GABA synthesizing lactic acid bacteria and genomic analysis of Levilactobacillus brevis LAB6

• Published in: 3 Biotech 2024-03, Vol.14 (3), p.62-62, Article 62
• Main Authors: Matta, Tushar, Bhatia, Ruchika, Joshi, Santa Ram, Bishnoi, Mahendra, Chopra, Kanwaljit, Kondepudi, Kanthi Kiran
• Format: Article
• Language: English
• Subjects: adhesion; Agriculture; anti-inflammatory activity; Anti-inflammatory agents; Bacteria; Bifidobacterium; bile resistance; Bioinformatics; Biomaterials; Biotechnology; Cancer Research; Chemistry; Chemistry and Materials Science; coculture; Gene sequencing; Genes; Genomic analysis; genomics; Glutamate decarboxylase; Inflammation; Lactic acid; Lactic acid bacteria; Lactobacillus; Levilactobacillus brevis; metabolism; Monosodium glutamate; Original Article; Probiotics; Sodium glutamate; Stem Cells; Strains (organisms); Whole genome sequencing; γ-Aminobutyric acid
• ISSN: 2190-572X; 2190-5738
• DOI: 10.1007/s13205-024-03918-7

This study was conducted to investigate the γ-aminobutyric acid (GABA) production ability of 20 Lactobacillus and 25 Bifidobacterium strains which were previously isolated in our laboratory. Effect of initial pH, incubation time, monosodium glutamate (MSG), and pyridoxal-5′-phosphate (PLP) concentration for highest GABA production by two potent bacterial strains, Levilactobacillus brevis LAB6 and Limosilactobacillus fermentum LAB19 were optimized in the MRS media. A threefold increase in GABA production at an initial pH 4.0, incubation time of 120 h in medium supplemented with 3% MSG and 400 μM of PLP for LAB6 and 300 μM for LAB19 lead to the production of 19.67 ± 0.28 and 20.77 ± 0.14 g/L of GABA, respectively. Coculturing both strains under optimized conditions led to a GABA yield of 20.02 ± 0.17 g/L. Owing to potent anti-inflammatory activity in-vitro , as reported previously, and highest GABA production ability of LAB6 (MTCC 25662), its whole-genome sequencing and bioinformatics analysis was carried out for mining genes related to GABA metabolism. LAB6 harbored a complete glutamate decarboxylase ( GAD ) gene system comprising gadA , gadB , and gadC as well as genes responsible for the beneficial probiotic traits, such as for acid and bile tolerance and host adhesion. Comparative genomic analysis of LAB6 with 28 completely sequenced Levilactobacillus brevis strains revealed the presence of 95 strain-specific genes-families that was significantly higher than most other L. brevis strains.