Corynebacterium frankenforstense sp. nov. and Corynebacterium lactis sp. nov., isolated from raw cow milk.

Two groups of Gram-stain positive, aerobic bacterial strains were isolated from raw cow's milk, from a milking machine and from bulk tank milk. Based on their 16S rRNA gene sequences these isolates formed two distinct groups within the genus Corynebacterium. The sequence similarities of the isolates to the type strains of species of the genus Corynebacterium were below 98.4%. The presence of menaquinones MK-8(H2) and MK-9(H2), the predominant fatty acid 18:1 cis 9 and a polar lipid pattern with several phospholipids but without aminolipids was in accord with the characteristics of this genus. The results of DNA-DNA hybridization, biochemical tests and chemotaxonomic properties allowed genotypic and phenotypic differentiation of the strains from all known species of the genus Corynebacterium. Therefore, the isolates were assigned to two novel species of this genus for which the names Corynebacterium frankenforstense sp. nov. (type strain ST18(T) =DSM 45800(T) = CCUG 63371(T)), and Corynebacterium lactis sp. nov. (type strain RW2-5(T) = DSM 45799(T) = CCUG 63372(T)) are proposed, respectively.