The aim of this study was to develop PCR primer sets for the rapid classification of lactic acid bacteria (LAB). Published gene sequences for LAB carbohydrate metabolic enzymes were collected from the NCBI GenBank, and 45 primer sets were designed using the gene sequences. Twelve species of LAB were used as reference strains: Lactobacillus brevis, Lactobacillus farciminis, Lactobacillus fermentum, Lactobacillus hilgardii, Lactobacillus plantarum, Weissella cibaria, Weissella confusa, Weissella kimchii, Leuconostoc citreum, Leuconostoc lactis, Pediococcus acidilactici, and Pediococcus pentosaceus. PCR amplification and gel electrophoresis were performed to verify the specificities of the designed primers. The results showed that the primer set No. 1 of 5'-aacaacaaaatcaccgcaca-3' & 5'- gtcgtcaatgttgtcgatgc-3' for phosphofructokinase amplified PCR products from 5 species of heterofermenter with different molecular weight depending on the genus. Primer set No. 8 of 5'-gcgtcgccgtctcg-3' & 5'- gcctgcggcttttcg-3' produced specific PCR products from three heterofermentative lactobacilli such as L. brevis, L. fermentum, and L. hilgardii. Primer set No. 18 of 5'-gtgacggtgctgtaggttca- 3' & 5'-gcagtcgcttacgccatatt-3' was specifically reacted to homofermentative species including L. farciminis, P. acidilactici, and P. pentosaceus. Hence, the primer sets which were developed in this study could be used as a tool for the classification and differentiation of homo- and hetero fermentative species in lactic acid fermented foods, like as kimchi.

Abstract
 Introduction
 Materials and Methods
  Reference strains
  DNA extraction from lactic acid bacteria
  Development of identification primer
  PCR amplification
  Electrophoresis analysis of PCR product
 Results and Discussion
  Primer design based on metabolic enzyme gene sequences
  PCR analysis of lactic acid bacteria with designedprimers
 References

• Myung-Ki Lee(Fermentation Food Research Center, Korea Food Research Institute) Corresponding author
• Hyo Jin Kim(Fermentation Food Research Center, Korea Food Research Institute)
• Kyung Mo Song(Fermentation Food Research Center, Korea Food Research Institute)
• Sung Hoon Yi(Fermentation Food Research Center, Korea Food Research Institute)
• Young-Kyoung Rhee(Fermentation Food Research Center, Korea Food Research Institute)
• Sung-Won Moon(Department of Hotel & Foodservice Culinary Arts, Youngdong University)
• Yu-Ri Kim(Fermentation Food Research Center, Korea Food Research Institute)