Food Biotechnology
Elahe Isvand Heydari; Hossein Jooyandeh; Mohammad Hojjati; Behrooz Alizadeh Behbahani; Mohammad Noshad
Abstract
Introduction: Probiotics are viable microbial food supplements that, when well-arranged in adequate amounts, confer a health advantage on the host. Probiotics have different positive health impacts such as equilibration of intestinal microbiota, prevention of cancer and diarrhea, reduction of cholesterol ...
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Introduction: Probiotics are viable microbial food supplements that, when well-arranged in adequate amounts, confer a health advantage on the host. Probiotics have different positive health impacts such as equilibration of intestinal microbiota, prevention of cancer and diarrhea, reduction of cholesterol and blood pressure, adaptation to lactose intolerance, improvement of immune system, decrease of allergic symptoms, inhibition of pathogenic microorganisms etc. Lactic acid bacteria (LAB), are the most common bacteria introduced as probiotics. Materials and methods: In this research, a strain of Lactobacillus planetarium LZ95 was utilized and its probiotic potential was evaluated. This strain had been isolated from a traditional Iranian fermented food known as Ash-Kardeh and had been identified using culture-dependent methods and molecular techniques. Lactobacillus planetarium, is one of the known LAB bacteria. The aim of this study was to evaluate the probiotic potential of Lactobacillus plantarum LZ95 in relation to its resistance to acid (pH 2.5, 3.5 and 5.5), its ability to grow in different bile salt concentrations (0.2, 0.5, 0.8, 1.2 and 3%), its resistance against chloramphenicol, tetracycline, penicillin and gentamycin antibiotics, and its antimicrobial activity against Listeria innocua, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli by using “Lawn on the spot” method. Results and discussion: Results shown that the viability of Lactobacillus plantarum ranged from 0 to 97.69 percent. The highest and the lowest bacteria viability were determined at pH=5 and 2, respectively. The results revealed that Lactobacillus plantarum was able to grow at all tested bile salt concentrations (0.2, 0.5, 0.8, 1.2 and 3%), and the lowest and the highest viability was found at 0.2 and 3 percent of bile salt levels, respectively. Lactobacillus plantarum was susceptible to all tested antibiotics. Results also shown that chloramphenicol with an inhibition zone diameter of 30.10 mm had the highest anticipation effect on the strain. Antimicrobial activity of Lactobacillus plantarum against Staphylococcus aureus (gram positive) and Escherichia coli (gram negative) with inhibition zone diameters of 11.30 and 7 mm was the highest and the lowest, respectively. The inhibition zone diameter around the strain of Lactobacillus plantarum revealed its ability to inhibit the growth of selected pathogenic bacteria. Based on results, the inhibition zone diameter against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Listeria innocua were 11.30, 7.00, 10.70, and 8.90 mm, respectively. In general, the isolated strain of Lactobacillus planetarium LZ95 had an acceptable probiotic potential such as resistance to bile salt and acidic conditions, susceptibility to some commonly antibiotics, and appropriate antimicrobial activity against food pathogenic bacteria. Therefore, this strain can be used in food industry to produce functional food products.
