Lactobacillus algidus sp. nov., a psychrophilic lactic acid bacterium isolated from vacuum-packaged refrigerated beef

Lactobacillus algidus sp. nov. is described on the basis of 40 strains isolated as one of the predominant bacteria from five specimens of vacuum-packaged beef collected from different meat shops and stored at 2 degrees C for 3 weeks. These strains were quite uniform in the overall characteristics examined. They are facultatively anaerobic, psychrophilic, Gram-positive, non-spore-forming, non-motile, lactic acid-homofermentative rods. The cells occurred singly and in pairs on agar media and in rather long chains in broth media. They differed in several cultural and biochemical characteristics from the authentic meso-diaminopimelic acid-positive or psychrophilic lactic acid bacteria in the genera Lactobacillus, Carnobacterium and Brochothrix. The SDS-PAGE whole-cell protein pattern was clearly distinctive. DNA-DNA hybridization and phylogenetic analysis of 16S rDNA also failed to associate these strains closely with any of the validly described organisms used. The phylogenetic analysis showed that these strains are rather remotely but most closely related to Lactobacillus mali (93% sequence similarity), which belongs to the Lactobacillus casei/Pediococcus group. Therefore, these strains should be included in the genus Lactobacillus and considered to represent a new species, Lactobacillus algidus sp. nov. The type strain is M6A9T (= JCM 10491T).