A Survey Of Thermophiles From Hot Springs Close To Xiamen Sea And Identification And Characteristics Of Four Strains Of Acidithiobacillus Ferrooxidans From Different Geological Source

Microorganism in the most abundant biology resource on the earth, and thermophile and moderately thermophilic acidophiles are most important members of it. These microorganisms have developed unique enzyme systems and recovery mechanism to adapt to extreme environment, thus becoming an important biology resource for industrial use because of the special cells and enzymes. The enzymes and the biological active materials may play an important role in gene engineering, protein engineering, fermentation engineering and exploiting of mineral resources.Hot springs of Xiamen island are all close to Xiamen sea, and this may give them some traits different from those of inland hot springs and deep-sea hydrothermal vent. We collected samples from hot springs of Xiamen island near the sea, a total of 308 thermophiles and 20 moderately thermophilic acidophiles were obtained. Traditionally, taxon of bacteria usually based on the phenotype that is time-consuming. So we performed an approach combining SDS-PAGE of whole-cell protein of cultivable microbes with their 16S rRNA gene sequencing blastn. Of all these isolates, neutrophilic thermophilic bacteria including Rhodothermus marinus, Thermus thermophilus, Thermus scotoductus, Geobacillus stearothermophilus, Geobacillus thermoleovorans, Pseudomonas pseudoalcaligenes and uncultured gamma proteobacterium; moderately thermophilic acidophiles including Alicyclobacillus acidoterrestris, Sulfobacillus acidophilus and Sulfobacillus thermosulfidooxidans. All moderately thermophilic acidophiles were separated from Zhongzhou hot springs. The hot spring not only contained abundant elemental S and P, and also contained some Fe²⁺, inorganic compound and metal ions. The existence of Alicyclobacillus acidoterrestris in Zhongzhou hot spring might be involved in uncomfortable smell and environmental pollution occurred at this site. And we find some possible new strains, it can help us understand microbiology diversity in Xiamen hot springs which near the sea better. It can also provide new foundation for exploit biological resources.Acidithiobacillus ferrooxidans is a chemolithoautotrophic of Thiobacillus. It is a acidophilic bacterium, Gram-negative, obligate aerobes. This strain obtains energy and electrons for its growth mainly from the oxidation of ferrous iron (Fe²⁺) or reduced sulfur compounds. This ability makes it application in biomining to recover metal such as copper, gold, and uranium. It is one kind of the best studied bioleaching microorganisms in biohydrometallurgy. And it has a complex diversity of energy metabolic pathways, including Fe²⁺ oxidation system and sulphur oxidation system. In our research, we isolated 4 strains of A. F which came from 4 different geological sources, and then, did some comparison between these 4 strains of A. F and Acidithiobacillus ferrooxidans ATCC23270 through determine the oxidation rate of Fe²⁺, SDS-PAGE of whole-cell proteins, clone of genes, transmission electron microscope, HPLC and southern blotting. We found A. F. 2 was different with other A. F strains at the oxidation rate of Fe²⁺, composition of protein, G+Cmol% and genomic DNA. We confirm that A. F. 2 has a different Fe²⁺ oxidation system. Therefore a genomic cosmid library of A. F. 2 containing about 1500 clones with an average inserted DNA fragment above 35kb was constructed. We get Iro gene and its forward and backward sequences by colony in situ hybridizatin, and it provide abundant information for research of functional genes, related genes of electron transfer and its adaptation to the environment. Therefore, we can know better about the genomic information of Acidithiobacillus ferrooxidans and choose a new strains of A. F with a high activity and more applicative in industrial use.