Probiotics are recognized as live microorganisms that confer a health benefit to the host when administered in adequate amounts. The present study aimed to evaluate in vitro probiotic properties of two commercial probiotic strains, Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus plantarum ATCC 14917. Our results indicated that the selected strains showed high resistance to acid, bile salts, and lysozyme. In general they showed good adaptation to simulated gastric and intestinal juices (more than 85% could survive) which guarantees their survival in the gastrointestinal tract. Moreover, Bifidobacterium animalis subsp. lactis BB-12 showed the highest hydrophobicity (59.75%) and auto-aggregation (51.42%) but the lowest adhesion to the human intestinal HT-29 cell line (8.35%). Furthermore, they both had β-galactosidase activity and were resistant to penicillin, vancomycin, and tetracycline. Our results indicated that Lactobacillus plantarum ATCC 14917 had better characteristics of a probiotic compared to Bifidobacterium animalis subsp. lactis BB-12.

Evaluation of probiotic properties of lactic acid bacteria (LAB) isolated from fermented pseudocereals has crucial importance to prepare microbial cultures. In the present study, after molecular identification, probiotic properties of the predominant LAB isolate were investigated. Sequencing results of the PCR products led to the identification of Lactobacillus brevis SKA01 as the predominant LAB. The survival of the LAB isolate after continues treatment of acid and bile reached to 106 compared to the control sample (108 CFU/mL), and it showed the highest antibacterial effect on Staphylococcus aureus. Meanwhile, there was no significant difference (P>0.05) between inhibitory zone diameter of the S. aureus and Listeria monocytogenes in the present of the LAB isolate.  LAB isolate was capable of good auto-aggregation (36.19%) and co-aggregation with S. aureus (71.24%), and it had no hemolytic activity. Furthermore, it was resistant to most of the tested antibiotics. By considering the proper probiotic potentials of the L. brevis isolated from fermented amaranth, it is possible to use the isolate as microbial starter or probiotic culture in fermentation industries.

European honey bees (Apis mellifera) are the most important pollinator insects that play vital role in maintenance of all most all life forms on earth. However, over the last decade major concerns have raised due to decline in the population of these insect species. A variety of factors have been responsible for these concerns of which the most important is honey bee bacterial diseases like Nosemosis (Nosema), American and European foulbrood diseases. While, overuse of antibiotics utilized for the treatment and control of these diseases has resulted in the emergence of antibiotic resistant strains of these pathogens. Probiotics have been considered a suitable substitute of antibiotics in human and animals. In last several years, lactobacillus species isolated from honeybees have been considered of significance in enhancing the life span of honeybees by reducing the incidence of bacterial and viral infections in these tiny insects. Among the isolated microbes in the gut of honeybees, Lactic Acid Bacteria (LAB) are of utmost importance showing direct impacts on the health of their host by modulating the gut microbial flora and are termed as Probiotic bacteria.The objective of this research was to isolate and identify LAB from different parts of the intestinal tract of honeybees Apis mellifera and to characterize their probiotic properties.

Twenty-four honeybees collected from the hives located in the city of karaj were analyzed for the presence of LAB species. The stomach contents of honeybees were inoculated into MRS broth, incubated at 37ºCfor 48 hrs. The obtained colonies were purified and identified to species levels phenotypically and geno-typically. Hemolytic activity and sugar fermentation reactions of the isolates were recorded and later subjected 16SrRNA sequencing using a pair of universal primers. The identified isolates were evaluated for their viability in acidic conditions at pH 2.5, 3.0, 4.0 and 6.5 at different time intervals. Bile resistance of the isolates was tested by culturing the isolates in the presence of different concentrations of the said salts (0.5, 0.7 and 1%). Survival of LAB isolates in simulated gastric and intestinal conditions containing different enzymes and bile salts, antibacterial spectrum against a number of gram positive and gram-negative pathogens by agar well diffusion assay, and their in vitro colonization ability (aggregation, co-aggregation and hydrophobicity percentages) were evaluated. The results were analyzed statistically.

