Characterization of Gamma Aminobutyric Acid-producing Lactic Acid Bacteria Isolated from Budu Fish in Padang Pariaman West Sumatra Indonesia and their Potentials as Probiotics

Abstract

Abstract Background and Objective: Screening of lactic acid bacteria for the production of gamma-amino-butyric acid is important due to its pharmacological functions. In this study, isolation and characterization of lactic acid bacteria from Budu fish, an endemic fish to West Sumatra, Indonesia, have been investigated and their gamma amino butyric acid-producing potentials were identified Material and Methods: The research method was as follows: lactic acid bacteria was isolated from Budu fish bought randomly from a traditional market in West Sumatra, Indonesia. Isolates were characterized morphologically and biochemically. Gram+ isolates were investigated for their capability to produce gamma-amino-butyric acid using thin-layer chromatography. Gamma-amino-butyric acid-positive strains were quantitatively analyzed using spectrometry method. Of the five samples, the highest gamma-amino-butyric acid production was reported in one sample of IB2C isolate. The selected isolates of lactic acid bacteria were molecularly identified using 16S rRNA gene sequencing. Effects of incubation time (20, 40 and 60 h) and monosodium glutamate concentrations (2, 4 and 6%) were investigated on gamma-amino-butyric acid-production strains. Results and Conclusion: Three isolates were selected for the production of gamma-amino-butyric acid in de Mann Rogosa Sharpe broth containing 1% monosodium glutamate. Semiquantitative analysis via pre-staining paper chromatography was carried out to identify the highest gamma amino butyric acid-producing lactic acid bacteria. The highest gamma-amino-butyric acid level of 22.5 mg.ml-1 was achieved using 60 h of incubation and 6% of monosodium glutamate concentration in de Mann Rogosa Sharpe broth. The IB2c isolates were Gram+, catalase-, homofermentative and able to utilize various carbon sources. It inhibited growth of Escherichia coli O157, Staphylococcus aureus and Salmonella enteritidis. The IB2C was further characterized molecularly using 16S rRNA sequencing gene. Results were identified as Lentilactobacillus parabuchneri strain M1-40. A 97.69% similarity of lactic acid bacteria isolated from Budu fish with Lentilactobacillus. parabuchneri indicates probiotic use of the gamma-amino butyric acid-producing lactic acid bacteria