Enzyme-Induced Carbonate Precipitation (EICP)

Enzyme-induced carbonate precipitation (EICP) is a cell-free variant of Microbially Induced Calcite Precipitation (MICP). Instead of introducing whole ureolytic bacteria into the medium, EICP supplies the enzyme urease directly, together with urea and a calcium source. The same Ureolysis-Driven Carbonate Precipitation chemistry then drives calcite formation.

How it differs from MICP

• No living organisms. EICP does not require maintaining, growing or transporting bacterial cultures, and it does not depend on cells surviving in the target medium.
• Smaller treatment molecules. Free urease can penetrate finer pore spaces than bacterial cells, which may allow treatment of finer-grained soils.
• No biological by-product load. Because there are no cells, there is no organic biomass to manage, though ammonia is still released by ureolysis.
• Cost profile. Enzyme production and purification costs differ from bacterial culture costs; the trade-off depends on scale and application.

Shared constraints

EICP shares MICP's principal practical difficulties: achieving uniform distribution of the treatment through a soil volume, managing the ammonia by-product of ureolysis, and verifying performance by measurement rather than by mechanism.

Evidence status in this wiki

This page describes EICP as it is generally understood in the published literature. The source dossier that prompted the MICP pages — Microbially Induced Calcite Precipitation: The source archive Materials Dossier (Provisional Record) — does not discuss EICP; its contents cover MICP, Sporosarcina pasteurii, biocementation patents and a commercial biocementation company. No claims from it are attributed here.

Related

• Microbially Induced Calcite Precipitation (MICP) — the cell-based process.
• Ureolysis-Driven Carbonate Precipitation — the shared biochemical route.
• Bio-Cementation — the engineering applications.
• Calcium Carbonate (Calcite, CaCO₃) — the precipitated mineral.