Comparison of Single Bacterial Strain Versus Multi-Bacterial Strains on MICP

Abstract

In recent times, microbially induced calcite precipitation (MICP) is a progressively developed approach, which has the potential for sustainable and eco-friendly ground improvement. The bio-augmentation injection of bacterial strain in the soil acts as a catalyst when it comes in contact with urea and calcium chloride sources. Multiple bacteria existence effects are still not fully investigated. The study aims to examine the effect of metabolic activity of single bacteria strain Sporosarcina pasteurii (SPP) or Bacillus sphaericus (BAS) versus multi-bacterial strain (Co-culture of SPP and BAS) on uniform graded sand’s biocementation. After bio-augmentation, sand was treated in similar conditions for comparative analysis. The concentration of cementation solution (basically a urea and calcium source) was used at 0.5 M, and the treatment was extended up to 18 days keeping the injection frequency of cementation solution at 12 hrs. Biocemented samples were examined for calcite content and ultrasonic pulse velocity (UPV). The results showed significant and effective precipitation of calcite in single and multi-bacterial augmented conditions. The observation showed that the mixed bacterial strains are more robust to environmental conditions with higher growth rates because of the existence of the specific behavior of both SPP and BAS strains. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.