Characterisation of the probiotic potential of Lactiplantibacillus plantarum K16 and its ability to produce the postbiotic metabolite γ-aminobutyric acid

Lactiplantibacillus plantarum has been widely studied due to its beneficial effects on health such as protect against pathogens, enhance the immune system, or produce metabolites like γ-aminobutyric acid (GABA). The objective of this study was the evaluation of the GABA-producer L. plantarum K16 isolated from kimchi. The safety and probiotic characterisation of this strain was performed by analysing carbohydrates fermentation, enzymatic activity, antibiotics susceptibility, and haemolytic and antimicrobial activity. Likewise, GABA production was optimised following a one-factor-at-a-time procedure by changing relevant fermentation parameters like incubation temperature, yeast extract concentration and fermentation time. The results indicated that L. plantarum K16 has the potential to stimulate the digestion and absorption of several nutrients and it could have an inhibitory effect against pathogenic bacteria. The best results for GABA production by this strain was around 1000 mg/L, using 12 g/L of yeast extract, 34 °C of incubation temperature and 96 h of fermentation time.