Production of conjugated linoleic acid and gamma-aminobutyric acid by autochthonous lactic acid bacteria and detection of the genes involved

Abstract

In this study, 85 strains of lactic acid bacteria isolated from artisanal cheeses were screened to determine their capacity to synthesise bioactive compounds.Four Lactobacillus plantarum and two Lactobacillus casei subsp. casei strains were capable of synthesizing conjugated linoleic acid (CLA). The highest level of CLA formed in MRS after 48 h incubation was 19.26 µg/mL. Six Lactobacillus brevis and four Lactococcus lactis subp. lactis strains produced gamma-aminobutyric acid (GABA) and the highest concentration (2524.05 µg/mL) was found after 72 h incubation.The detection of genes encoding linoleate isomerase or glutamate decarboxylase system could be suitable for use as screening method of CLA or GABA-producer strains, although this should be studied in a larger number of strains.Our findings suggest that the above strains are potential candidates for the design of starter cultures with the capacity to generate bioactive compounds, offering new possibilities for the manufacture of functional dairy products.

Keywords

• CLA
• Dairy functional food
• GABA
• Glutamate decarboxylase
• Lactic acid bacteria
• Linoleate isomerase