MohammadReza Saeedi Asl; Mehdi Hasan shahiyan; Sara Rashid; Hossein Estiri
Volume 21, Issue 1 , March and April 2015, , Pages 7-16
Abstract
Background: Probiotics are beneficial microorganisms that will be health effects, if be used in a sufficient amount. Due to the growing use of industry dairy, rather than traditional products, there is the possibility of losing a lot of probiotic bacteria. It is, therefore, essential to identify the ...
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Background: Probiotics are beneficial microorganisms that will be health effects, if be used in a sufficient amount. Due to the growing use of industry dairy, rather than traditional products, there is the possibility of losing a lot of probiotic bacteria. It is, therefore, essential to identify the bacteria from traditional sources and use them in the production of dairy products. The aim of this study was to screen and identify Enterococci from KAMEH (a traditional dairy product of Sabzevar), and evaluation of their probiotic potential.
Material and Methods: In this study, sampling was carried out from four different villages. For screening, the collected samples were placed in pH 4.5. The remained strains were evaluated in pH 4 and 0.3 % bile salt. Antimicrobial activity of screened strains was analyzed against Salmonella typhimurium and staphylococcus aureus using disc plate method. Finally, the strains were identified by PCR and sequencing techniques.
Results: The results showed that three different species of Enterococci , including E. faecium, E. avium and E. faecalis, exist in KAMEH, which have a strong probiotic potential, such that they can withstand high levels of acid and bile salts . E1 code had most antimicrobial activity.
Conclusion: This study revealed that KAMEH has Enterococci with appropriate probiotic potential, and can be added as a supplement to other dairy products.
Vahid Koushki; Jafar Vatandost; Seyyed Ali Mortazavi; AliAkbar Jannatabdi; seyyed Abolfazl Hosseini
Volume 20, Issue 5 , March and April 2014, , Pages 726-737
Abstract
Background: Probiotics are beneficial and non-pathogenic microorganisms. Isolation of probiotic bacteria from traditional dairy products can not only lead to the isolation of probiotic bacteria with special characteristics, but it can offer a good approach for the mass production of traditional dairy ...
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Background: Probiotics are beneficial and non-pathogenic microorganisms. Isolation of probiotic bacteria from traditional dairy products can not only lead to the isolation of probiotic bacteria with special characteristics, but it can offer a good approach for the mass production of traditional dairy products containing natural probiotic bacteria.
Materials and Methods: After collection of dairy products samples from different regions of Sabzevar, they were continuously cultured on the specific media of MRS and MRS Broth. Initial identification of isolates was performed by gram stain, motility test, nitrate reduction test, growth at 15 and 45 °C, growth at pH: 9/6 and fermentation capability of 11 different sugars. To identify desired strains more precisely, the 16S rDNA gene was amplified by PCR with specific primers and then sequenced and BLASTed. Acidic and bile salts conditions tolerance tests were performed for the final confirmation of desired strains.
Results: After continuous culture on specific agar media, 16 strains for further analysis were selected. In early identification of isolates by phenotypic methods, 14 strains were positive. To identify these strains more precisely, the 16S rDNA gene was amplified. Following molecular identification and sequencing of 16S rDNA gene, the BLAST sequence similarities were found with Lactobacillus planetarium. In addition, acidic and bile salts conditions tolerance tests showed that these bacteria had the best growth pattern at PH: 4 and they were able to grow in the presence of bile salts.
Conclusion: Biochemical results showed that the most common strains in the tested dairy products are Lactobacillus. These results also confirmed by the molecular tests. Acidic and bile salts conditions tolerance test, as a main characteristic of probiotic bacteria, showed that the strain was able to withstand these conditions.