Research of Biological Desilication Mechanism by Bacillus mucilaginosus GSY

Abstract

Biological desilication by Bacillus mucilaginosus was investigated using 10 g/L of the cell suspension, fermented liquid and 100 μg/mL of polysaccharide solution. Results showed that the ratio (A/S) of Al and Si in bauxite increased from 2.84 to 3.32, 3.74, 4.19, respectively; and the effects of desilication were all significant by T test. The infrared spectra both of the cell and polysaccharides before and after leaching had significant changes at the wave number of 1070 cm-1 and there were two peaks broadened absorption after leaching, so these appear that the silicon complexes were formed by Si-O-R form. Before and after leaching of bauxite, it was observed by the scanning electron microscope, many holes were formed and the bacteria in the leaching process had significantly erosion on the bauxite surface. Otherwise XREDS analysis further proved that Bacillus mucilaginosus GSY had significant desilication effect.