Sabri M. Naser,  Marc Vancanney, Bart Hoste, Cindy Snauwaert, and Jean Swings

The applicability of a multilocus sequence analysis (MLSA)-based identification system for Lactobacilli was evaluated. Two housekeeping genes that code for the phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA) were sequenced and analyzed for members of the Lactobacillus salivarius species group. The type strains of L. acidipiscis and L. cypricasei were further investigated using a third gene that codes for the alpha subunit of ATP synthase (atpA). The MLSA data revealed high relatedness between Lactobacillus acidipiscis and Lactobacillus cypricasei with 99.8 - 100 % pheS, rpoA and atpA gene sequence similarities. Comparison of the 16S rRNA gene sequences of the two taxa confirmed high relatedness between the type strains of the two species (99.8 % 16S rRNA gene sequence similarity). Similar phenotypes and high DNA–DNA binding values in a range of 84% to 97.5 %, confirmed that L.  acidipiscis and L. cypricasei are synonymous species. Data from the present study led to the proposal that L. cypricasei is a later synonym of L.  acidipiscis.