Leuconostoc spp. are generally utilized as kimchi starters, because these strains are expected to have beneficial effects on kimchi fermentation, including improvement of sensory characteristics. Here, we developed a detection method for verifying the presence of the kimchi starter Leuconostoc mesenteroides WiKim33, which is used for control of kimchi fermentation. A primer set for multiplex polymerase chain reaction was designed based on the nucleotide sequence of the plasmids in strain WiKim33, and their specificity was validated against 45 different strains of Leuconostoc spp. and 30 other strains. Furthermore, the starter strain consistently tested positive, regardless of the presence of other bacterial species in starter kimchi during the fermentation period. Our findings showed that application of a strain-specific primer set for strain WiKim33 presented a rapid, sensitive, and specific method for detection of this kimchi starter strain during natural kimchi fermentation.

Abstract
 I. Introduction
 II. Material and Methods
  1. Leu. mesenteroides WiKim33-specific primer design
  2. DNA extraction and amplification by multiplex PCR
  3. Examination of sensitivity and specificity
  4. Preparation of kimchi
  5. pH and acidity
  6. Total viable bacteria, LAB counts, and WiKim33population ratio in kimchi samples
 III. Results and Discussion
  1. Design of the multiplex primer set for Leu.mesenteroides WiKim33 detection
  2. Detection limit of the designed primer set
  3. Application of WiKim33-specific PCR for sensingstarter-inoculated kimchi
 IV. Summary and Conclusion
 References

• Moeun Lee(Advanced Process Technology and Fermentation Research Group, World Institute of Kimchi)
• Jung Hee Song(Advanced Process Technology and Fermentation Research Group, World Institute of Kimchi)
• Ji Min Park(Advanced Process Technology and Fermentation Research Group, World Institute of Kimchi)
• Ji Yoon Chang(Advanced Process Technology and Fermentation Research Group, World Institute of Kimchi) Corresponding author