BIODIVERSITY AND BIOTECHNOLOGICAL POTENTIAL OF LACTIC ACID BACTERIA

摘要

Lactic acid bacteria (LAB) constitute a heterogeneous group of industrially important bacteria that are used to produce fermented foods and beverages, using various substrates, such as milk, vegetables, cereals, meat, cocoa beans etc.The most important advantage of LAB, making them suitable for the use in food biotechnology, is that they are generally recognized as safe (GRAS). LAB have been shown to contribute to the improvement of the shelf life of fermented foods, due to the production of a wide variety of compounds, acting in a synergistic way to prevent or eliminate microbial contamination. In fermented foods, LAB also contribute to the nutritional and organoleptic characteristics of the final products and they are traditionally used as starter cultures for the industrial production of many types of foods and beverages. The so-called "functional foods" concept was recently proposed and has shown a remarkable growth over the last few years. Such foods should promote well-being and health, while at the same time should reduce the risk of some major chronic and degenerative diseases, such as cancer, cardiovascular diseases, obesity and gastrointestinal tract disorders. Therefore, an increasing demand exists for new functional starter strains that show desirable effects on the product characteristics. They should possess at least one inherent functional property, contributing to food safety and/or offering one or more organoleptic, technological, nutritional, or health advantages. Traditionally fermented foods are the best places to look for such microorganisms with potential applications in food industry and health. In Romania, fermented foods are still produced, at a large extent, in a traditional way, depending on local and regional traditions and on the indigenous microbiota present or selected by the environment or technology used (no starter cultures are added). Some of these products, mainly fermented vegetables and cereals are known for their positive effect on human organisms, especially due to the high vitamin and mineral content. The present paper will present our most important findings on the diversity of LAB in traditional Romanian fermented foods, but also on the isolation and characterization of some metabolites produced by these bacteria, with potential applications in food biotechnology.