Isolation and Characterization of Lactic Acid Bacteria Producing GABA from Indigenous West Sumatera Fermented Food

Abstract

The purpose of this study was to isolate and characterize lactic acid bacteria (LAB) from indigenous West Sumatera fermented foods. The aim was to obtain LAB isolates that have the ability to produce γ-aminobutyric acid (GABA) and to characterize the highest GABA producing LAB. The indigenous West Sumatera fermented foods sampled were dadih (fermented buffalo milk), asam durian (fermented durian), tape singkong (fermented cassava) and ikan budu (fermented fish). The conventional method was used to isolate LAB, after which LAB were screened for γ-amino butyric acid (GABA) and GABA producing LAB characterized by biochemical tests. A total of 704 isolates were successfully isolated. Five hundred fifty two (552) isolates were identified as LAB and 103 isolates were confirmed as GABA producing LAB. The highest GABA producing LAB was DS15 and produced 49.365 mg/ml of GABA. DS18 produced the least GABA of 3.415 mg/ml. Biochemical assay of DS15 showed that the isolate could grow on the MRSA, undergoes aerobic respiration, do not use lactose, glucose, mannitol, arginine, aesculin, arabinose, raffinose, sorbitol, trehalase and xylose/melezitose. The isolate DS15 was also negative for arginine, nitrate reduction, catalase and oxidase tests. Based on the gram stain reaction, the isolate DS15 was a gram-positive bacterium and could be classified as Lactobacillus sp.