The Diversity Of Magnetically Fluidized Bed Microbe Desulfurated Reactor By PCR-DGGE Method

An important problem what the government and the academia must be faced with is controlling environmental pollution .And using microbe to wipe off SO2 is a simple and efficient way to solve this problem. This way mostly depends on Sulfate-reducing bacteria (SRB) and Colourless sulfur bacteria (CSB) of the biomembrane , but in fact SRB and CSB all include lots of species .Then how many species are there on the biomembrane ? And which are the dominant species ? These are very important to really clarify the mechanism of microbe desulfurization and use the method widely.To research microbial diversity of the biomembrane, the traditional taxonomic ways can not work out.PCR-DGGE is a kind of new and efficient technic and this technic can fall together with the traditional taxonomic ways and other molecular technic such as hybridizing,cloning and sequencing, and so we can know it's composition completely. DGGE separating DNA segment depends on polyacrylamide gel electrophoresis with denaturant. It's resolving power is higher then agarose gel electrophoresis and popular polyacrylamide gel electrophoresis, and DGGE can even differentiate only one nucleotide .First total DNA was extracted by CTAB method in my research .Then the V3 region of 16S rDNA was amplified by PCR. And then DGGE bands were excised and cloned, and the positive clones were sequenced and blast in Genbank. At last phylogenetic analyse was performed.The reaserch analyzed the biomembrane in two reactors in different periods using PCR-DGGE and cloning tecnic for the first time . The results of DGGE indicated that there were five species in promotor phase and four species in running phase include loading phase and steady phase in aerobic reactor, and there were eight species in promotor phase and six species in running phase include loading phase and steady phase in anaerobic reactor. There were two dominant species both in running phase of aerobic reactor and in running phase of anaerobic reactor . Phylogenetic tree based on the 16S rDNA sequence displayed high identity above 98%. They were uncultured bacterium gene clone(BSA2B-04), Iron-reducing enrichment clone Cl-A2, Uncultured bacterium mle1-9, Uncultured bacterium clone TCc-14. In addition ,the results of sequencing of band C3-4 and band C3-5 which can be separated by DGGE were completely same. I think the reason maybe one or two base pairs have mistake in subsequent amplifying .There are about 200 bp in V3 region of 16S rDNA , so the lesser information can not become the only taxonomic basis . So other regions of 16S rDNA or the total length would be studied for the future to find more powerful results .