Precipitation of Magnetic Iron Oxide Induced by Sporosarcina pasteurii Cells

Abstract

Sporosarcina pasteurii (S. pasteurii) is bacterium notable for its highly efficient urea degradation ability. Due to its high urease activity, S. pasteurii has been successfully utilized in applications including solidifying soil or sand, termed “bio-concrete”. In addition to calcium carbonate precipitation, urease isolated from the jack bean plant was recently demonstrated to induce the formation of magnetic iron oxide particles from soluble ferrous ion in a designed reaction. However, it remained unknown if a similar magnetic material could be formed using whole cells with high urease activity under biocompatible conditions. Here, we demonstrated that magnetic iron oxide with a highly ordered structure could be formed on the surface of S. pasteurii cells with a theoretical product of 1.17 mg in a 2-mL reaction. Moreover, the cells surrounded by the precipitated magnetic iron oxide maintained their viability. Due to the simple cultivation of S. pasteurii, the process developed in this study could be useful for the green synthesis of magnetic iron oxide, basic research on the mechanism of magnetic microbial-induced precipitation (MIP), and related engineering applications.

Polypeptide additives for improving the performance of microbially induced calcite precipitation (MICP) sand consolidation

“…Acid washing was used to determine calcium carbonate content. The calcium carbonate content was determined using an acid washing method [29]. To determine the calcium carbonate content, approximately 15 grams of uncrushed sand blocks were weighed and soaked in 0.2 M hydrochloric acid until no bubbles were observed.…”

“…The Sporosarcina pasteurii, a non-pathogenic bacterium easily obtained from soil, is the most used for sand fixation [27,28]. It boasts exceptional environmental adaptability and significant urease activity [29,30]. Calcium carbonate is produced by combining these cultured bacteria with added Ca 2+ .…”