Probiotics Viability Test

The number of live probiotics may affect the effectiveness of a probiotic product and is one of the important attributes in evaluating a probiotic product.

Creative Enzymes offers a variety of methods to accurately measure the number of live bacteria in probiotic products to help our clients effectively assess the quality of their probiotic products.

Why Live Bacteria Testing is Necessary

• Probiotics have a beneficial effect on the health of the host when consumed in sufficient amounts. Therefore, "activity" is an important characteristic of probiotics.
• The stability of live bacteria type probiotic health food is stipulated to ensure that the number of live bacteria should not be less than 10^6 CFU/mL(g) during its shelf life.
• The number of live bacteria in a probiotic product is a crucial parameter for producers, consumers, and regulators alike.

Live Bacteria Testing Methods Provided by Creative Enzymes

Creative Enzymes provides clients with a variety of validated assays for detecting the number of live bacteria in probiotic products. These methods have wide application in the determination of the number of live bacteria in probiotic products.

Plate Counting Method

The colony plate count method is an isolation culture-based test. The method usually requires appropriate serial dilutions of the test sample. An amount of the dilution is applied to the plate for incubation and colony forming units (CFU) are counted to obtain an estimate of the number of viable bacteria present.

Gene Expression Activity Based: qPCR

The transcriptome can reflect the viability status of microorganisms. Creative Enzymes uses RT-qPCR technique to select the mRNA of specific genes of microorganisms as detection targets, and by this method, the number of viable bacteria in the samples is determined.

To improve the accuracy of the mRNA-based detection method, we combined RT-qPCR with techniques such as propidium azide staining (PMA, which selectively labels dead cells) and 16S rRNA sequencing to set up a positive control group for dead bacteria to distinguish live bacteria.

Flow Cytometry Sorting Technology

Creative Enzymes uses flow cytometry sorting technology to count the number of viable bacteria on the basis of staining or fluorescent labeling. Flow cytometric sorting and counting is a modern cell analysis technique for efficient qualitative or quantitative detection. Subpopulations of luminescent particles can be separated according to the fluorescence intensity and wavelength of the emitted light, and monoclonal sorting can be achieved to sort, quantify and separate cells in complex samples.

We offer flow cytometry technology that allows the detection of large numbers of bacteria at once, sorting of different bacteria, and detection of different physiological activity and bacterial size of live bacteria.

Raman Spectroscopy Detection

Creative Enzymes exploits the difference in surface charge between live and dead bacteria, and tests the Raman enhancement signal of live bacteria by adsorbing silver ions on their surface and then reducing them. The results show that the fully inactivated bacteria have almost no Raman enhancement signal, while the Raman enhancement signal on the surface of the live bacteria, is very rich, as a way to identify the live bacteria.

Fig. 1 Scheme of the single-cell laser tweezers Raman spectroscopy (LTRS) setup. (Lu, 2020)

Other Methods: Products of Bacteria

Creative Enzymes also provides some novel detection methods. Using substances secreted or gases emitted by probiotic bacteria during growth and fermentation as biomarkers, the number of live bacteria can be indirectly determined by detecting the amount of secretion or gas produced by live bacteria.

Potential secretions that can be used for viable bacteria detection are: type III secretory protein SpaO, protein precursor translocase, etc.

Creative Enzymes is a professional and experienced probiotic supplier and service provider. We are committed to providing total solutions for our customers' probiotic product research. To get more information, please contact us or fill out the online inquiry below, we will be happy to serve your research demands.

Reference

1. Lu, W.; et al. Combination of an artificial intelligence approach and laser tweezers Raman spectroscopy for microbial identification. Analytical chemistry. 2020, 92(9): 6288-6296.