Study On Screening Of Excellent Lactic Acid Bacteria For Silage And Apple Pomace Fermentation Experients

The method of observing dissolved calcium circle was used to separate lactic acidbacteria, according to catalase, fermentation of glucose to produce acid and gas characteristics,the growth curve of strain and acid production rate, excellent acid bacteria strains wasscreened. In addition, the growth rule and the acidity production character of the good strainswas studied further. Through silaging with single lactic acid bacteria and different lactic acidbacteria combination, analysed the living count of lactic acid bacteria, organic acid contentand the change of different nutrient indexes, the optimal strain combination was screened. Itwould provide theoretical reference for apple pomace production. The main results ofresearch are as follows:(1) Four strains of lactic acid bacteria which grow fast, produce more acid and tolerateacid were screened, named R7, Rg, R3, Re respectively. The good strains were identifiedthrough morphological observation, physiological and biochemical tests, and16S rDNAsequence analysis, R7is Lactobacillus plantarum, Rg is Lactobacillus fermentum, R3isLactobacillus pentosus, Re is Lactobacillus rhamnosus.(2) The biological character study showed: All the strains can grow between15to50℃.Strain R7grows fastest and has the strongest acid produce capacity, lactic acid content is thehighest in fermentation liquid of R7, accounting for95.40%of the total acid content, it cangrow well at the condition of pH3.0, also can tolerate mass concentration0.08g/mL NaCl.The growth and acid production of Re, R3take second place, they also has strong ability ofacid and alkali resistance. Rg grows well in50℃, which shows strong high temperaturetolerance.(3) The optimal strain combination screening results: This test used apple pomace asmaterials for the single silage which added lactic acid bacteria and fermented via the small potat laboratory, the sensory quality of silage was excellent; Adding lactic acid bacteriasignificantly improved the content of lactic acid, reduce the formation of butyric acid.The pHdecreased rapidly and nutrient loss reduced; The group R7+R3is the optimum straincombination which was suitable for pomace silage, namely adding Plant lactobacillus andPentose lactobacillus in the silage: The number of lactic acid bacteria in group R7+R3 reached the highest9.05×108CFU/g FM on the following day, and at the end of silage, theeffective number of bacterium still maintained at1×107CFU/g FM; Lactic acid productionand LA/AA of group R7+R3was significantly higher than other groups, the total acid contentis5.59g/kg after45days; NH3-N/TN (%) of group R7+R3was the lowest,13.02；DM and CPcontent of group R7+R3was obviously higher than other groups,294.3g/kg and9.28%respectively; WSC preserving rate of group R7+R3was the biggest,91.37%.(4) Effect of compound microbial additives on apple pomace showed: Addingcompound microbial additives for pomace silage obtained good effect, lactic acid bacteria andyeast could survive together vigorous, the pH value decreased rapidly, the ratio of ammonianitrogen to total nitrogen decreased obviously, and the quantity of bacillus maintained105CFU/g FM, it could adjust intestinal flora in the process of animal feeding.