Lactic acid microorganisms (LAB) are broadly employedin hard food production and are measured as generally recognized as safe (GRAS)organismsLAB produces little organic compounds that providethe aroma and flavor to the fermented product. In the food manufacturing, LABis extensively used as starter cultures and has been indexed as part of humanmicrobiota .Lactobacillus spp.
has become more and more originate use as Probioticsin foods. Probiotics are live bacteria andyeasts that are superior for your health, particularly your digestive system. LABis used commonly in milk product which is very important in human developmentand health. Fermented foods are popularly accepted for their flavor, betterkeeping quality, and the fact that fermentation creates variety among foods. Thestudy was aimed at isolation and molecular characterization of lactic acidbacteria (LAB) from soursop, cowmilk, goatmilk yoghurts and cheese.Yoghurtis among the most common dairy products consumed around the world. Differentvarieties of wild fruits could be of health benefit, one such is soursop fruit(Annona muricata). They are fruits that are good sources of vitamins andminerals.
Goat milk is naturally predisposed for preparing a yoghurt drink thatis light and easily digestible. Fermented drinks made of goat milk differ fromthe drinks made of cow milk, among other things, by a lower content of volatilearoma compounds (and especially of acetaldehyde and carbon dioxide. Cheese iswhite soft non-ripened milk made by the addition of a plant extract (Calotropisprocera) to the non-pasteurized whole milk from cattle.
Twenty-fourbacterial strains were isolated, according to biochemical identification andonly 16 were characterize as: Lactobacillus plantarium, Lactobacillusfermentus, Bacillus substilis, Bacillus subsitils, Lactobacillus rhaminosus,Lactobacillus fermentum, Lactobacillus paracase, Lactobacillus licheniformis,Lactobacillus planetarium, Lactobacillus licheniformis, Bacillus substilis,Lactobacillus paracasei, Lactobacillus fermentus, Lactobacillus fermentus,Lactobacillus licheniformis, Lactobacillus rhaminouus, Lactobacilluslicheniformis. Theisolates were characterizing on the basis of their morphological, biochemical,physiological and 16S rRNA gene sequences. All of the isolates were wellidentified with the help of molecular techniques. A total number of 24 isolates were picked from MRSagar plates and were found to belong to the genus Lactobacillus, according totheir physiological and biochemical tests. The isolated bacteria were stored inMRS broth culture in temperature -800C for further analysis. The isolates weregram positive when view under light microscope, hence they were gram positivebacteria. They appeared as a chain of 3-4 cells (rounded rods, cocci) in shape,and catalase negative bacteria. All the isolates were subjected to test for gasproduction from glucose and the test tubes observed for 5 days and there was nogas accumulation in Durham tubes.
For identification of bacilli isolates, thegrowth at 15°C and 45°C were used. However, Lactobacillus delbrueckii sspbulgaricus cannot grow at 15°C but can grow at 45°C.Thisstudy showed that the biochemical, physiological and morphological tests inlactobacillus spp. were dominant in dairy products used while Bacillussubstilis was present in soursop yoghurt (non-dairy).
It can be stated that LABisolated can be potentially Probiotics bacteria with promoting host-specifichealth.