Screening and characterization of an excellent Lactobacillus isolated from pickle

To obtain excellent and pure breed strain suitable for producing fermented vegetable products,strains were isolated,screened from pickle using plate screening as well as fermentation screening method. And then,optimizing species were identified using morphological,physiological and biochemical properties and 16 S rDNA analysis technology. Finally,further study on fermentation characteristics of the target strain carried out a series of fermentation test. A strain named LP-09,with maximum lactic acid-producing,was isolated from pickle and identified as Lactobacillus plantarum. Results of fermentation tests showed that the optimal temperature and initial p H suitable for strain LP-09 were 37 ℃ and 6.0,respectively. Meanwhile,the strain owned better salt tolerance because it could grow normally in culture media with 40 g/L Na Cl,or could keep fermenting and producing lactic acid even at 100 g/L Na Cl concentration continuously and slowly. At the same time,strain LP-09 possessed quite strong ability to degrade nitrite and degradation rate of 200 mg/L nitrite could reach more than 99.3%.