Although four strains of bacteria isolated from sunki, a traditional Japanese, non-salted pickle, were initially identified as Lactobacillus delbrueckii, the molecular and phenotypic characteristics of the strains did not match those of any of the four recognized subspecies of L. delbrueckii. Together, the results of phenotypic characterization, DNA-DNA hybridizations (in which the relatedness values between the novel strains and type strains of the recognized subspecies of L. delbrueckii were all >88.7%) and 16S rRNA gene sequence, amplified fragment length polymorphism (AFLP) and whole-cell MALDI-TOF/MS spectral pattern analyses indicated that the four novel strains represented a single, novel subspecies, for which the name Lactobacillus delbrueckii subsp. sunkii subsp. nov. is proposed. The type strain is YIT 11221(T) (=JCM 17838(T) =DSM 24966(T)).