Three heterofermentative lactic acid bacteria, obtained from Greek and Belgian artisanal wheat sourdoughs, were preliminarily identified as Lactobacillus brevis-like after screening using whole-cell protein fingerprinting and 16S rRNA gene sequence analysis. The three sourdough isolates showed nearly identical sequences (>99.7 % sequence similarity), and highest similarities of 98.2 and 97.6 % were obtained to the species Lactobacillus spicheri and Lactobacillus brevis, respectively. Growth characteristics, biochemical features, amplified fragment length polymorphism fingerprinting, DNA-DNA hybridizations and DNA G+C contents demonstrated that the isolates represent two novel Lactobacillus species. The names Lactobacillus acidifarinae sp. nov. and Lactobacillus zymae sp. nov. are proposed and the type strains are LMG 22200(T) (=R-19065(T)=CCM 7240(T)) and LMG 22198(T) (=R-18615(T)=CCM 7241(T)), respectively.