Twenty nine gram positive, catalase negative and non-hemolytic colonies were isolated from 24 honeybee samples. Among these, only 7 colonies showed enhanced antibacterial activity and were selected for further studies. Based on phenotypic characteristics, sugar fermentation reactions and 16S rRNA sequencing the isolates were identified as Lactobacillus acidophilus (1), Lacticaseiobacillus casei, Lactiplantibacillus plantarum (2), Lactobacillus apis (1), Enterococcus faecium (1) and Pediococcus acidilactici (1). During probiotic characterizations, the identified isolates were shown to retain their viability in acidic conditions and resisted pH 2.5, 3 and 4 for more than 4 hrs. However, slight decrease in viability at pH 2.5 and 3.0 was observed, compared to pH 4.0 and above. All isolates appeared bile resistant and tolerated all used concentrations of bile salts during 8 hrs of incubation. Survival rate of the isolates in simulated intestinal conditions was significantly (p˂0.05) greater compared to simulated gastric conditions indicating greater stability of the isolates to alkaline conditions rather than to acidic conditions. L.acidophilus and E.faecium showed least resistance in gastric conditions and their growth rate was decreased more than 50% under said conditions. In contrast, the growth rate of these two isolates was highest in simulated intestinal conditions as they resisted these conditions for more than 24 hours.  The isolates demonstrated antibacterial affect against a number of tested pathogens including Listeria monocytogenes, Escherichia coli, Enterococcus faecalis and Streprtococcus mutans. The auto-aggregation, and cell surface hydrophobicity percentages of L.casei appeared highest compared to other tested Lactic Acid bacteria in study (p˂0.05), while, L.apis showed the highest co-aggregation with S.typhi strain. P.acidilactici possessed the least auto-aggregation (46%), co-aggregation (10%) and hydrophobicity (43%) percentage. Auto-aggregation ability appeared directly related to hydrophobicity percentages and isolates showing high aggregation ability also showed high hydrophobicity %.

In conclusion, honeybee gut appeared a reservoir of LAB with probiotic potential. It is suggested that further studies should be conducted in order to determine the health benefits of these LABs in honeybees, with especial emphasis on their ability to prevent honeybee diseases.

Probiotic and antifungal properties of the yeasts isolated from fermented pseudo cereals have been rarely studied, yet. In the present study, after isolation of predominant yeasts isolated from fermented black rice, the yeast with the highest survival in simulated gastrointestinal conditions was selected for further studies. Then, the selected isolate was identified by PCR, and subsequently, its probiotic properties including antibacterial effects, antibiotic and antimycotic susceptibilities, aggregation, hydrophobicity and hemolytic potentials were also studied. Antifungal activity of the selected yeast was investigated against some of the foodborne fungi. Sequencing of the PCR products led to the identification of Rhodotorula mucilaginosa as the selected yeast isolate. The isolate maintained 84.39% of its survival in continues acid and bile treatment. Also, the inhibitory effect of the yeast isolate on Salmonella enterica was significantly (p<0.05) higher than the other foodborne bacteria. Yeast isolate had proper aggregation and hydrophobicity capabilities, and it was resistant to the antibiotics tested. Furthermore, the most inhibition of the yeast growth was observed in the presence of ketoconazole, while the selected yeast was resistant to propionate, sorbate, itroconazole and fluconazole. The studied yeast isolate had no hemolytic activity. The antifungal effect of the yeast isolate against Aspergillus flavus was also verified. In accordance with these results, the selected yeast isolate has a proper potential to use as a probiotic or protective culture in production of fermented foods.

Nowadays, the increase in diseases and the appearance of antibiotic-resistant bacteria has urged researchers to increase the nutritional health of society by applying new methods and benefiting from useful microorganisms, including probiotics. Therefore, the isolation and identification of beneficial microorganisms with probiotic properties has been important for increasing health among people. The most important probiotic bacteria are the genus Lactobacillus. In this study, Lactobacillus brevis strain PML1's probiotic properties have been evaluated. The tolerance of bile salts, antibiotic resistance, the ability to control pathogens, and the hydrophobicity properties of the strain have been studied. Then, in the complementary assay, the adhesion ability to Caco-2 cells, the survival in gastrointestinal simulated conditions are evaluated. The results show that the strain has a high potential for survival in bile salts of the intestine. The percentage of hydrophobicity of strain was 18/33%. Adhesion rates for Caco-2 cells were 13.8%, also L. brevis strain PML1 showed a high ability to prevent the pathogenicity of adhesion (35.5%). According to the results of the L. brevis strain PML1 has a relatively suitable probiotic potential. Therefore, it is recommended to use this strain as a probiotic supplement in fermentative cultivations or as a co-cultivation in the fermentation process of various foods.

