The Effect Of Single And Mixed Lactic Acid Bacteria Fermented Fruit And Vegetable Milk Beverage On The Laxative Effect Of Mice

The inhibitory effect of probiotics on pathogenic microorganisms and adhesion colonization ability is the basis of probiotics to improve the intestinal function.In this study,six strains of lactic acid bacteria obtained in the laboratory were used as the research object.The antimicrobial activity and the adhesion ability of single and mixed lactic acid bacteria and were analyzed.The laxative effect of single and mixed lactic acid bacteria of fruit and vegetable milk beverages was studied.The main findings are as follows:(1)Effects of single and mixed lactic acid bacteria on antibacterial capacity.Lactobacillus rhamnosus grx19,Lactobacillus acidophilus ss,Lactobacillus plantarum s7,Lactobacillus casei g9,Bifidobacterium animalis BLC and Streptococcus thermophiles 90-57,were produced by laboratory.To study the antibacterial activity of single and mixed lactic acid bacteria against three Gram-positive pathogens and three Gram-negative pathogens.The ability to produce acid,growth rate and the number of living bacterium for mixed lactic acid bacteria is high level between the single strain.Mixed fermentation has the inhibition on three Gram-positive bacteria and three Gram-negative bacteria,which has wider antimicrobial spectrum,and it increases obviously for bacteriostatic range to 6 different strains of lactic acid bacteria fermentation group.Principal component analysis showes that the antibacterial effect of mixed fermentation of lactic acid bacteria was higher than any single strain.On the analysis of lactic acid bacteria antibacterial active ingredients,in addition to lactic acid,lactic acid bacteria and mixed fermentation of fermented product exists other antimicrobial substances.In the mixed fermentation process,the strain of collaborative metabolism is sensitive to heat and protein enzyme antibacterial substances,and the main antibacterial substances,under low pH synergy,can play a good antibacterial effect,which enhances the mixed fermentation strains broad spectrum of antibacterial and bacteriostatic effect.(2)Effects of single and mixed Lactic acid bacteria on adhesion of intestinal epithelial cells in mice.To carry out research on adhesion of intestinal epithelial cells in mice of three Gram-positive bacteria and three Gram-negative bacteria inhibited by single strain of bacteria or mixed in proportion 1:1:1:1:1:1.The surface hydrophobicity,self-polymerization ability and adhesion cell capacity of lactic acid bacteria were significantly different(P<0.05),the surface hydrophobicity,self-polymerization capacity and adhesion of L.casei g9,L.plantarum s7 and the mixed strains were optimum.The inhibition effect of lactic acid bacteria to adhesion of three Gram-positive bacteria and three Gram-negative bacteria to intestinal epithelial cells in mice was followed by excludable inhibition,competitive inhibition and alternative inhibition.Single strain of bacteria was only valid to a part of bacteria to inhibit adhesion.The adhesion inhibition effects of the fermentation of mixed strains to three strains of Gram-positive bacteria and three Gram-negative bacteria on cell adhesion were better and the adhesion inhibition rates were 71.09%,66.04%,61.37%,73.97%,66.97%,68.63%.After the treatment of pepsin,trypsin and lithium chloride,there was a significant difference(P<0.05)in the adhesion to cells between the fermentation of mixed strains and single strain of bacteria.The relative adhesion rates of the mixed strains were 48.13%,43.47%and 29.18%after the treatment with pepsin,trypsin and lithium chloride,which were lower than that of the single strains of bacteria.By means of the re-binding experiments of surface protein and cell wall reversibly,the maximum increase in adhesion rate was 45.8%after the fermentation of mixed strains were incubated with surface proteins.(3)Preparation of mixed lactic acid bacteria fermented fruit and vegetable milk beverage.By means of the research of acidity,viable count and antibacterial function which influenced by the fermentation temperature and time of fruit and vegetable fermented milk beverage by the mixed strains of bacteria,and reaching the conclusion that the highest rate of acid production and the highest viable count were the highest in the fermentation of 38? for 24h,and the antibacterial activity was the strongest.The suitable addition of banana,sweet potato and oligofructose was 15%,10%,3%after researching the effects of them on the quality of mixed lactic acid bacteria fermented fruit and vegetable milk beverage by the single factor experiment.The optimized recipes of mixed lactic acid bacteria fermented fruit and vegetable milk beverage was as follows:the whey powder and skim milk were fermented substrates(containing 5%whey powder and 3%skim milk powder),the amount of banana was 15.67g/100g,the amount of sweet potato was 10.44g/100g and the amount of oligofructose was 2.23g/100g by response surface methodology.(4)Study on laxative effect of mixed lactic acid bacteria fermented fruit and vegetable milk beverage.Through the analysis of the first defecation time,the number of black fecal particles in six hours,the quality of defecation and the propulsion rate of ink in small intestine,it was found that the effect of lactic acid bacteria fermented beverage group was better than positive control group,in defecation function of constipated mice,the results showed that the multi-strain mixed fruit and vegetable fermented milk beverage group had the best effect,followed by the multi-strain mixed fermented milk beverage group and single-strain fermented milk beverage group.The results showed that the growth and reproduction of Enterococcus and Escherichia coli were inhibited in different concentrations,and the lactic acid bacteria mixed fermentation and fruit and vegetable milk beverage group and lactic acid bacteria mixed fermented milk beverage group were significantly lower than the model control group(P<0.05),and the bacteriostatic effect was significant.Lactic acid bacteria mixed fermented milk beverage groups and positive control group were improved the content of NO and AchE in serum,lactic acid bacteria mixed with fruit and vegetable milk were not significantly different from those in blank control group(P>0.05),which could make the constipation mice return to normal level,which indicated that lactic acid bacteria were the best.(5)Study on the correlation between bacteriostasis ability and adhesion capability of single and mixed lactic acid bacteria in vitro and defecation index of mice in vivo.The results showed that the bacteriostasis of lactic acid bacteria and the ability of inhibiting the adhesion of pathogens were significantly correlated with the defecation ability,small bowel movement ability,the number of enterococcus and intestinal neurotransmitter in constipation mice.Mixed lactic acid bacteria fermentation of fruit and vegetable milk beverage group,g9 single strain of fruit and vegetable milk beverage group can alleviate the symptoms of constipation in mice,mixed lactic acid bacteria fermented fruit and vegetable milk beverage group in promoting the defecation of mice,inhibition of intestinal pathogens,regulating intestinal motility neurotransmitter had the best effect.