Production of gaba (γ - aminobutyric acid) by microorganisms: a review

Abstract

GABA (γ-aminobutyric acid) is a four carbon non-protein amino acid that is widely distributed in plants, animals and microorganisms. As a metabolic product of plants and microorganisms produced by the decarboxylation of glutamic acid, GABA functions as an inhibitory neurotransmitter in the brain that directly affects the personality and the stress management. A wide range of traditional foods produced by microbial fermentation contain GABA, in which GABA is safe and eco-friendly, and also has the possibility of providing new health-benefited products enriched with GABA. Synthesis of GABA is catalyzed by glutamate decarboxylase, therefore, the optimal fermentation condition is mainly based on the biochemical properties of the enzyme. Major GABA producing microorganisms are lactic acid bacteria (LAB), which make food spoilage pathogens unable to grow and act as probiotics in the gastrointestinal tract. The major factors affecting the production of GABA by microbial fermentation are temperature, pH, fermentation time and different media additives, therefore, these factors are summarized to provide the most up-dated information for effective GABA synthesis. There has been a huge accumulation of knowledge on GABA application for human health accompanying with a demand on natural GABA supply. Only the GABA production by microorganisms can fulfill the demand with GABA-enriched health beneficial foods.

Irritable bowel syndrome, the microbiota and the gut-brain axis

“…The clinical implications herof still need to be explored. 145,146 New modulators of GABA B may provide a novel therapeutis for treatment of visceral pain disorders, 147 Endogenous systems, which also may become new targets in the IBS therapy, include cortico-releasing-factor receptor, neurokinin receptors cannabinoid, and opioid receptors and their ligands.…”

Screening and optimization of γ-aminobutyric acid production fromMonascus sanguineusunder solid-state fermentation

“…They involve the bioconversion of decarboxylating glutamate to GABA, catalysed by the enzyme glutamate decarboxylase (GAD). Various techniques such as immobilized cell technology, sourdough fermentation and batch fermentation methods have been used for GABA production from microbial sources, and fermentation factors such as pH, temperature, cultivation time and media additives in the culture are considered to be of key importance for optimizing the GABA yield (Dhakal et al 2012). …”

Optimized Production of GABA and γ-PGA in a Turmeric and Roasted Soybean Mixture Co-fermented by <i>Bacillus subtilis</i> and <i>Lactobacillus plantarum</i>

“…Therefore, improving the organoleptic qualities of fermented soy products is desirable. A co-fermentation with B. subtilis MC31 andLactobacillus sakei 83 was reported to enhance the GABA contentand flavor of chungkookjang .The lactic acid bacteria (LAB) used to make fermented food products generate functional compounds such as oligosaccharides and peptides in addition to lactic acid (Leroy and De Vuyst, 2004).One of the functional compounds that can be generated by fermentation with LAB is γ-aminobutyric acid (GABA), a nonprotein amino acid that acts as an inhibitory neurotransmitter and that also exhibits hypotensive effects (Dhakal et al, 2012). In LAB, GABA acts as a defense against acidic environments and as an alternative energy source (Kook et al, 2010a).…”

“…One of the functional compounds that can be generated by fermentation with LAB is γ-aminobutyric acid (GABA), a nonprotein amino acid that acts as an inhibitory neurotransmitter and that also exhibits hypotensive effects (Dhakal et al, 2012). In LAB, GABA acts as a defense against acidic environments and as an alternative energy source (Kook et al, 2010a).…”