By analyzing the shift of microbial communities under different iron/sulfur ratios, the response of metallurgical microorganisms to energy substrates was investigated based on molecular ecological networks. High-throughput sequencing of microbial samples from different domesticated batches was conducted to analyze the changes in community composition, alpha and beta diversity. Based on the molecular ecological network, the interactions between microorganisms under different iron/sulfur ratios were explored. Keystones were identified to analyze the community response to energy substrates. In the process of domestication based on different energy substrates, the dominant species in the in iron-rich and sulfur-less community were Acidithiobacillus ferrooxidans and A. ferriphilus. A. thiooxidans accounted for up to 90% in the sulfur-rich and iron-less community after 3 domesticating batches. The results of alpha and beta diversity analysis show that the domestication process of sulfur-rich and iron-less substrates reduced the diversity of microbial communities. Molecular ecological network analysis shows that the keystones were all rare species with low abundance. During the domestication by sulfur-rich and iron-less energy substrates, the bacterial species had a closer symbiotic relationship and the community was more stable. Through this domestication experiment, the impact of different energy substrates on microbial aggregation was clarified. Domesticating metallurgical microorganisms by using sulfur-rich and iron-less energy substrates made the microbial colonies to be more stable, which was conducive to the oxidation of iron and sulfur, promoting the dissolution of sulfide minerals. Our findings provide a reference for the directional domestication of metallurgical microorganisms.
Acidithiobacillus/genetics* ; Iron ; Minerals ; Oxidation-Reduction ; Sulfur

A magnetic separator was used to separate magnetic bacteria based on their magnetotactic characteristics. Acidithiobacillus ferrooxidans, a bacterium that could synthesize intra-cellular nanometer magnetic particles, was investigated as an example. Strong magnetic and weak magnetic cells were separated and collected. On average, the number of the magnetic particles present in the strong magnetic cells is more than that of the weak magnetic cells. Moreover, semisolid-plate magnetophoresis showed that the magnetotaxis of strong magnetic cells was stronger than the weak magnetic cells. These results suggest that the magnetic separator can be used to isolate the magnetic bacteria, which will facilitate the research of magnetic bacteria.
Acidithiobacillus ; isolation & purification ; metabolism ; Bacteria ; isolation & purification ; metabolism ; Bacterial Physiological Phenomena ; Bacteriological Techniques ; methods ; Magnetics

Biohydrometallergy technology received more and more attention because of its simple process, low cost and kind to environment, especially in dealing with low-grade and complex minerals. However, it is difficult to optimize microorganism species and process parameters in bioleaching procedure because of the lack of suitable bacteria and quantitative analysis methods at micro-level for bioleaching system. This has resulted in the low efficiency and poor yield of the target metal in bioleaching. With the development of microarray and bacteria conservation technology, solutions to the above problems were being found. This article summarizes the latest findings on genetic elucidation and the community structure of microorganisms in sulfide minerals bioleaching system, in the aim of providing a better understanding on the significance of cross-field technology of biohydrometallergy and genomics.
Acidithiobacillus ; genetics ; isolation & purification ; metabolism ; Industrial Microbiology ; methods ; trends ; Microarray Analysis ; Minerals ; metabolism ; Mining ; methods ; Sulfides ; chemistry ; metabolism

Acidithiobacillus ferrooxidans is able to synthesize intra-cellular electron-dense magnetite, which formed by BCM method in Acidithiobacillus ferrooxidans. The whole genome of the type strain Acidithiobacillus ferrooxidans ATCC 23270 was analyzed by bioinformatics and some homolog genes of functional ones in magnetotactic bacteria were available. This study analyzed the different concentration of Fe2+ stress response of mpsA, magA, thy and mamB gene by using real-time PCR analysis. Temporal genes expression profiles were examined in cells subjected to different concentration of FeSO4 x 7H2O stress, they reached to high expression under 150-200 mmol/L FeSO4 x 7H2O stress. With this new method study, it is possible that we could do deeper research to generate a comprehensive description of the mechanism that how Acidithiobacillus ferrooxidans synthesize the magnetic particles.
Acidithiobacillus ; genetics ; metabolism ; Amino Acid Sequence ; Bacterial Proteins ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Ferrous Compounds ; pharmacology ; Gene Expression Profiling ; Genes, Bacterial ; Magnetics ; Molecular Sequence Data ; Stress, Physiological ; Sulfur ; metabolism