The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective

Lactic acid bacteria (LAB) are essential dairy starter cultures that are significantly employed for the manufacture of fermented dairy products such as yogurt and cheese. LAB predominantly produce lactic acid as a major end product of fermentation, and they synthesize important metabolites that impart the organoleptic characteristics of fermented food products. LAB are fastidious bacteria that thrive in many environments when adequate nutritional requirements are fulfilled. The demand for superior LAB dairy starter cultures for fermentation applications in the food and dairy industry, has resulted in the need to provide viable and active cultures for all bioprocessing operations. The development of a standard protocol for ensuring the viability and enhanced functionality of LAB cultures in the laboratory as well as dairy processing environments is thus very critical. In addressing concerns linked to resuscitating weak, stressed, and injured LAB culture cells, a protocol that vividly outlines salient steps to recover, enhance cell regeneration, and improve metabolic functionality of LAB strains is of the utmost importance. The maintenance of culture purity, functionality, and viability for LAB starter cultures is likewise critical. Therefore, adherence to a unique protocol guideline will result in the promotion of fermentation performance for many LAB strains dedicated to fermentation and biotechnology processes. As a result, the Food Microbiology and Biotechnology Laboratory at North Carolina Agriculture and Technical State University has developed a standard protocol for the activation and quality control of selected LAB strains that has resulted in highly functional and viable LAB culture strains employed for fermentation research. The adaptation and recommendation of a protocol such as this for use in the dairy and food industry will help to ensure LAB viability and functionality for many applications.