Clostridium frigidicarnis sp nov., a psychrotolerant bacterium associated with 'blown pack' spoilage of vacuum-packed meats

Two strains of a psychrotolerant Clostridium, isolated from vacuum-packed, temperature-abused beef, were characterized using a multiphasic approach. T he strains were Gram-positive motile rods producing elliptical subterminal spores during early stationary growth phase. The strains were psychrotolera nt. At ph 7.0, they grew between 3.8 and 40.5 degrees C; their optimum grow th temperature was 30.0-38.5 degrees C. At 30 degrees C, the pH range for g rowth was between 4.7 and 9.5; the optimum ph for growth was 6.4-7.2. The o rganisms were proteolytic and saccharolytic, lecithinase-positive and hydro lysed gelatin. The fermentation products formed in peptone/yeast extract/gl ucose/starch broth were acetate, ethanol, butyrate, isovalerate, butanol, i sobutyrate, oxalacetate, lactate, hydrogen and carbon dioxide. The DNA G+C compositions of the two meat strains were 27.3 and 28.4 mol%. Phylogenetic analyses indicated that the strains belong to Cluster I of the genus Clostr idium (sensu Collins et al., 1994). The new strains differed from phylogene tically related clostridia in terms of cellular fatty acid composition, sol uble protein profiles and phenotypic properties. On the basis of phenotypic and genotypic characterization data, the strains were assigned to a new sp ecies for which the name Clostridium frigidicarnis is proposed; strain SPL7 7A(T) (= DSM 12271(T)) is the type strain.