Isolation And Identification Of Lactic Acid Bacteria In Fermented Soup Of Miao And Its Fermentation Kinetics

Sour soup is kind of traditional fermentation food, which is divided into red sour soup and white sour soup in Miao areas. The pepper and tomato are added in the white sour soup, through a fermentation period, then obtain the red sour soup. White sour soup is kind of natural food. White sour soup is made by the fermentation of lactic acid bacteria, acetic acid bacteria in the rice soup, which has the health-care effect of clearing summer-heat, regulating the hunman gut microflora balance, improving the health of the hunman body and preventing gastrointestinal diseases.However, for a long time, the production method about the traditional white sour soup is using natural fermentation,belonging to family mill production.That has the following disadvantages,the small size, fermentation substrate concentration low, longer fermentation period, the unstable product quality, rebelillious quality and health standards.The basic research of the Hmong sour is very weak, which severely restricts its industrialized production.In this paper, the Hmong farmers sour soup was used as raw materials, using physiological and biochemical identification and molecular identification method, the separate identification of lactic acid bacteria, to study their biological characteristics and fermentation kinetics model, and aimed at understanding the main function of the natural fermentation of lactic acid bacteria species and activity in white sour, and to lay the foundation for futher industrialization production of white sour soup, and to provide theoretical support for artificial inoculation bacterial strain in the fermentation sour soup. Experiment are as follows:1、The psysical and chemical indicators,and Microbes living bacterium number were determined in the natural fermentation white sour soup:fermentation mature white sour soup was at pH3.2, total acid1.0%, soluble solids content of5%, total sugar2.6%, protein0.1%, the number of total bacteria2.6×106cfu/mL, the number of viable cells of lactic acid bacteria of2.0×106cfu/mL. It was found that in the modified MC medium, optimal lactic acid bacteria count, the maximum number of living bacterium, the largest soluble calcium cricle. 2、For strians of lactic acid bacteria were isolated from the natural fermentation of mature white sour soup,using traditional morpological method,physiological analysis method and16s rDNA sequence analysis method, to proceed a systematic bacteriology identification.The identification resultes show that the dominant lactobacillus is gram-postive bacterium, getting lactic acid-producing strain of Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus lactis, Streptococcus thermophilus.3、The kinetics of the lactic acid bacteria fermentation was studyed,and the kinetics model of the cell growth quantity,lactic acid production and consumption of substrate were established.Logistic and Luedeking-Piret equation for lactic acid bacteria fermentation process is described, application Origin6.0mathematical software on cell growth kinetics, Lactate production kinetics and substrate consumption dynamics of nonlinear curve fitting, come to the kinetic model parameters good fitting results, description of the selected model can better reflect the dynamic mechanism of lactic acid fermentation process, which can be used further design of large fermentation process.4、Single strain and strain mixed fermentation quality of sour soup comparative test results show that multiple strain fermentation acid production and the flavor is better than a single bacterium.