Screening and Characterization of Nitrite Degrading <i>Lactobacillus plantarum</i> in Chinese Traditional Pickles

Abstract

A Gram-positive, non-spore, round ended, straight rod Lactic acid bacteria were screened. The strain was screened out from the traditional pickle jar in Yutang soy sauce garden of Jining. In order to degrade the nitrate content in the fermentation process of traditional pickles and improve the quality of pickles, it is necessary to screen out nitrite degrading strains from pickles, and preliminarily locate nitrite reductase, and find out the most suitable pH, tempe r ature and culture time to degrade nitrite. Lactobacillus plantarum was screened by MRS medium in advance. After 48 hours of culture in a shaking table with Bacillus subtilis , the cell components were separated by centrifugation, wall breaking and other operations. After 20 hours at 30 &deg C, the content of nitrite in each component was determined by the naphthalene ethylenediamine hydrochloride method (NIR). The culture conditions were as follows: inoculation amount 3%, 6%, 9%, 12%, 15%; salinity 2%, 4%, 6%, 8%, 10%; temperature 15&degC, 20 &deg C, 25 &deg C, 30 &deg C, 35 &deg C for 20 h. The results showed that the best degradation effect of nitrite was obtained under the conditions of 9% inoculum, salinity 5% and 30 &deg C. Under the conditions of 9% inoculum, 5% salinity and 30 &deg C for 5 h, 10 h, 20 h, 48 h, 66 h and 78 h, the results showed that the degradation amount gradually increased with the extension of time, and gradually maintained a stable state. Lactobacillus plantarum JBA-3 is a new type of lactic acid bacteria which can degrade nitrite and produce nitrite reducta se.