Marina Georgalaki, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Georgia Zoumpopoulou, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Eleni Mavrogonatou, Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research “Demokritos”, Athens, Greece
Gonzalez Van Driessche, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
Rania Anastasiou, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Voula Alexandraki, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Maria Kazou, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Marina Papadelli, Department of Food Technology, Technological Educational Institute of Peloponnese, Antikalamos, 24 100, Kalamata, Greece
Eugenia Manolopoulou, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Konstantinos Papadimitriou, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Dimitris Kletsas, Laboratory of Cell Proliferation and Ageing, Institute of Biosciences and Applications, National Centre for Scientific Research “Demokritos”, 153 10, Athens, Greece
Bart Devreese, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
Effie Tsakalidou, Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
Introduction: Fermented dairy products containing lactic acid bacteria (LAB) with bio-functional features are considered to be beneficial for human health. Probiotic potential and production of bioactive peptides are considered among the most promising features of LAB to be exploited as starter cultures in the industrial production of functional foods.
Purpose: In the present study, 106 LAB strains isolated from traditional Greek products have been studied regarding their probiotic potential as well as their ability to produce, when grown in cow, sheep and goat milk, bioactive peptides with inhibitory activity against the angiotensin-converting enzyme (ACE-I).
Methods: Strain typing and identification at the species level were performed by rep-PCR and 16S rDNA sequencing, respectively. The ACE-I activity was evaluated using a spectrophotometric assay. Semi-preparative HPLC, MS and MS/MS analyses were performed for ACE-I peptide purification and identification. Adhesion was studied using collagen-coated microtiter plates and the human enteric cell line HT-29. Immunomodulatory properties were evaluated by an in vitro co-culture model with human THP1 cells, while expression of COX2, iNOS, IL-10 and IL-12 genes was estimated by qPCR.
Results: Among the 106 tested LAB strains, 77 exhibited ACE-I activity while MS/MS analysis revealed the production of ACE-I and immunomodulatory peptides deriving from αs1-, β- and κ-caseins. Ten and two strains were able to adhere to collagen plates or HT-29 cells, respectively. COX2 and iNOS were equivalently expressed at low levels, while three strains exhibited high ratios of IL-10/IL-12, an indicator of anti-inflammatory potential.
Significance: These results indicate the potential use of the strains under investigation in novel probiotic dairy products.
