Effects Of Aspergillus Fumigatus Z5 And Oxalic Acids On Phyllosillicates

In recent years, weathering of clay minerals by microorganism is an important environmental process affecting the fertility of soils. This paper investigates the influence of microbes and small organic molecules on the structure change of clay mineral and discusses the significance of this process on the soil ecology. To some extent, it reflects the regularity of mineral soil microbial transformation and elements cycle, and provides the scientific basis for improving the quality of the soil rhizosphere environment.This paper adopted Aspergillus fumigatus Z5 filtered at our laboratory, and cultured respectively with three pollysilicate clay minerals, i.e., montmorillonite, kaolinite, and illite. Furthermore, the effect of Aspergillus fumigatus Z5 on the structure of the three kinds of clay mineral were investigated by SEM, TEM, CLSM, XRD, and other testing instrument. With montmorillonite and strain Z5 cocultivation, sampling respectively in 8 h,24 h,36 h, 48 h, researching Aspergillus fumigatus Z5 effecting on montmorillonite in the process of microbe growth. Small molecule organic acids are important microorganism metabolites, the role of microbes and minerals in physics, microorganisms extracellular protein, extracellular polysaccharide and small molecule organic acids. Through the study of small molecule organic acid and the effect of montmorillonite, thus for further study of microbes and minerals role lay a certain foundation.In the process of mineral and microbial interacting with each other, Aspergillus fumigatus Z5 effect on minerals by hyphal growth and metabolic product, decomposing large mineral grains into small mineral particles, hyphae adsorb on small mineral particles, forming around the hypha ball of mineral grains. The effect of Aspergillus fumigatus Z5 makes the layered structure of montmorillonite becoming curly, fold;the metabolic productc of Aspergillus fumigatus Z5 destory montmorillonite structure of Si-O, Al-O, replace montmorillonite interlayer element such as Ca, Mg, release metal elements in the montmorillonite Si, Al, Ca, Mg, Fe, the releasing quantity of Si and Al are the most; Aspergillus fumigatus Z5 interacting with montmorillonite makes the genesis of regularly arranged montmorillonite lattice chaotic, crystallinity variation; Aspergillus fumigatus Z5 metabolites intercalate in montmorillonite, making the montmorillonite layer spacing increasing, further promote Z5 metabolic product entering into interlayer, thus increasing dissolution.Montmorillonite also has certain influence on the growth of microorganism metabolism, after Aspergillus fumigatus Z5 and montmorillonite cocultivation, extracellular protein and extracellular polysaccharide increase significantly, lipid, cellulose is reduce, the hyphae cell of Aspergillus fumigatus Z5 survival time increase.Oxalic acid is important microbial metabolites, oxalic acid can damage morphology structure of montmorillonite, the montmorillonite layers become curly; Destroy the structure of montmorillonite in the metal valence, corrosion of metal elements in the montmorillonite; C2O42- into the montmorillonite layers with interlayer cation Ca2+ generated CaC2O4·H2O with montmorillonite intercalated effect, change the montmorillonite layer spacing.Strain Z5 closely combined with montmorillonite, formed hyphae mineral complexes, promote the role of fungi and mineral. The interaction of fungi and mineral is an amplification reaction, as reaction continues, function more and more fierce.