Isolation Of Siderophore Producting And Mineral Dissoluting Bacteria And The Interaction Between Mica Minerals And Bacterias

The interaction of microorganism-mineral-plant system affects the dissolution of mine and formation of soil.With the further research, it was discovered that microorganisms played an important role in rock weathering and formation of soil. In this study, we investigate on the interaction of siderophore producing bacteria and mica minerals, especially the effect of bacterial siderophores on the mineral weathering and forming.Two siderophore producting bacteria Z6 and Z41 were isolated from the rhizosphere soil of advantage wild plants sheep sorrel(Rumex acetosa L.) and identified as Pseudomonas spp. based on the physiological and biochemical characteristics and 16S rDNA gene sequence analysis.Both of the strains can produce pyoverdins(a type of siderophore),and the output can achieve+++++. We had isolated and purificated the siderophores of Z6 and Z41 by gel sepaartion, amaino acid analysis.The results show that Z6 pyoverdin mainly was composed by threonine, serine, glutamic acid, glycine, lysine, and the proportion is close to 1:3:2:2:5; the Z41 pyoverdin was mainly composed by threonine, serine, glutamic acid, glycine, alanine, phenylalanine, lysine, and the proportion is close to 1:5:2:3:1:0.68:6.The optimum temperature range for growth of strains Z6 and Z41 was 25-30℃. The optimum pH range of growth was 7.0-9.0. Strains Z6 and Z41 were resistant to ampicillin, kanamycin, rifampicin, spectinomysin and heavy metals such as Pb, Cd, Cu, Zn.This study on the interaction between bacteria and minerals show that strains Z6 and Z41 can liberate silicon in two kinds of mica minerals, white mica and biotite; the biotite with high iron contention can promote bacterial biomass increasing, the minerals can promote the secretion of pyoverdins and organic acids. The addition of of organic acid and pyoverdins produced by strain Z6 and Z41 triggered fast dissolution of silicon and iron from white mica and biotite, but mineral dissolution was faster induced by pyoverdins in the presence of low molecular weight organic acids than by the organic acid or pyoverdins alone.