Metabolic Insights Into Microbially Induced Calcite Formation by Bacillaceae for Application in Bio-Based...

Area of Science:

• Biomineralization
• Microbial biotechnology
• Sustainable materials science

Background:

• Microbially induced calcite precipitation (MICP) is key for sustainable infrastructure materials.
• Ureolytic MICP is well-understood, but non-ureolytic pathways remain unclear, limiting applications.
• Non-ureolytic MICP avoids ammonia release, a significant environmental and safety benefit.

Purpose of the Study:

• To investigate the link between carbon source utilization and non-ureolytic MICP.
• To identify specific carbon sources that can drive MICP in environmental bacteria.
• To elucidate the physiological mechanisms underlying non-ureolytic MICP in Bacillaceae.

Main Methods:

• Culturing of environmental Bacillaceae isolates with various carbon sources.
• Acetate utilization and calcium precipitation quantification.
• Genome sequencing and gene expression analysis of Solibacillus silvestris.
• Development of a genetic system for gene deletion studies.

Main Results:

• Acetate was identified as a carbon source driving non-ureolytic MICP in several Bacillaceae.
• Solibacillus silvestris demonstrated high efficiency in calcium precipitation using acetate, independent of active growth.
• Gene expression analysis suggested a link between acetate catabolism and MICP, potentially as a calcium stress response.
• Deletion of a putative calcium-binding protein had minimal impact on MICP.

Conclusions:

• Acetate catabolism is a viable pathway for non-ureolytic MICP.
• This finding expands the potential applications of MICP in sustainable materials.
• Further research into the physiological mechanisms can optimize biomineralization processes.