Enhancement of γ-aminobutyric acid (GABA) production by Lactobacillus brevis CRL 2013 based on carbohydrate fermentation

CATALDO, PABLO G.; VILLEGAS, JOSEFINA M.; SAVOY DE GIORI, GRACIELA; SAAVEDRA, LUCILA; HEBERT, ELVIRA M.

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

ELSEVIER SCIENCE BV

Año: 2020 vol. 333

0168-1605

Gamma aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in nature and itsphysiological importance goes beyond its role as an inhibitory neurotransmitter of the central nervous system inmammals. Since microbial fermentation is one of the most promising methods to obtain GABA, the production ofthis metabolite by several strains of lactic acid bacteria isolated from quinoa and amaranth sourdoughs wasinvestigated. Lactobacillus brevis CRL 2013 produced the highest GABA levels, reaching 265 mM when optimalculture conditions were set up. The fermentative profile showed that CRL 2013 was able to catabolize carbohydratesthrough the phosphoketolase pathway yielding variable amounts of lactic acid, acetate and ethanol,which depended on the type of carbon source available and the presence of external electron acceptors such asfructose. Enhanced growth parameters and low GABA synthesis were associated to pentose fermentation. Thisimpairment on GABA production machinery was partially overpassed by the addition of ethanol to the culturemedia. These results support the potential use of L. brevis CRL 2013 as a starter culture for the manufacture ofGABA-enriched functional foods and provide further insights to the understanding of the GAD system regulationin lactic acid bacteria.