Molecular Methods for Detecting Microorganisms in Beverages

Abstract

Beverages are an integral component of a person’s food package. Various types of microorganisms widely contaminate beverages. This review presents current research data aimed at identifying dominant microorganisms in beverages and molecular methods for their detection. Wine, beer, dairy drinks, and fruit juices were selected as the main objects of the study. The most contaminated beverage turned out to be fruit juice. As a result of a large number of independent studies, about 23 species of microorganisms were identified in it. At the same time, they are represented not only by bacterial and fungal organisms, but also by protozoa. Milk turned out to be the least contaminated in terms of detected bacteria. The most common pollutants of these beverages were Staphylococcus aureus, Bacillus cereus, and Vibrio parahaemolyticus. It has been established that among pathogenic genera, Salmonella sp., Campylobacter sp. and Shigella sp. are often present in beverages. One of the main tools for the quality control of beverages at all stages of their production is different types of polymerase chain reaction. The sequencing method is used to screen for microorganisms in beverages. The range of variations of this technology makes it possible to identify microorganisms in alcoholic and non-alcoholic beverages. The high specificity of methods such as PCR-RFLP, Rep-PCR, qPCR, End-point PCR, qLAMP, the molecular beacon method, and RAPD enables fast and reliable quality control in beverage production. Sequencing allows researchers to evaluate the microbiological diversity of all the studied beverages, while PCR varieties have demonstrated different fields of application. For example, PCR-RFLP, RAPD-PCR, and PCR allowed the identification of microorganisms in fruit juices, qPCR, LAMP, and the molecular beacon method in wine, LAMP and multiplex PCR in milk, and End-point PCR and Rep-PCR in beer. However, it is worth noting that many methods developed for the detection of microbial contaminants in beverages were developed 10–20 years ago; modern modifications of PCR and isothermal amplification are still poorly implemented in this area.

Keywords

• beverages
• contamination
• bacteria
• pathogens
• PCR
• sequencing