Abstract: To improve the activity of lactic acid bacterial starter cultures during their production and application, we investigated the induction and resuscitation of viable but non-culturable (VBNC) state in Lactobacillus delbrueckii subsp. bulgaricus ND02 (Lactobacillus bulgaricus ND02), which had excellent fermentation characteristics. Lactobacillus bulgaricus ND02 was cultured under different conditions to induce the VBNC state. The plate count method and fluorescence microscope were used jointly to examine the VBNC state, and then the VBNC cells were resuscitated by varying temperature and medium components. The results showed that Lactobacillus bulgaricus ND02 in MRS at 4 ℃ could enter the VBNC state after 190 days. It was also found that skim milk (10%) plus yeast powder (0.1%) was effective for resuscitation. This study would provide a reference basis to prevent Lactobacillus bulgaricus ND02 from entering the VBNC state and thus to improve its activity for future work.

Key words: Lactobacillus bulgaricus ND02, viable but nonculturable (VBNC), induction, resuscitation