In-depth profiling of calcite precipitation by environmental bacteria reveals fundamental mechanistic differences with relevance to application

Bianca Reeksting, Kevin Paine, Susanne Gebhard

Research output: Contribution to conferenceAbstract

Abstract

Microbially-induced calcite precipitation (MICP) is ubiquitous in nature and has become an area of interest for environmental, geotechnical, and civil engineering applications. These include bioremediation, soil engineering, and self-healing of cementitious materials. To date, ureolytic bacteria have been favoured due to their ability to rapidly increase the pH of the environment through the hydrolysis of urea and thereby induce precipitation of calcite. However, the requirement for urea can contribute to nitrogen-loading in the environment and prove to be incompatible in certain applications, such as in self-healing concrete where it delays setting. Non-ureolytic bacteria are thought to be less efficient at MICP as they lack the ability to hydrolyze urea and thus to induce rapid increases in pH. Profiling of environmental bacteria has revealed the fundamentally different mechanisms that ureolytic and non-ureolytic bacteria utilize to precipitate calcite. These affect the timing of MICP and morphology of the crystals, but not necessarily the overall quantity of calcite precipitated. Furthermore, we show that MICP facilitated by non-ureolytic bacteria results in precipitates that contain significant organic components. These precipitates appear to have increased volume and cohesiveness, which may prove advantageous in application. Our findings offer important new insights into the use of MICP for geotechnical and environmental engineering and will enable us to create a toolbox of microbial precipitators tailored for specific applications.

Original languageEnglish
Number of pages1
DOIs
Publication statusE-pub ahead of print - 8 Apr 2019
EventMicrobiology Society Annual Conference 2019 - ICC Belfast, Belfast, UK United Kingdom
Duration: 8 Apr 201911 Apr 2019
https://microbiologysociety.org/event/annual-conference/annual-conference.html

Conference

ConferenceMicrobiology Society Annual Conference 2019
Country/TerritoryUK United Kingdom
CityBelfast
Period8/04/1911/04/19
Internet address

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