Paocai is a traditional fermented food, which is loved by people because of its delicious. However, nitrite inevitably exists in Paocai, and excessive intake of nitrite will cause a certain degree of harm to the human body. Studies have shown that LAB have the ability to degrade nitrite, and AD and ED are the two main ways. In this experiment, 20 LAB strains of that can degrade nitrite were screened from Paocai water. After 30 h, the NDR of DAE was 97.69%~99.71%. L2 and L6 could degrade nitrite by high efficiency ED, which were screened by spectrophotometer. The two bacteria's NDR of DAE was 99.28% and 99.13%, and the NDR of ED were respectively 90.89% and 90.02%. The two strains were identified by molecular biology. The results showed that L2 was Lactobacillus plantarum and L6 Lactococcus lactis.
Materials and methods
SamplingFour home-made Paocai water were randomly sampled in Ya'an, sichuan province,which were kept at low temperatures and sent to the laboratory quickly.