xie are equally contributed to this work. 相似文献
10.
It is well known that pulp density and particle size determine the available surface area concentration and have an influence
in the overall rate of bioleaching of minerals. As metal solubilization takes place through the surface area of the particles,
it can be expected that different combinations of pulp densities and particle sizes giving the same surface area concentration
would determine the same leaching rate. The objective of this work was to test this hypothesis on the effect of surface area
concentration, pulp density and particle size of the biooxidation of a pyritic gold concentrate by the thermophilic Archaeon
Sulfolobus metallicus in shake flasks. The gold concentrate was used at 2.5%, 5%, 10%, and 15% w/v pulp density and at four size fractions: 150–106,
106–75, 75–38 and –38 μm. Temperature was 68°C and the initial pH was 2.0. Results showed that the volumetric productivities
of iron and sulfate depend not only on the surface area concentration but also on pulp density and particle size considered
separately. These two variables not only determine surface area but also exert additional effects on the process, so the hypothesis
was not confirmed. Maximum attained iron productivity was 1.042 g/l day with the 75–38 μm fraction at 5% pulp density. Maximum
sulfate productivity was 4.279 g/l day with the 75–38 μm fraction at 10% pulp density. 相似文献