TY - JOUR
T1 - Microbially induced calcium carbonate precipitation in fossil consolidation treatments :
T2 - Preliminary results inducing exogenous Myxococcus xanthus bacteria in a miocene Cheirogaster richardi specimen
AU - Marín-Ortega, Silvia
AU - Calvo Torras, Ma. de los Ángeles
AU - Iglesias-Campos, Manuel Ángel
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2023/7
Y1 - 2023/7
N2 - 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, Myxococcus xanthus inoculation on carbonate fossils was studied in this research. Treatment was tested on nine fossil samples from decontextualized fragments of Cheirogaster richardi specimens (Can Mata site, Hostalets de Pierola, Catalonia, Spain). The main objective was to evaluate whether treatment with Myxococcus xanthus 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 Myxococcus xanthus 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.
AB - 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, Myxococcus xanthus inoculation on carbonate fossils was studied in this research. Treatment was tested on nine fossil samples from decontextualized fragments of Cheirogaster richardi specimens (Can Mata site, Hostalets de Pierola, Catalonia, Spain). The main objective was to evaluate whether treatment with Myxococcus xanthus 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 Myxococcus xanthus 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.
KW - Microbially induced calcium carbonate precipitation
KW - Conservation
KW - Fossil
KW - Myxococcus xanthus
KW - Paleontological heritage
KW - Bioconsolidation
UR - http://www.scopus.com/inward/record.url?scp=85163568076&partnerID=8YFLogxK
U2 - 10.1016/j.heliyon.2023.e17597
DO - 10.1016/j.heliyon.2023.e17597
M3 - Article
C2 - 37449105
SN - 2405-8440
VL - 9
SP - e17597
JO - Heliyon
JF - Heliyon
IS - 7
M1 - e17597
ER -