Studies on the characterisation of Biosealant properties of Bacillus sphaericus

摘要

In previous works Bacillus pasteurii was the only well known species used to precipitate the calcium carbonate. Bacillus spharecius was yet another partially characterized species with similar entity, having the capability of precipitating calcium carbonate. Earlier researchers have shown very less implementation of the organism in remediation aspect. Bacillus spharecius was sub cultured and temperature, pH were optimized at 7.4 and 37°C. Growth curve for Bacillus spharecius showed that the log phase was between 4-11 hours and after 21 hours the bacterial growth was inhibited. EDTA titration was performed to find out the amount of CaCO3 precipitate and it was highest at pH 8. The broth culture was subjected to Atomic Force Microscope studies. The analysis confirmed the presence of calcite in both the bacterial solution and dry scrapes. Optimum nickel ion concentration for calcium carbonate precipitation was found to be 80μm. The cubes were treated for 5 days in laboratory scale and to pilot scale in the second phase for 25 days. At the end of the study, the potential of Bacillus pasteurii in Bio-concrete was well established.