Deteksi Gamma-Aminobutyric Acid (GABA) pada bakteri asam laktat hasil isolasi produk fermentasi petis ikan dari Rembang

Abstract

Fish paste is a traditional fermented product made from fish broth that is cooked until thick. Paste is included in the type of cooking spices and food ingredients in the form of pasta, elastic and brown or black. Fish paste is included in traditional fermented foods. Food fermentation process is closely related to the presence of Lactic Acid Bacteria (LAB). Lactic Acid Bacteria (LAB) is known to produce antioxidant compounds namely Gamma-Aminobutyric Acid (GABA). Gamma-Aminobutyric Acid (GABA) is a non-protein amino acid which is produced by decarboxylation of glutamate by the enzyme glutamate decarboxylase and is widely distributed in nature among microorganisms, plants, and animals. The purpose of this study was to obtain LAB isolates that produce GABA. Isolation was carried out by the streak method of fish paste samples which had been stratified diluted and planted on MRSA + 1% CaCO₃ media, incubated at 37°C for 48 hours. The pure isolates obtained were macroscopic and microscopic characterization of colonies and cells. LAB growth on MRSB media was carried out for 60 hours at 37°C, then identified the production of GABA qualitatively by Thin Layer Chromatography (TLC) using aluminum TLC plates (Silica gel F254, Merck, Mumbai India). Developer solution (eluent) consisting of a mixture of n-butanol: acetic acid: distilled water in a ratio of 5: 3: 2. The results of isolation obtained 2 isolates of Lactic Acid Bacteria which were coded PTS-A2 and PTA-A3. Both LAB isolates that produce GABA compounds can be seen from the value of Retention factor (Rf) in TLC, namely Rf PTS-A2 and PTS-A3 isolates = 0.65, Rf MSG = 0.45 while the GABA (Pregabalin) standard is 0.65.