Lactic acid bacteria isolated from dairy products as potential producers of lipolytic, proteolytic and antibacterial proteins

• Published in: Applied microbiology and biotechnology Vol. 103; no. 13; pp. 5243 - 5257
• Main Authors: García-Cano, Israel, Rocha-Mendoza, Diana, Ortega-Anaya, Joana, Wang, Karen, Kosmerl, Erica, Jiménez-Flores, Rafael
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2019; Springer; Springer Nature B.V
• Subjects: Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Bacteria; Biomedical and Life Sciences; Biosynthesis; Biotechnologically Relevant Enzymes and Proteins; Biotechnology; Cultured Milk Products - microbiology; Dairy products; Dairy Products - microbiology; Digestibility; Digestive system; Digestive tract; Dysbacteriosis; Enzymatic activity; Enzymes; Escherichia coli - drug effects; Fatty acids; Fermentation; Fermented food; Food; Food Microbiology; Gastrointestinal system; Gastrointestinal tract; Intestinal microflora; Lactic acid; Lactic acid bacteria; Lactobacillales - enzymology; Lactobacillales - isolation & purification; Life Sciences; Lipase - isolation & purification; Lipase - metabolism; Lipolysis; Methods; Microbial Genetics and Genomics; Microbiology; Microbiota; Microorganisms; Peptide Hydrolases - isolation & purification; Peptide Hydrolases - metabolism; Physiological aspects; Production processes; Proteins; Proteolysis; Staphylococcus aureus - drug effects; Strains (organisms); Zymography; Lactic acid bacteria; Dairy products; Bioactivity
• ISSN: 0175-7598; 1432-0614; 1432-0614
• DOI: 10.1007/s00253-019-09844-6

Regular consumption of fermented dairy products helps maintain a healthy microbiota and prevent gut dysbiosis-linked diseases. The lactic acid bacteria (LAB) present in food enhance the digestibility of proteins, moderate the release of fatty acids, and support human health through inhabiting the gastrointestinal tract. These desirable properties of LAB are attributed, in part, to their metabolic processes involving enzymes such as lipases, proteases, and antibacterial proteins. The LAB strains presenting higher enzymatic activities may offer improved functionality for applications in foods. The first aim of this work was to isolate and identify LAB from diverse dairy products and select those with enhanced enzymatic activities. Secondly, this work aimed to investigate the subcellular organization and identity of these enzymes after semi-purification. Out of the total 137 LAB strains isolated and screened, 50.3% and 61.3% of the strains exhibited lipolytic and proteolytic activities, respectively. Seven strains displaying high enzymatic activities were selected and further characterized for the cellular organization of their lipases, proteases, and antibacterial proteins. The lipolytic and proteolytic activities were exhibited predominantly in the extracellular fraction; whereas, the antibacterial activities were found in various cellular fractions and were capable of inhibiting common undesirable microorganisms in foods. In total, two lipases, seven proteases, and three antibacterial proteins were identified by LC-MS/MS. Characterization of LAB strains with high enzymatic activity has potential biotechnological significance in fermentative processes and in human health as they may improve the physicochemical characteristics of foods and displace strains with weaker enzymatic activities in the human gut microbiota.