Designation of ATCC 334 in Place of ATCC 393 (NCDO 161) as the Neotype Strain of Lactobacillus casei subsp. casei and Rejection of the Name Lactobacillus paracasei (Collins et al., 1989)

Strain ATCC 393 (= NCDO 161) was selected as the neotype strain of Lactobacillus casei subsp. casei by Hansen and Lessel in 1971 and was confirmed as such on the Approved Lists of Bacterial Names in 1980. However, two independent DNA-DNA homology studies have shown that strains belonging to the subspecies of L. casei are not genetically closely related to strain ATCC 393T (T = type strain). In 1989 Collins et al. found high levels of DNA homology between strains belonging to the subspecies of L. casei and L. casei NCDO 151 and reclassified L. casei subsp. casei (the majority of the strains), L. casei subsp. alactosus, L. casei subsp. pseudoplantarum, and L. casei subsp. tolerans as Lactobacillus paracasei. However, results obtained from DNA-DNA hybridization experiments and a computerized numerical analysis of total soluble cell proteins indicated that authentic strains belonging to the subspecies of L. casei are genotypically closely related to L. casei subsp. casei ATCC 334. According to Rules 18g and 18i of the International Code of Nomenclature of Bacteria, replacement of a neotype strain can be requested if “an original strain that should constitute the type of a species is discovered subsequent to the final proposal or establishment of a neotype for that species” or if the neotype has become “unsuitable due to changes in its characters or for other reasons.” We request that the Judicial Commission designate strain ATCC 334 in place of ATCC 393 as the neotype strain of L. casei subsp. casei. Furthermore, we request that the species name L. paracasei be rejected.