High folate production by naturally occurring Lactobacillus sp. with probiotics potential isolated from dairy products in Ilam and Lorestan provinces of Iran

Rapidly proliferating cells require large amounts of folate to support efficient DNA replication, repair and methylation indicating the importance of folate in human metabolism. Milk products are good sources of such vitamins which are produced by probiotics. In order to find suitable strains capable of high folate production, isolation and identification of Lactobacilli in traditional fermented milk from two different provinces located in the west of Iran were carried out. Lactobacillus  bacteria were isolated according to the ISO 7889 standard procedure. The isolated bacteria were characterized phenotypically and were screened for their ability to produce folate during fermentation of skim milk. Folate production by the selected strains was between 2.8 to 66.6 μg/l. Two strains with the highest folate production were then selected. The 16SrRNA genes from these two strains were amplified and sequenced and a phylogenetic tree constructed. The sequencing results in combination with phenotypic and biochemical properties showed that both strains were similar to Lactobacillus crustorum. Therefore, two new strains with an ability of high folate production were isolated and identified. These could be used as probiotics in the dairy industry. Hence, exploiting natural food-grade microorganisms for the production of nutritive dairy products is possible.Keywords: Folate, Lactobacillus, probiotic, traditional dairy products, IranAfrican Journal of Biotechnology Vol. 9(33), pp. 5383-5391, 16 August, 201

Comparison of the Chemical Compositions and Antibacterial Activities of Two Iranian Mustard Essential Oils and Use of these Oils in Turkey Meats as Preservatives

Background and objective: Iranian mustard is cultivated in southern areas of Iran and used traditionally as natural preservative. Aims of the current study were identification and comparison of the chemical compositions and antibacterial activities of two Iranian mustard essential oils and assessment of these oils use for increasing the shelf life of turkey meats.Material and methods: Chemical compositions of two Iranian mustard essential oils were identified using gas chromatography-mass spectrometry and antibacterial activities of these oils were assessed against Salmonella typhimurium, Escherichia coli, Citrobacter freundii, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus and Enterococcus faecalis using disc diffusion and broth macrodilution assays. Inhibitory effects of the essential oils were assessed on growth of mesophilic psychrotrophic bacteria, yeasts and molds and sensory evaluation was carried out for the turkey meats.Results and conclusion: Results of GC-MS showed presence of bioactive constituents, especially allyl isothiocyanate (75.87-80.07%). All the bacterial growth, especially for Escherichia coli, was inhibited with inhibition zones of greater than 20 mm and minimum inhibitory and bactericidal concentrations of 0.156 mg ml-1. Treatment of turkey meat samples with the mustard essential oils significantly decreased the count of mesophilic psychrotrophic bacteria, yeasts and molds during 20 days of storage at 4°C ±1, compared to controls (P≤0.05). Over the time, the sensory score of the treated samples increased, compared to controls. Based on these findings, the Iranian mustard essential oils can be used as natural preservatives in foods.Conflict of interest: The authors declare no conflict of interest