Abstract:β-N-Acetylhexosaminidase -β-Hexcase-, produced by a wide variety of bacteria, plants and animals, behaves like typical exo-enzymes, catalyzing the cleavage of terminal non-reducing N-acetyl-β-hexosamine residues with important physiological roles in cell wall recycling. The β-hexcase sequence of relevant strains genetically close to Lactobacillus delbrueckii subsp. bulgaricus LJJ was selected, and degenerate primers were designed using online ICODEHOP and CODEHOP software. A pair of degenerate primers named hex1-f and hex1-r was chosen for PCR with the LJJ genome DNA as a template. A 614 bp PCR product was obtained, and was transformed into E. coli DH5α using pGEM-T vector and sequenced after extraction of plasmids. Similarity alignment showed that the sequence of the cloned DNA was similar to those of known β-hexcase gene from other bacterial strains. Therefore, the cloned sequence was confirmed to be the putative β-hexcase gene fragment from LJJ strain. The results obtained in this study would provide basis for studying roles of β-Hexcase in cell wall lysis of Lactobacillus delbrueckii subsp. bulgaricus strains.