Probiotics and especially Lactobacilli are among the most important components widely used in food technology. Isolation and characterization of indigenous probiotics should be performed in native populations. In order to isolate lactobacillus spp. from Iranian traditional Lighvan cheese to be used as starters, 15 cheese samples were randomly selected and tested for technological and probiotics properties. Lactobacilli were characterized using culture-based and bio-chemical techniques and results were verified using PCR analyses of the 16S rRNA region. The probiotic characteristics of these bacteria were studied by acid and bile tolerance. The susceptibility of different isolates against a number of important antibiotics was tested. The technological traits of LAB were assessed using measurement of acid production and analyzing salt tolerance. The isolates were also screened for proteolytic and lipolytic activity. Of the 12 samples containing Lactobacilli, 10 belonged to L. plantarum while 2 were close to L. bulgaricus spp. All isolates were tolerant to 3% NaCl and 9 tolerated 6-8% NaCl. Almost all isolates were lipase-positive at 37 °C and 30 °C. Nine Lactobacilli were shown to be protease-positive at 37°C. Two isolates were completely tolerant to pH 1.55, 4 had intermediate resistance, 4 were of weak resistance and 1 was sensitive. All but one isolate were tolerant to 0.03% bile acid. Some isolates were shown to be sensitive to erythromycin, ampicillin, tetracycline, amikacin and rifampicin. Results indicate that most of the isolated Lactobacilli can be used as industrial cheese starters and/or as native probiotics in production of functional foods.

Probitics are dietary supplement of live microorganisms which confer a health benefit on the host when administrated in an adequate amount in the gastrointestinal system. Lactic acid bacteria (LAB) are the most common type of microbes used as probiotics. Following significant developments in the dairy industry and an explosion in interest in the use of probiotics as functional foods, probiotic dairy products look at advancements in the dairy industry. Traditional yogurts and cheeses have long been considered an ideal vehicle for delivering probiotic bacteria to the human gastroinstestinal tract which explains the widespread use of probiotic cultures in dairy products. Two regions, Heris and Sarab, have traditional dairy products that may be source of many LAB.The aim of this study was to identify and isolate potentially probiotic bacteria from traditional cheese and yoghourt of Heris and Sarab regions. To achieve this goal, LAB were isolated and characterized using phenotypic methods (Gram staining, physiological and biochemical tests). Then their acid and bile tolerance, as the primary probiotic characteria, were investigated. 16s rRNA gene of lactobacilli and Enterococci was amplified for identification of bacterial strains. Genotyping of isolates was performed by RAPD-PCR analysis using four randomly primers.At the end of the study, 15 lactobacillus spp. and 16 Enterococcus spp. were isolated from traditional dairy products of these regions that could be potentially used in the industrial dairy products.

Probiotic are live microbial food supplement which bestows beneficial effects on the host by creating intestinal microbial balance. In this research, we aimed to identify locally isolated LAB with probiotic potentials by phenotypic and genotypic methods.
Material and A number of locally isolated LAB identified by phenotypic characteristics were selected and screened for their probiotic properties. The isolates were tested for their acid and bile resistance, antibacterial activity, cholesterol reducing. The selected probiotic LAB were identified to species level by using universal primers and 16S rRNA sequencing.
Among the 20 LAB isolates, only 3 isolates resisted low pH value of 2.5, while 5 isolates resisted 0.3 to 1% bile salt. Among these 5 isolates, 3 isolates showed the ability to lower cholesterol significantly as they reduced 94.8, 95.73 and 97.82 % of cholesterol within 2 hours of incubation. All isolates except for 24SN hydrolyzed bile salt. Based on 16S rRNA sequencing these 5 isolates were identified as Lactobacillus plantarum (22SN, 24SN, NPN0022, 10SN), and Lactobacillus rhamnosus (30SN).
The LAB isolates in this study possessed significant probiotic properties and might be used as a probiotic in human, livestock, and poultry products in the future.

Probiotics as replacement for growth promoter antibiotics and foodborne pathogens bio-control strategy are attractive in broiler chicken industry and improve consumer food safety. This research was designed to investigate the probiotic properties of lactic acid bacteria isolated from the digestive tract of local domestic chickens in Iran. In this study, the ability to tolerate acid and bile in two 216 isolates of lactic acid bacteria was investigated and 13 superior isolates were selected to be identified using the 16 S rRNA gene sequencing. After that, the ability of 13 selected lactobacilli isolates to control foodborne pathogens was studied. The results of the 16S rRNA gene sequencing showed that all isolates belonged to the Lactobacillus species. Of the 13 isolates, 7, 3 and 3 isolates belonged to Lactobacillus reuteri, Lactobacillus crispatus and Lactobacillus salivarius, respectively. All of these isolates were able to tolerate pH = 3 for 3 hours and 0.3% bile salts. Three isolates belonging to L. salivarius were more effective to inhibit common Zoonoses bacteria. This study revealed that the in vitro favorable probiotic potential in some isolated lactobacilli from the native chicken digestive tract from Iran, introduce them as good candidates in probiotic supplements to improve food safety of consumer after conducting in vivo tests.