Lactobacillus cypricasei Lawson et al. 2001 is a later heterotypic synonym of Lactobacillus acidipiscis Tanasupawat et al. 2000

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 a-subunit (pheS) and RNA polymerase a-subunit (rpoA) were sequenced and analysed for members of the Lactobacillus salivarius species group. The type strains of Lactobacillus acidipiscis and Lactobacillus cypricasei were investigated further using a third gene that encodes the a-subunit of ATP synthase (atpA). The MLSA data revealed close relatedness between L. acidipiscis and L. cypricasei, with 99(.)8-100% pheS, rpoA and atpA gene sequence similarities. Comparison of the 16S rRNA gene sequences of the type strains of the two species confirmed the close relatedness (99-8% gene sequence similarity) between the two taxa. Similar phenotypes and high DNA-DNA binding values in the range of 84 to 97(.)5% confirmed that L. acidipiscis and L. cypricasei are synonymous species. On the basis of the present study, it is proposed that Lactobacillus cypricasei is a later heterotypic synonym of Lactobacillus acidipiscis.