Lactic Acid Bacteria: Taxonomy, Characteristic Features, Physiology, and Diversity

The versatility of lactic acid bacteria (LAB) makes their use significant for the health and food industries. These bacteria belong to the phylum—Firmicutes, class—Bacilli, and order—Lactobacillales, and are known to convert sugars into lactic acid, thrive in low pH environments, and withstand challenging conditions. These characteristics contribute not only to their probiotic features, but also to their role in fermenting foods, where their metabolic capabilities, including acidification and bacteriocin production, aid in preservation and flavor development while inhibiting potential pathogens. With over 200 identified species spanning multiple genera, LAB exhibit diverse physiological traits and functional properties, making them a subject of interest for researchers and industries. This chapter provides an overview of LAB’s taxonomy, characteristics, physiology, diversity, environmental adaptability, contributions to human health, and their crucial role in fermented foods production.