Aims To characterize a psychrotrophic bacterium, designated TC1, previously isolated from a cattle hide in Ireland, and to investigate the ability of this strain to cause blown pack' spoilage (BPS) of vacuum-packaged beef primals. Methods and Results TC1 was characterized using a combination of phenotypic, chemotaxonomic and genotypic analyses and was assessed for its ability to spoil vacuum-packaged beef at refrigerated temperatures. TC1 was Gram-positive and formed elliptical subterminal endospores. The strain was able to grow between 0 and 33 degrees C, with optimal growth between 23 and 24 degrees C. TC1 could be differentiated from its phylogenetically closest neighbour (Clostridium lituseburense DSM 797T) by 16S rRNA gene sequencing, pulsed-field gel electrophoresis and cellular fatty acid composition. TC1 spoiled (BPS) beef within 42days when inoculated in cold-stored (1 degrees C) vacuum-packed beef. Conclusions The phenotypic, chemotaxonomic and genotypic characterization indicated that TC1 may represent a potentially novel, cold-tolerant, gas-producing bacterium of considerable economic significance to the beef industry. Significance and Impact of the Study This study reports and characterizes an emerging BPS bacterium, which should be considered in future activities designed to minimize the psychrophilic and psychrotrophic spoilage of vacuum-packaged beef.