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Quick lactobacillus acidophilus quantification in probiotics using real-time PCR

Pham Thi Le Quyen Pham Nhu Trong Nguyen Thuy Linh Nguyen Thanh Trung
Received: 25 Dec 2018
Revised: 25 Jan 2019
Accepted: 05 Feb 2019
Published: 28 Feb 2019

Article Details

How to Cite
Pham Thi Le Quyen, Pham Nhu Trong, Nguyen Thuy Linh, Nguyen Thanh Trung. "Quick lactobacillus acidophilus quantification in probiotics using real-time PCR". Vietnam Journal of Food Control. vol. 2, no. 1, pp. 2-8, 2019

Main Article Content


Lactobacillus has a biological effect to supports digestion system. Therefore, it is widely used in dairy products such as yoghurt, food additives and pharmaceuticals. Lactobacillus acidophilus (L. acidophilus) is often used in fermented dairy products such as yoghurt and functional products. However, in Vietnam, there is currently no standard method for quantifying L. acidophilus. In this study, a quantitative method of L. acidophilus using real-time PCR based on a specific fragment of Hsp gene was developed. The limit of quantification of the method is 105 CFU/g/mL that is suitable for quality assessment of probiotic products with greater quality claims than 106 CFU/g/mL. The specificity of the method is of 100% when compared with nonspecific strains and repeatability is of Sr < 0.125 in accordance with the requirements of ISO 16140: 2005 and AOAC: 2016 annex F for method evaluation microbiology.


Lactobacillus acidophilus, Real-time PCR, probiotics


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