Screening And Functional Properties Of Probiotic Lactobacillus From Home-made Fermented Foods

As people pay more and more attention to health,probiotics products have been gradually concerned,Because lactic acid bacteria is an important source of probiotics,in recent years with lactic acid bacteria food has gradually become a priority choice.Traditional fermented foods are rich in lactic acid bacteria,but the current from the northeastern region of fermented food extraction and identification of lactic acid bacteria is less identify.Therefore,this experiment mainly from the large supermarkets in Changchun City,selected Wang Zhi He stinky tofu,fermented bean curd and Heilongjiang Province,two different rural collection of fermented food sticky face,soup noodles(ballast),homemade chili sauce samples,expected from screening of lactic acid bacteria have good probiotic functional strains.The main results are as follows:1)By observing the colony morphology,cell characteristics,microscopy,passaged stable inheritance,acid production and curd test,and finally from the identification of 11 strains of lactic acid bacteria.The results showed that: H6,H8,H9,L2,L12,L16 strains were Lactobacillus plantarum;C1 and C2 strains were Lactobacillus acidophilus;E1 and E2 were pentylococcus;L17 was Lactobacillus salivarius.2)11 strains of lactic acid bacteria were used to degrade sodium nitrite,bile salt,lactose degradation and three different methods of in vitro antioxidant test.11 strains of lactic acid bacteria were treated underdifferent conditions,respectively,to the control of Salmonella typhimurium and Staphylococcus aureus is a bacteriostatic test for pathogens.The results showed that strain L12 had the best degradation rate of sodium nitrite and the degradation rate of lactose.The degradation rate of lactose was the best,and the strain L12 was the best for three kinds of in vitro antioxidant.Free radical scavenging the best strain C2;The best strain for ferrous ion clearance is H6.3)11 strains of lactic acid bacteria had different inhibitory effects on Staphylococcus aureus and Salmonella typhimurium.The results showed that the bacteriostatic effect of the two strains treated with different conditions was different,and the supernatant of L17 strain(pH 6.5)had obvious effect on the control of Salmonella typhimurium,and that metabolic growth may produce bacteriocin or antibiotics;strains L16,H8 viable cells were typhoid Salmonella,Staphylococcus aureus has a slight bacteriostatic effect;Living bacterium group only strain L16 has significant inhibitory effect on rat typhoid Salmonella.The results showed that the bacteriostatic substance could be produced on the cell surface.After the ultrasonic disruption,only the strain L17 had obvious bacteriostatic effect on the typhoid Salmonella typhimurium,and the results of the treatment condition could be described as the strain L17 Of the bacteriostatic substance is produced inside the bacteria.4)According to the conclusion of bacteriostatic effect,the phylogenetic tree analysis of strain L17 showed that L17 was Lactobacillus,and the genetic similarity with Lactobacillus acidipiscis was 94%.