Comprehensive Profiling of Microbiologically Induced CaCO<sub>3</sub> Precipitation by Ureolytic <i>Bacillus</i> Isolates from Alkaline Soils

Microbiologically induced CaCO<sub>3</sub> precipitation (MICP) is a well-known bio-based solution with application in environmental, geotechnical, and civil engineering. The significance of the MICP has increased explorations of process efficiency and specificity via natural bacterial i...

Full description

Bibliographic Details
Main Authors: Olja Šovljanski, Lato Pezo, Jovana Stanojev, Branimir Bajac, Sabina Kovač, Elvira Tóth, Ivan Ristić, Ana Tomić, Aleksandra Ranitović, Dragoljub Cvetković, Siniša Markov
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Microorganisms
Subjects:
Online Access:https://www.mdpi.com/2076-2607/9/8/1691
Description
Summary:Microbiologically induced CaCO<sub>3</sub> precipitation (MICP) is a well-known bio-based solution with application in environmental, geotechnical, and civil engineering. The significance of the MICP has increased explorations of process efficiency and specificity via natural bacterial isolates. In this study, comprehensive profiling of five soil ureolytic <i>Bacillus</i> strains was performed through a newly formed procedure that involved six steps from selection and identification, through kinetic study, to the characterization of the obtained precipitates, for the first time. To shorten the whole selection procedure of 43 bioagents with the MICP potential, Standard Score Analysis was performed and five selected bacteria were identified as <i>Bacillus muralis</i>, <i>B. lentus</i>, <i>B. simplex</i>, <i>B. firmus</i>, and <i>B. licheniformis</i> by the MALDI-TOF mass spectrometry. Despite following the targeted activity, kinetic studies were included important aspects of ureolysis and the MICP such as cell concentration, pH profiling, and reduction in calcium ion concentration. At the final step, characterization of the obtained precipitates was performed using FTIR, XRD, Raman, DTA/TGA, and SEM analysis. Although all tested strains showed significant potential in terms of precipitation of calcite or calcite and vaterite phase, the main differences in the MICP behavior can be observed at the bacterial strain level. <i>B. licheniformis</i> showed favorable behavior compared to the reference <i>Sporosarcina pasteurii</i> DSM 33.
ISSN:2076-2607