Study Of The Flocculation For The FlocculantProducing Train7-1 And Cloning Of DNA Flagment In The Part Of The Flocculant Gene

Bioflocculant is a kind of biological substance produced by microorgannism which has the ability of flocculating. With the properties of innocuity, high-efficiency, safe and biodegradation, it can become a new kind of products to replace chemical flocculants . though . Though with the advantages of nonpoisonous ,hurmless and non-secondary pollution ,it has not become widely used in industry because of its high cost. With the development of the gene engine , the study of the biofloculant is becoming activity . Though the biofloculant yield of some bacterium is limited, the gene of the biofloculant can be found , soon the yield will be improved.Recently, among the ways of improving the biofloculant yield, besides screening the bioflocculant-producing strains, different mutations are usually applied. In spite of the satisfying effect, the ways of mutations are too highly to control. The purpose of our project is to screen some biofloculant-product trains according to the property of all kinds of waste water,to distill the bioflocculant , analysis its component and discover its genes control the bioflocculant property.In the tests, 256 strains were isolated and purified from soil or mud collected from natural and artificial environment. Through investigating the flocculating abilities for kaolin clay of culture broth, a strain, 7-1 which had the highest flocculating activity among them, was finally picked out and was identified as Klebiella planticala.Then, the fermentation conditions and the flocculating influence factors were studied.The pure flocculant was attained by the ways of deposition, centrifugal, dialysis and vacuum. The analysis results showed that the bioflocculant was composed with expolysaccharides and with no protein. After boiling at 100 for 30 minutes, the flocculating activity seldom decreased.In the study of the heredity, four tests shows that there was no any plasmid in the 7-1. it can be deduce that its bioflocculant property was controlled by its gene. There had been a reason that the priming glycosyltransferaes is the key to synthesize expolysaccharides. Degenerate primers were designed according to the conserved regions of the priming glycosyltraferases. An DNA flagment was amplified based on PCR approach. Sequence analysis showed that it include a conserved regions of the priming glycosyltraferases. The subject is still researching now.