Study On The Characteristic Analysis And Simulated Intestinal Survived Colonization Of Lactic Acid Bacteria From Pickles

Lactic acid bacteria not only endow excellent flavor and nutrition for food, but also couldregulate gastrointestinal, improve immunity and other effects for human. But only the excellentones have stronger tolerance to the environment and play a better effect. As a result, exploringthe characterization of lactic acid bacteria and researching further development to use as viablepreparation are of great significance.The strains were isolated from pickles based on colony morphology. According to theanalysis of Gram stain, individual morphology, catalase test, the measure of pH for thesupernatant, anaerobic and aerobic cross-experiment,24strains of lactic acid bacteria werescreened initially. The colonies were round, smooth and moist surface, neat edges and milkywhite, white or yellow. The individual forms were rod or short rod, no spores.The analysis of24lactic acid bacteria from safety, considering hemolytic and production ofhistamine, were tested. Hemolytic shows that all bacteria were hemolysis negative, as Vibrioalginolyticus and Vibrio parahaemolyticus were α and β-hemolytic hemolytic positive controls.From the production of histamine, all bacteria showed histamine negative features except K6H1.23strains that hemolysis and histamine appeared negative were processed antibacterialactivity tests.16pathogenic strains were selected as indicator bacteria, which were almost vibriostrains and could lead to illness to aquatic products and human beings. The result concluded thatlactic acid bacteria supernatants could inhibit the growth of pathogenic bacteria, especially Vibriostrains. The better strains were K4H2、K5H2、K1H2、K3H1�'�K4H3, and K4H2has a strongerantibacterial effect for12pathogens. Using the viable bacteria to validate, the appearance wasconsistent with supernatants. This experiment proved that the lactic acid bacteria have greatpotential in terms of human diseases due to Vibrio cholerae, Vibrio alginolyticus and otherpathogenic bacteria.Five strong antibacterial activity strains were selected to a preliminary study in colonizationeffect of simulated intestinal. The acid test of simulated gastric juice and bile resistant experimentshowed that five lactic acid bacteria have different degrees of tolerance. The stronger strains wereK4H3, K1H2and K4H2, which have showed great potential in the gut colonization. Antibioticresistance test showed that the order of antibiotic resistance for the five lactic acid bacteria was asfollows: K4H2>K4H3>K3H1>K1H2>K5H2, and the strains have the strongest resistance against vancomycin, and the most sensitive for cephalothin. The test of cell surface hydrophobicityproofed K4H2, K3H1and K4H3have better adsorption of organic reagents and have strongerability to colonize the intestinal tract. Then the β-galactosidase test explained that K4H3, K3H1and K4H2would base on stronger activity to play a greater role in the intestine after colonization.Comprehensive analysis of these, K4H2and K4H3were selected as two bacteria strains ofsuperior traits.After alignment of homologous sequences, the16S rRNA identified that the two superiortraits strains were belong to Lactobacillus. And the two bacteria initially were identified as thesame species of Lactobacillus plantarum.