Lactobacillus in the Dairy Industry: From Natural Diversity to Biopreservation Resources

Abstract

Biopreservation, defined as the extension of shelf life and enhanced safety of foods by the use of natural or controlled microbiota and/or antimicrobial compounds, is an innocuous and ecological approach to the problem of food preservation and has gained increasing attention in recent years. Fermentation of food by lactic acid bacteria (LAB) is one of the oldest forms of biopreservation practiced by mankind, not only to enhance the hygienic quality but also to minimize the impact of the nutritional and organoleptic properties of perishable food products. Lactobacillus spp. are Gram-positive rod bacteria belonging to the LAB group. Their phenotypic traits, such as homo-/heterofermentation abilities, play a crucial role in souring raw milk and in the production of fermented dairy products such as cheese, yogurt, and fermented milk (including probiotics). Either as starter, as adjunct cultures, or as probiotics, Lactobacillus strains are used as food preservatives not only to prevent the development of food spoilage but also to give consumers a health benefit. Some lactobacilli produce bacteriocins, proteins active against other bacteria. In recent years, the interest in these compounds has grown substantially due to their potential usefulness as natural substitute for chemical food preservatives in the production of foods with enhanced shelf life and/or safety. Bacteriocins can be incorporated directly into fermented foods, or indirectly by using a bacteriocin-producing strain, as a starter or adjunct culture. As the consumers’ interest in natural and healthy foods increases, LAB are currently playing a key role in the development of new products that may respond to this demand.