Microbially induced calcium carbonate precipitation in fossilconsolidation treatments: Preliminary results inducing exogenous<em>Myxococcus xanthus</em> bacteria in a miocene <em>Cheirogasterrichardi</em> specimen

This research paper proposes Microbially Induced Calcium Carbonate Precipitation (MICP) as an innovative approach for palaeontological heritage conservation, specifically on deteriorated carbonate fossils. Due to its efficiency in bioconsolidation of carbonate ornamental rocks, <em>Myxococcus...

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Detalles Bibliográficos
Autores: Marín Ortega, Sílvia, Calvo Torras, Ma. de los Ángeles, Iglesias Campos, M. A. (Manuel Ángel)
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/218995
Acceso en línea:https://hdl.handle.net/2445/218995
Access Level:acceso abierto
Palabra clave:Microbiologia
Conservació i restauració
Paleontologia
Microbiology
Conservation and restoration
Paleontology
Descripción
Sumario:This research paper proposes Microbially Induced Calcium Carbonate Precipitation (MICP) as an innovative approach for palaeontological heritage conservation, specifically on deteriorated carbonate fossils. Due to its efficiency in bioconsolidation of carbonate ornamental rocks, <em>Myxococcus xanthus</em> inoculation on carbonate fossils was studied in this research.Treatment was tested on nine fossil samples from decontextualized fragments of <em>Cheirogaster richardi</em> specimens (Can Mata site, Hostalets de Pierola, Catalonia, Spain). The main objective was to evaluate whether treatment with <em>Myxococcus xanthus</em> improved fossil surface cohesion and hardness and mechanical strength without significant physicochemical and aesthetic changes to the surface. Chemical compatibility of the treatment, penetration capacity and absence of noticeable changes in substrate porosity were considered as important issues to be evaluated. Samples were analysed, before and after treatment, by scanning electron microscopy, weight control, spectrophotometry, X-ray diffraction analysis, water absorption analysis, pH and conductivity control, Vickers microindentation and tape test. Results show that hardness increases by a factor of almost two. Cohesion also increases and surface disaggregated particles are bonded together by a calcium carbonate micrometric layer with no noticeable changes in surface roughness. Colour and gloss variations are negligible, and pH, conductivity and weight hardly change. Slight changes in porosity were observed but without total pore clogging. To sum up, results indicate that <em>Myxococcus xanthus</em> biomineralisation is an effective consolidation treatment for carbonate fossils and highly compatible with carbonate substrates. Furthermore, bacterial precipitation of calcium carbonate is a safe and eco-friendly consolidation treatment.