Isolation and characterization of novel bacterial strains for the development of fermented health-promoting plant-based products

In recent years, interest in fermented plant-based products has grown significantly due to the benefits that fermentation provides to nutritional, sensory, and bioactive profiles of final products. Nevertheless, bacterial strains currently used for fermentation are mainly derived from dairy products and may face challenges when adapting to plant-based substrates. This highlights the need to identify novel bacterial strains specifically adapted to plant matrices, capable of improving fermentation efficiency. Along this line of research, this project aims to isolate and characterize new bacterial strains suitable for fermenting plant-based beverages, aiming to create products with optimal properties. After inoculating different plant-based drinks with the brine of homemade fermented vegetables, LAB strains were isolated. The strains underwent safety tests (antibiotic resistance, biogenic amine and D-lactic acid production). Strains considered safe for human consumption were used to ferment a soy-based beverage and assessed for growth, texture modification, and sugar utilization. Additionally, their phytase and protease activities were measured, along with their ability to convert glycosylated isoflavones into bioavailable aglycones and to alter the estrogenic activity of these compounds. Strains (belonging to the species Lactiplantibacillus paraplantarum, Lactiplantibacillus plantarum, Lactococcus lactis, Leuconostoc pseudomesenteroides, Leuconostoc mesenteroides, Levilactobacillus brevis, and Loigolactobacillus coryniformis) that exhibited the most favorable characteristics were selected. In conclusion, this project highlights the potential of tailoring fermentation processes to plant-based substrates, overcoming the limitations of traditional dairy-derived cultures. This paves the way for the development of innovative and health-promoting plant-based fermented beverages that meet the growing demand for alternative protein sources.