Screening and identification of microorganism degrading nitrite in Chinese sauerkraut
Nitrite contamination can cause serious harm to human health, biological method is a feasible way to eliminate nitrite in food. In this study, microbial strains degrading nitrite were isolated and screened from six kinds of fermented vegetables (cabbage, broccoli, celery, turnip, carrot and cucumber) after the nitrite peak. The separated 285 strains were carried out nitrite reduction reaction test, the results showed that 21 strains could degrade more than 40 percent sodium nitrite; 86 strains could degrade more than 50 percent sodium nitrite; 114 strains could degrade more than 60 percent sodium nitrite; 64 strains could degrade more than 90 percent sodium nitrite. The 64 strains of actic acid bacteria were identified as Lactobacillus plantarum, Lactobacillus pentosus, Leuconostoc mesenteroides by biological and chemical reaction identification and 16S rRNA gene identification. These results will provide the principle and method of processing the safe products of the silage fermentation, meat fermentation and the pickled vegetable with low nitrite content.
Nitrite is a precursor substance of the strong carcinogenic nitrosamines, which can react with the intermediate secondary amine from decomposition of protein in foods to form nitrosamines, which can induce a variety of cancers such as liver cancer, stomach cancer, esophageal and pharyngeal cancer (1-3). Because superscalar nitrite contamination in food can cause serious harm, people are trying to find effective methods to control or degradation of nitrite, microbiological method is just a feasible way to eliminate nitrite in food. Screening microorganisms of degrading nitrite to reduce nitrite content in fermented vegetables, meat and feed is of great significance.
The content of nitrite in vegetables is very low (4), while the content of nitrite is higher than that of nitrate in fermentation products of vegetables (5,6). Many researchers, such as Guo Xiaohong (7), Zhou Zeyi (8), Ji Shujuan (9), Liu Qingmei (10), Liu Yulong (11), Pu Chaowen (12), Wu Zhengqi (13), Zheng Guifu (14) and Pan Hefeng (15) have studied the formation of nitrite in vegetable fermentation process, which proved that during the fermentation of kimchi, the nitrat ...