Fig. 1

Stone damage at the cloister entrance of San Jeronimo Monastery. a General overview. Detail of the stone blocks used for the bio-consolidation treatments: Myxococcus xanthus treatment (b), M-3P nutritive solution treatment (c), self-inoculation bio-treatment (d). Scanning electron microscopy (SEM) photomicrographs of corroded calcite (e), niter (KNO3) (EDS spectrum in inset) (f) and hexahydrite (MgSO4·6H2O) salt crystals (g) in the weathered calcarenite stone (EDS spectrum in inset)