New lactic acid bacterial strains from traditional fermented foods - bioprotective and probiotic potential

Abstract

In traditionally fermented products, lactic acid bacteria (LAB) strains are related to the organoleptic qualities of the products and their beneficial properties. The present study aims to isolate new strains of LAB from the unique and unstudied microbiota of traditional fermented foods artisanal prepared in the Gora region, Albania, and assesses their potential as antagonists of food-associated microorganisms and as probiotics. Different types of fermented food products (yogurt, white-brined cheese, traditional yellow cheese, dried sausage, and spontaneously fermented fruits) were collected and 12 new isolates were obtained. The new isolates' species identification was performed by morphological, physiological characteristics, and 16 S rDNA gene sequencing. The antibacterial activity of the newly isolated strains was performed and antagonistic effects were shown against E. coli (100 %), B. subtilis (100 %), B. cereus (66.67 %,) and P. aeruginosa (25 %). The antifungal activity is a promising advantage, as all of the strains have shown an established antagonistic effect against A. niger (100 %), A. flavus (91.67 %), F. proliferatum (100 %), and P. claviforme (100 %). They have shown strain-specific aggregation (auto-aggregation, co-aggregation), cell surface hydrophobicity, and mucin adhesive abilities. Strains have the capabilities to grow during the stress conditions like low pH, pepsin, pancreatic enzymes, and bile salts, and survival capabilities were at high levels.