Shortcomings of conventional surface treatments and repair mortars for restoration/conservation purposes have directed research towards more compatible materials. Promising results of an innovative technique based on microbiologically induced carbonate precipitation (MICP) have resulted in investigations on the use of microbial based products for the building industry.

At Ghent University we have explored MICP for the deposition of a layer of calcium carbonate on limestone (i.e. biodeposition) and for the accelerated hardening of non-hydraulic lime mortars (i.e. biological lime mortars). The close collaboration between two departments, LabMET (Faculty of Bioscience-engineering, microbial aspects) and Magnel laboratory for concrete research (Faculty of Engineering and Architecture, material aspects) has resulted in two technologies that are on the verge of a commercial breakthrough, including a technology for which a patent application has been filed (WO/2010/130712).

The biodeposition treatment developed at Ghent University exhibits several advantages over similar technologies described in literature and the commercialized Calcite Bioconcept technique. Because of the metabolic pathway chosen (i.e. hydrolysis of urea), we are able to obtain a much higher performance in a shorter period of time. Furthermore, our technique enables us to perform the treatment at lower costs: a performance similar to that of Calcite Bioconcept can be obtained at ½ of their product price and ¼ of their application cost price (i.e. manhours required for application). Currently, we have demonstrated the technical proof-of-principle and have optimized the application procedure in laboratory conditions. The goal of this proposal is to demonstrate the industrial proofof- concept. In order to achieve this goal, the performance of the technology needs to be evaluated in situ. With this project, we also aim to have the in situ performance evaluated by an independent third party. Contacts with producers and distributors of surface treatments learned us that this approach is indispensable for a successful introduction into the market.

The research at Ghent University on MICP for the accelerated hardening of lime mortars has resulted in a patent application. The technique, however, has only been demonstrated as a proof-ofprinciple. With this project we will demonstrate the technical proof-of-concept and prepare a ready to use product. For that purpose, we will evaluate the early age behaviour of the mortar and optimize the composition according to the criteria set by industry (i.e. suggestions of a Belgian lime producer that will be responsible for distribution of the product). This project will be used to convince them of the short and long term benefits of our product, a key for succesful valorization of this technology.

The final goal of this project is the startup of a non venture capitalist funded spin-off company. Because of the prominent use of limestone and lime mortars in European cultural heritage, there exists a large market potential for both products that will be produced by the spin-off. Benchmarking of our products, indicating the superior performance over existing products or solutions is considered to be the go/no go milestone of the first phase of the project. The ultimate deliverable is ready to use products that can be produced at industrial scale and at reasonable prices.