Quantity of probiotic bacteria in home-made fermented food

Probiotici su živi mikroorganizmi, najčešće bakterije mliječne kiseline, koji imaju blagotvorno djelovanje na zdravlje domaćina. Cilj rada je identificirati probiotičke bakterije u domaćem rasolu te usporediti brojnost probiotičkih bakterija između komercijalno dostupnih probiotika, domaćeg rasola te kupovnih i domaćih mliječnih proizvoda. U radu je korišteno 9 različitih uzoraka domaćeg rasola, 4 različita kupovna probiotika, 4 kupovna mliječna proizvoda te 4 domaća. Pripremljena su decimalna razrijeđenja svih uzoraka te su nacijepljena na MRS hranjivu podlogu. Izolirane probiotičke bakterije domaćeg rasola fenotipski su karakterizirane metodom bojanja po Gramu te su identificirane tehnologijom MALDI-TOF, a utvrđeno je da su prisutne bakterijske vrste Levilactobacillus brevis i Levilactobacillus buchneri (gram-pozitivne bakterije štapićastog oblika) te Pediococcus parvulus (gram-pozitivna bakterija okruglog oblika). Ovim je radom utvrđeno da broj bakterija u uzorcima domaćeg rasola iznosi 8,17±5,03 × 107 CFU mL-1, uzorci kupovnih mliječnih proizvoda sadrže 4,11±1,62 × 107 CFU mL- , domaći mliječni proizvodi sadrže 3,20±1,91 × 107 CFU mL-1, a komercijalno dostupni probiotici sadrže 4,88±0,54 × 1010 CFU g -1. Predlaže se daljnje istraživanje s više uzoraka domaćih namirnica kako bi se detaljnije usporedile prisutne bakterijske vrste te njihove brojnosti.Probiotics are living microorganisms. They are most often lactic acid bacteria which have a beneficial effect on the host's health. This work aims to identify probiotic bacteria in homemade cabbage brine and compare the number of probiotic bacteria between commercially available probiotics, homemade brine, and store-bought and domestic dairy products. Various samples were used in the study: 9 of homemade cabbage brine, 4 of commercially available probiotics, 4 of store-bought dairy products, and 4 of homemade dairy products. Decimal dilutions of all samples were prepared and inoculated onto MRS nutrient medium. The isolated probiotic bacteria of homemade cabbage brine were phenotypically characterized by the Gram staining method. The bacteria were then identified by MALDI-TOF technology. Bacterial species observed are Levilactobacillus brevis and Levilactobacillus buchneri (grampositive rod-shaped bacteria) and Pediococcus parvulus (round-shaped gram-positive bacteria). This work determined that the number of bacteria in samples of homemade cabbage brine is 8.17±5.03×107 CFU mL-1 . Commercially available dairy products contain 4.11±1.62×107 CFU mL-1, while domestic dairy products showed 3.20±1.91 ×107 CFU mL-1. Commercially available probiotics have 4.88±0.54×1010 CFU g-1. It is suggested further research with more samples of homemade foods for a more detailed comparison of the bacterial species present and their quantity