Isolation,Identification of Leuconostoc Mesenteroides Subsp. Dextranicum and Study on Acid-Production Conditions

Total 27 strains of lactic acid bacteria were isolated from home-made pickles.After screening and re-screening,strain PC09 producing higher amount of lactic acid was obtained and determined as Leuconostoc mesenteroides subsp.dextranicum.The acid-production conditions for PC09 such as the tomato juice adding or not,fermentation temperature,rotating speed,inoculum amount were studied.The results showed that the acid-production reached 4.17% under the optimum conditions as follows:adding 1% tomato juice,fermentation temperature 33℃,rotating speed 100 r·min-1 and inoculum amount 2.0%.