Influence of native ureolytic microbial community on biocementation potential of Sporosarcina pasteurii

Raja Murugan,G K Suraishkumar,Abhijit Mukherjee,Navdeep K Dhami

doi:10.1038/s41598-021-00315-5

Abstract

Microbially induced calcium carbonate precipitation (MICP)/Biocementation has emerged as a promising technique for soil engineering applications. There are chiefly two methods by which MICP is applied for field applications including biostimulation and bioaugmentation. Although bioaugmentation strategy using efficient ureolytic biocementing culture of Sporosarcina pasteurii is widely practiced, the impact of native ureolytic microbial communities (NUMC) on CaCO3 mineralisation via S. pasteurii has not been explored. In this paper, we investigated the effect of different concentrations of NUMC on MICP kinetics and biomineral properties in the presence and absence of S. pasteurii. Kinetic analysis showed that the biocementation potential of S. pasteurii is sixfold higher than NUMC and is not significantly impacted even when the concentration of the NUMC is eight times higher. Micrographic results revealed a quick rate of CaCO3 precipitation by S. pasteurii leading to generation of smaller CaCO3 crystals (5–40 µm), while slow rate of CaCO3 precipitation by NUMC led to creation of larger CaCO3 crystals (35–100 µm). Mineralogical results showed the predominance of calcite phase in both sets. The outcome of current study is crucial for tailor-made applications of MICP.

Highlights

Induced calcium carbonate precipitation (MICP)/Biocementation has emerged as a promising technique for soil engineering applications
We investigated the influence of native ureolytic microbial communities (NUMC) on the biocementation potential of the most widely used bacterial culture S. pasteurii
We evaluated the biogenic C aCO3 precipitation kinetics of NUMC at varying concentrations in the presence and absence of S. pasteurii along with its impact on the morpho-mineralogical characteristics of the precipitated carbonates

Summary

Introduction

Induced calcium carbonate precipitation (MICP)/Biocementation has emerged as a promising technique for soil engineering applications. By altering the nutrients, substrates, and electron acceptors to enrich the native microorganisms for accelerating the C aCO3 precipitation; whereas, bioaugmentation includes the addition of highly potential ureolytic and cementing strains especially Sporosarcina pasteurii into the fields[5,32,33,34,35]. Comparing these two approaches, MICP through bioaugmentation has a major advantage as it is a rapid process. The concentration of NUMC changes vastly in the field and may affect the kinetics of the C aCO3 process, its mineralogy, and morphology which are the determining factors for the success of biocementation[22]

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