Characterization of Nuvita Biosearch Center (NBC) Isolated Lactic Acid Bacteria Strains from Human Origin and Determination of Growth Kinetic Profiles of Selected Cultures by Lab-Scale Bioreactor Fermentation

Backgorund In recent years, there has been an increasing interest in the field of research into the isolation and characterization of probiotics in the prevention of diseases and the need to maintain the continuity of healthy microbiota. Therefore, the aim of this study is to isolate and identify bacteria found in maternal colostrum, breast milk, adult and infant feces, analyze possible probiotic potential, and reveal the developmental kinetics of selected strains. Results We isolated 40 bacterial species from 4 different sources and identified 19 bacteria in the form of bacilli through molecular biology and carried out studies with 11 of them. 5 of the selected strains were showed the better results considering bile salt resistance and ability to survive at different pH, antimicrobial effect. When the adhesion capacity in cell culture was compared, Lactobacillus pontis ZZ6780 and Lactobacillus reuteri NBC2680 came into prominence. Furthermore, the growth kinetics of these strains were demonstrated on a 3 L bioreactor scale. Finally, the growth kinetics of selected strains were determined and the maximum specific growth rate of selected Lactobacillus pontis ZZ6780 and Lactobacillus reuteri NBC2680 was calculated as 0.412 h ^-1 and 0.481 h ^-1 , respectively. In addition, the dry cell matter amounts were found to be and 4.45 g/L and 5.23 g/L, respectively. Conclusion This study established the groundwork for the selection of safety probiotics for the development and application of LAB. It is thought that the two strains obtained as a result of this study can be considered as potential probiotic strains in the food, pharmaceutical and cosmetic industries.