The growth and potential of gamma-aminobutyric acid (GABA) by lactic acid bacteria isolated from fish fermented food from Maluku, Indonesia

Abstract

GABA is a non-protein amino acid that is widely distributed in plants, animals and microorganisms. GABA can increase plasma concentration, growth hormone and protein synthesis in the brain. Several studies have shown that LAB can reduce pathological conditions due to oxidative stress, which indicates that LAB has antioxidant activity. One of the metabolites produced by LAB is GABA. The purpose of this study was to determine the growth of LAB isolates, the ability of GABA production and to know the character of INS-A2 and INS A4 isolates as a result of isolation from fish fermented. Bacterial growth was carried out for 60 hours 37°C. The growth of LAB isolates INS-A2 and INS-A4 were treated with the addition of MSG and non-MSG 2% in MRSB. GABA production can be identified qualitatively by the Thin Layer Chromatography (TLC) method using the aluminum TLC plate (Silica gel F254, Merck, Mumbai India). The LAB inoculum which was treated on MRSB media was centrifuged at a speed of 6000 rpm for 20 minutes at 4°C, the supernatant was deposited or dropped on the TLC plate. TLC was carried out using an eluent consisting of a mixture of n-butanol: acetic acid: distilled water in a ratio of 5:3:2. The Rf value of GABA compound produced by LAB INS-A2 and INS A4 isolates was 0.62, GABA standard (Pregabalin) 0.62, Rf MSG = 0.23. Based on the results of the study it can be concluded that the highest growth of INS A2 MSG isolate at 24 hours, INS-A2 non MSG highest at 30 hours. The highest growth of INS A4 MSG isolate at 30 hours and INS-A4 non MSG highest at 36 hours. The highest GABA concentration was owned by INS-A2 MSG isolate of 20,0 mg/ml. INS-A2 non MSG isolate 17,5 mg/ml, INS-A4 MSG 18,8 mg/ml and INS-A4 non-MSG 15,9 mg/ml. LAB characterization of INS-A2 and INS-A4 isolates obtained negative catalase, negative motility, fermentation type test (homofermentative) and gram-positive staining in accordance with the characteristics of BAL in general.