Silica Solubilization Potential of Certain Bacterial Species in the Presence of Different Silicate Minerals

Silicate solubilisng bacteria (SSB) are distributed in soil, water, aquatic sediments and in silicate minerals but their population is smaller than the total bacteria indicating their uniqueness. Pond sediment showed a higher SSB with 40x10(4) g(-1) while sugarcane field soil recorded 31x10(4) g(-1) dry weight. SSB population in silicate minerals varied with the highest in phyto-sil followed by muscovite but very low in quartz and illite. The silicate solubilisation potential of the six isolates tested on eight minerals varied with the isolates and mineral. Magnesium trisilicate was more easily solubilised than, quartz, or muscovite. Four of the elite isolates were characterized by 16S r RNA sequencing and were found to be Bacillus flexus, B. mucilaginosus, B. megaterium and Pseudomonas fluorescens. The GC/MS analysis of organic acids produced in the medium containing feldspar and quartz by Bacillus flexus and B. muicilaginosus showed variation with the minerals. The release of silica in solution serves as a nutrient for life forms.