Six bacterial strains were isolated from a damaged medieval wall painting. The isolates were characterized by a polyphasic approach, including analysis of respiratory isoprenoid quinones, polar lipids, fatty acids, polyamines, cell wall diamino acids and sugars from whole cell hydrolysates, SDS-PAGE, physiological examinations and partial 16S rDNA sequence analysis. Based on the results of these investigations, three strains were allocated to the generaBacillus, Kocuria and Agromyces. Two isolates were shown to be representatives of a new genus, distantly related to the genera Clavibacter and Rathayibacter. The only Gram-negative isolate was shown to be related to theAgrobacterium--Rhizobium branch of the α-subclass of the Proteobacteria.