Traditional fermentative dairy products are complex ecosystem of lactic acid bacteria and because of this microbial variety, direct isolation of probiotic from traditional dairy products is very complicated operation. Aim of this study was to selective screening of potential probiotic lactobacilli from traditional dairy products including yoghurt, cheese, and dried whey without passing through preliminary time consuming isolation steps. In this study, 30 different samples of diary products were prepared from traditional workshops and following the delivery to laboratory in 4oC, they carried to MRS broth that is considered as a suitable nutritive medium for incubation of lactobacilli. In order to increase the possibility of probiotic bacteria growth, dairy samples went through an acidic treatment and then the species sensitive to acidic condition were omitted and the isolates which were resistant to acid and bile salts were separated on a MRS agar medium containing 1% bile salts. Following the warm coloration and catalase test, the positive warm bacilli and lactobacilli negative catalase were identified and stored under glycerol in -70oC and their resistance to acidic condition and bile salts were evaluated.Finally, from among 30 different dairy samples, 19 lactobacilli species which had the highest resistance to acidic condition and bile salts were chosen as the potential probiotic species.

rural areas around Naein, Iran in sheepskin bags. The present study aimed to isolate Lactobacillus bacteria from the traditional dairy products of Naein and to evaluate the functional characteristics and health of these bacteria as probiotics. Materials and Methods: For the initial isolation of bacteria, de Man, Rogosa, and Sharpe (MRS) agar was used. A total of 15 bacilliform, gram-positive, and catalase-negative colonies were isolated from the culture, and resistance to acid, bile, gastric juice, and intestinal juice was assessed to investigate probiotic characteristics. Bacterial isolates with favorable probiotic characteristics were tested for antimicrobial activity and antibiotic resistance to assess the effect of probiotics on health. Afterwards, seven bacterial isolates were selected and their ability for reducing cholesterol and hydrolyzing bile salts was evaluated. Moreover, the selected isolates were sequenced to identify the strain. Results: Our findings demonstrated that six of 15 bacterial isolates had a suitable resistance in pH=2. 5. In addition, 60% of the isolates were sensitive to bile salts. The identified Lactobacillus isolates had a high antibiotic resistance and were shown to have a favorable antimicrobial activity against pathogenic bacteria. Furthermore, the selected bacterial isolate could reduce 70% of environmental cholesterol. Conclusion: According to the results of the present study, koome is highly potential for isolating probiotic isolates and the nutritional consumption of Lactobacillus isolates s microbial supplement might have positive effects on health.

Background: Inhibition of biofilm formation is essential for the prevention and treatment of urinary tract infection. This study was aimed to identify the probiotic potential of Lactobacillus strains isolated from kefir and evaluate their antimicrobial and antibiofilm activities against Uropathogenic Escherichia coli (UPEC). Methods: Twelve Lactobacillus strains were evaluated. Antimicrobial and antibiofilm activities of Cell Free Supernatant (CFS) of the Lactobacillus strains against UPEC isolates were evaluated by agar well diffusion method and crystal violet assay, respectively. Probiotic potential of selected isolates was assessed by analyzing their tolerance to acidic pH and bile salts, auto-aggregation ability, co-aggregation with Escherichia coli (E. coli) and hemolytic activity. The isolates were identified by phenotypic and 16S rRNA gene sequencing. Results: The CFS of all lactobacilli strains was able to inhibit UPEC isolates even after neutralization. Four out of 12 isolates inhibited the biofilm formation by UPEC in the range 62-75%. The viability under acidic condition varied among the isolates ranging from 6-89. 8%. All the isolates could tolerate the 0. 3% bile and eight isolates showed the adaptation time of less than 1 hr. All the strains exhibited co-aggregation with E. coli. Auto-aggregation was highly correlated with co-aggregation of all lactobacilli strains with E. coli (r=0. 889, p<0. 001). The isolates with satisfactory probiotic potential and higher ability of biofilm inhibition and antibacterial activity belonged to the species Lactobacillus rhamnosus and Lactobacillus paracasei. Conclusion: All four selected probiotic strains exhibited antimicrobial and antibiofilm activities, which suggest potential applications for controlling or preventing infections caused by UPEC.

Background: For biotechnological application, selected lactic acid bacteria strains belonging to the genera Lactobacillus(Lb) are proposed as an alternative to the antibiotics for the prevention and treatment of urogenital tract infections.Objectives: Isolating and selecting vaginal lactobacilli strains for probiotic use based on their technological and probioticaptitudes.Materials and Methods: The vaginal isolates were examined for their essential characteristics as the potential probioticsuch as low pH tolerance, bile-salt and simulated human intestinal fluid (SIF) resistance, adhesion to the vaginal epithelialcells (VECs), aggregation and coaggregation, surface hydrophobicity, antimicrobial activity, acid production, antibioticresistance, and resistance to spermicides. The best strain was identified by PCR.Results: From 70 lactobacilli isolates and according to the 16 rDNA sequences, isolates B6 and B10 showed the closesthomology (99%) to the Lb. gasseri and Lb. plantarum respectively. They produced hydrogen peroxide (H2O2), tolerant toacid, bile, simulated human intestinal fluid, present a strong adhesion, highest percentages of aggregation, and antibacterialactivity. These strains are resistant to the spermicide and actively acidify the growth medium.Conclusions: Strains Lb. plantarum B10 and Lb. gasseri B6 have a strong potential probiotic confirming their value as atool for prevention against urinary and vaginal infections.

Background: Nickel is a major pollutant of water and food, playing a destructive role in the health disorders of humans. Recently, probiotic bacteria have been recognized as a highly secure and eco-friendly approach to nickel biodetoxification. Methods: Four lactobacillus strains, namely L. brevis 205, L. mucosae 226, L. plantarum 78, and L. casei 303 were investigated to assess their nickel resistance through disk diffusion and MIC methods. Strains with the highest and lowest resistance were selected for Bioremediation assays including Biosorption, Desorption, and Bioaccumulation. Results: L. brevis 205 and L. casei 303 exhibited the highest and lowest sensitivity to nickel, respectively. Both of them exhibited a plentiful performance in Biosorption assays, with 82. 22% for L. brevis 205, and 72% for L. casei 303. The bioremoval assay with the para-probiotic (dead) biomass of the two strains exhibited a Biosorption yield of about 69% for L. brevis 205 and 75% for L. casei 303. Conclusion: both probiotic and para-probiotic biomass demonstrated excellent nickel Biosorption capability and L. casei 303 para-probiotic biomass outperformed L. brevis 205. Thus, probiotic Lactobacillus strains of this study could be brilliant candidates for nickel bioremoval in water, food, and pharmaceutical industries, regardless of bacterial resistance or viability.