Comparison of Molecular Techniques with other Methods for Identification and Enumeration of Probiotics in Fermented Milk Products

Abstract

Nowadays, an increasing attention is being given to fermented milk products including yogurt, kefir, buttermilk, and acidophilus milk. Fermented milks, especially the ones containing probiotics, are claimed to be useful for health of host (such as intestinal- and immune-associated diseases). Their healthful effects could be significantly enhanced by incorporating probiotic microorganisms; those have healthful advantages for host when consumed in an appropriate viable number in food products. Probiotic dairy products have stepped to the market and are being commercially produced under various brand names. In addition, these products are legislatively obliged to be labeled for the microorganisms contained. Therefore, identification and enumeration of their microorganisms are a cause of concern. Several culture-dependent methods have been introduced and used to identify the microorganisms, in which the researchers have experienced multiple difficulties. Thereby, molecular approaches were present as an alternative, offering advantages such as accuracy, sensitivity, specificity, and speed. This article reviews the molecular approaches employed for identification and enumeration of probiotics in fermented milk products.

Recent Advances in Screening of Anti-Campylobacter Activity in Probiotics for Use in Poultry

“…Identification of probiotic strain at species level is still important as the GRAS (Generally Recognized As Safe) and QPS (Qualified Presumption of Safety) status defined in USA and Europe, respectively, are both based on the species name. Traditional methods for bacterial identification and phenotypical characterization, such as API system, BIOLOG or culture-based techniques can be used to identify probiotics strains (Herbel et al, 2013 ; Bagheripoor-Fallah et al, 2015 ; Galanis et al, 2015 ; Cherdyntseva et al, 2016 ). For instance, the main phenotypic methods for Lactobacillus probiotic identification were discussed in Herbel et al ( 2013 ).…”

“…For instance, the main phenotypic methods for Lactobacillus probiotic identification were discussed in Herbel et al ( 2013 ). However, these conventional microbiological tests may have limitations in discriminating large numbers of isolates with similar physiological characteristics (Herbel et al, 2013 ; Bagheripoor-Fallah et al, 2015 ; Yadav and Shukla, 2015 ). In addition, culture-based techniques provide strains able to replicate under experimental conditions, indeed selective media exist only for a limited subset of potential strains of interest (Davis, 2014 ).…”

“…Several DNA-based techniques have been developed to overcome this obstacle (Bagheripoor-Fallah et al, 2015 ; Yadav and Shukla, 2015 ), such as the pulsed field gel electrophoresis (PFGE) mainly used for probiotic strain differentiation and discrimination (Tynkkynen et al, 1999 ; Gosiewski and Brzychczy-Wloch, 2015 ). However, it cannot be applied for direct detection of a particular strain, in a single reaction (Tynkkynen et al, 1999 ).…”

Common Methods to Understand and Develop Indigenous Probiotics Yeast for Ruminant

“…Extensive use of molecular methodologies may give insights into the new era where such microbial studies are no longer limited to a handful of laboratories with an abundance of funding and labor. It is noted that the specific yeast strains of known origin act more precisely and efficiently as compared to the yeast strain obtained from any unknown origin [60]. As we note all ruminates live in different parts of the world; therefore, upon the ruminal fermentation different yeast strains may exhibit markedly different effects.…”

Rapid identification and quantitation of the viable cells of Lactobacillus casei in fermented dairy products using an aptamer-based strategy powered by a novel cell-SELEX protocol

“…To ensure the functional effects exhibited by L. casei, the amount of the bacterium in food products is a matter of concern. It is generally accepted that viable L. casei has to reach 10 6 cfu/mL(g) as a minimal level and 10 7 to 10 8 cfu/ mL(g) as a satisfactory level to survive the acidic conditions of the upper gastrointestinal tract and proliferate in the intestine (Boylston et al, 2004;Sohrabvandi et al, 2010;Bagheripoor-Fallah et al, 2015). Many dairy drinks containing L. casei are available on the market.…”