Biocementation potential of Sporosarcina pasteurii and Pseudomonas M47T1 for sustainable soil stabilization

¹ Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal
² CEMMPRE, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal

^* Corresponding author: amaandamendonca@hotmail.com

Abstract

This study investigates the potential of bio-inspired solutions to enhance the geomechanical properties of sandy soil through the biocementation process, using two bacterial strains: Sporosarcina pasteurii and Pseudomonas M47T1. Laboratory experiments were conducted to evaluate the ability of these bacteria to induce calcium carbonate precipitation, a key process for improving soil stability. The research design included assessment of ureolytic activity, unconfined compressive strength, and the effects of factors such as curing time on biostabilised soil. Results demonstrated that both bacterial strains were highly effective in promoting calcium carbonate precipitation, leading to significant improvements in the soil's geomechanical properties. Despite challenges posed by environmental conditions for bacterial growth, the findings showed that Sporosarcina pasteurii and Pseudomonas M47T1 performed satisfactorily, yielding stable soil structures. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) confirmed the presence of calcium carbonate (CaCO₃). The study underscores the potential of these bacterial strains as effective agents for sustainable and bio-inspired approaches to soil stabilization, introducing practical solutions for improving the mecha- nical performance of natural sandy soils.