Identification of isolated lactobacillus from traditional dairy products ofMaragheh

BACKGROUND AND OBJECTIVESProbiotics are microorganisms that are beneficial for health when used in sufficientquantity.Various bacterial genera most commonly used in probiotic preparations areLactobacillus, Bifidobacterium, Escherichia, Enterococcus, Bacillus andStreptococcus.Nowdays, the research suggests that these “healthy” bacteria have beneficial effects ongastrointestinal dysfunctions, including diarrhea, as well as the immune system andconditions such as allergy, in children, adults, and in the oral cavity.MATERIALS AND METHODSTo identify the isolated bacteria from traditional Maragheh yogurt, biochemical and microbialtests including; gram staining, oxidase, catalase, hemolysis, acid and bile salt resistancemobility, nitrate reduction, SIM, sugar fermentation, antibiotic resistance, antimicrobial testswere carried out. The asparaginase and glutaminase production was evaluated by raid plateassay. The molecular identification of the isolate was down through DNA extraction, PCRamplification of ۱۶S rRNA gene, electrophoresis and construction of phylogenetic tree of theisolate via neighbor-joining method by BioEdit and MEGA softwares.RESULTS AND DISCUSSIONAccording to the results, M۲۴ isolate showed; gram-positive morphology, negative results forcatalase and oxidase tests, resistance to bile salts and acidic pH, absence of hemolysis,resistance to antibiotics, sugar fermentation and nitrate reduction. The results of molecularinvestigations revealed that the isolate had the highest genetic similarity (۹۷%) toLimosilactobacillus fermentum CECT۵۶۲(T)AJ۵۷۵۸۱۲. The nucleotide sequence of theM۲۴ isolate has been recorded in the NCBI database under accession number۵۶۸۲۰۴.Furthermore, the isolate produced asparaginase and glutaminase enzymes.CONCLUSIONDue to the probiotic potential of the isolate, its encapsulation via biopolymers is running inour lab.