first isolation and molecular detection of autochthonous potential probiotic lactobacilli isolates from iranian traditional poosti cheese and their antioxidative activity

Introduction: poosti cheese is an artisanal cheese produced mainly from ewe’s milk in southwest iran. the objective of this study was to identify lactobacilli isolated from poosti cheese and to investigate their potential probiotic and antioxidative properties. materials and methods 101 gram-positive bacilli with catalase-negative reaction were isolated from poosti cheese. twenty isolates were selected based on their highest acid and bile salt tolerability. using genus-specific primers, 10 isolates out of these were identified as lactobacillus, and they were subsequently identified at species level using 16s rrna gene sequencing. in vitro tests were used to assess their probiotic properties or antioxidative activities. results: six species were lactobacillus plantarum, and the rest was lactobacillus paracasei, lactobacillus acidophilus, lactobacillus brevis, and lactobacillus buchneri. the acid and bile tolerances were quantitatively close to the reference probiotic strain. l. plantarum s32e showed the highest survival under simulated gastric or intestinal conditions. cholesterol reduction ability of l. plantarum s12e and l. acidophilus s37a was significantly higher than that of the reference strain. l. acidophilus s37a and l. plantarum s12e were more susceptible against common antibiotics. it was found that the highest antimicrobial activity was detected in the case of listeria monocytogenes, and the extent of the activity was species and straindependent. the best result of dpph radical scavenging activity and hydroxyl radical scavenging activity was achieved by intact cells of l. paracasei s5d and by intracellular cellfree extracts of l. plantarum s8d, respectively. the results indicated that the superoxide dismutase activity of lactobacillus could not be regarded as an appropriate predictor of antioxidative traits. the highest glutathione content belonged to l. acidophilus s37a and l. parcasei s5d. discussion and conclusion: overall, some of lactobacillus strains of poosti cheese could be considered as potential probiotic candidates; it should, however, be confirmed by further in vivo evaluation.

First isolation and molecular detection of autochthonous potential probiotic lactobacilli isolates from Iranian traditional Poosti cheese and their antioxidative activity

Introduction: Poosti cheese is an artisanal cheese produced mainly from ewe’s milk in southwest Iran. The objective of this study was to identify lactobacilli isolated from Poosti cheese and to investigate their potential probiotic and antioxidative properties. Materials and methods 101 Grampositive bacilli with catalasenegative reaction were isolated from Poosti cheese. Twenty isolates were selected based on their highest acid and bile salt tolerability. Using genusspecific primers, 10 isolates out of these were identified as Lactobacillus, and they were subsequently identified at species level using 16S rRNA gene sequencing. In vitro tests were used to assess their probiotic properties or antioxidative activities. Results: Six species were Lactobacillus plantarum, and the rest was Lactobacillus paracasei, Lactobacillus acidophilus, Lactobacillus brevis, and Lactobacillus buchneri. The acid and bile tolerances were quantitatively close to the reference probiotic strain. L. plantarum S32E showed the highest survival under simulated gastric or intestinal conditions. Cholesterol reduction ability of L. plantarum S12E and L. acidophilus S37A was significantly higher than that of the reference strain. L. acidophilus S37A and L. plantarum S12E were more susceptible against common antibiotics. It was found that the highest antimicrobial activity was detected in the case of Listeria monocytogenes, and the extent of the activity was species and straindependent. The best result of DPPH radical scavenging activity and hydroxyl radical scavenging activity was achieved by intact cells of L. paracasei S5D and by intracellular cellfree extracts of L. plantarum S8D, respectively. The results indicated that the superoxide dismutase activity of Lactobacillus could not be regarded as an appropriate predictor of antioxidative traits. The highest glutathione content belonged to L. acidophilus S37A and L. parcasei S5D. Discussion and conclusion: Overall, some of Lactobacillus strains of Poosti cheese could be considered as potential probiotic candidates; it should, however, be confirmed by further in vivo evaluation.