Isolation of Lactobacillus from fruit juices

BSc student: Dzelila Jusic

Mentor: Assist. Prof. Dr. Altijana Hromic-Jahjefendic

Year: 2019

Probiotics are playing excruciatingly important role in human and animal health. They also serve as very good protectors from destructive antibiotics as they are highly resistant to them.  Moreover, strong scientific evidences imply that probiotics can fight conditions such as diarrhea, vaginal infections and skin disorders. Among the microorganism having probiotic properties,  Lactobacillus  genus is the broadly used one, besides Bifidobacterium. Naturally ocurring in human gut, especially in GI tract, having more then 221 strains discovered to date, Lactobacillus genus is being isolated from conventional (diary) products, and now even unconventional sources like non- diary non-fermented foods, non- diary fermented foods and beverages such as fruits and fruit juices. Later on are being used  for their probiotic properties and health benefit for humans.In this study the goal was to isolate Lactobacillus from several different fruit juices, by using Lactobac HybriScan D, which is rapid molecular test for isolation of Lactic Acid Bacteria from non-alcoholic drinks. This molecular test proved sucessful in isolation of Lactobacillus based on morphological and biochemical tests done after the isolation of bacteria. Gram staining, catalase, motility and starch degradation tests were performed after subculturing of isolates. This graduation project ougth to prove the existence and prevalence of Lactobacillus in raw  fruit juices of apple, banana, mango, orange, pineapple and tomato. All the analysis done confirmed quality and quantity of these probiotics in freshly squeezed juices over those in canned and commercially prepared ones.