Enzymatic Production of γ-Aminobutyric Acid Using Rice Bran

2012 ◽  
Vol 586 ◽  
pp. 85-91
Author(s):  
Ying Guo Lü ◽  
Hui Zhang ◽  
Hui Yuan Yao

An enzymatic method for γ-aminobutyric acid (GABA) production was invested. With this method, rice bran was used as glutamate decarboxylase (GAD) source and exogenous monosodium glutamate(MSG) was used as substrate. We stimulated the rice bran GAD via regulating the temperature, pH, reaction time, buffer and adding PLP, Ca2+ and substrate. In the existence of PLP and Ca2+, the GABA content of rice bran had been improved by about 45 fold. The GABA production reached 2.3g/100g bran, and the Glu conversion reached 100%. As rice bran is a by-product in rice processing and a large quantity of rice bran is commercially available, our study illuminated a safe and efficient way to produce GABA and GABA enriched food.

2021 ◽  
Vol 63 (1) ◽  
pp. 42-48
Author(s):  
Dai Hung Ngo ◽  
◽  
Quoc Tuan Tran ◽  
Thi Nhat Hang Nguyen ◽  
Dai Nghiep Ngo ◽  
...  

Gamma-aminobutyric acid (GABA) is a potent bioactive component that widely exists in both plants and animals, has numerous health benefits. This study aimed to optimise the fermentation process conditions for the growth of Lactobacillus fermentum from rice bran extracts that have high potential to produce GABA. GABA content was assessed by thin-layer chromatography (TLC) method. In this study, fermenting conditions for medium production of GABA by L. fermentum from rice bran extracts were optimised. L. fermentum showed high potential for GABA-producing ability. Some factors influencing the GABA production such as carbon sources, nitrogen sources, mineral salt sources, substrate concentration of monosodium glutamate (MSG), pH, and the time of fermentation were investigated. When the L. fermentum is cultivated in the rice bran extracts medium supplemented with 1.5% lactose, 2% yeast extract, and 1% MSG with pH 6.0 in 48 h, this strain showed high GABA at a concentration of 736 mg/l.


Author(s):  
Cat Thien Phuc ◽  
Doan Thi Thanh Vinh ◽  
Truong Khoa My ◽  
Tran Thi Thu Hien ◽  
Nguyen Anh Dung ◽  
...  

Lactic acid bacteria play a vital role in biosynthesis of γ -aminobutyric acid (GABA) in the presence of glutamic acid - major substrate for the process. In recent study, Lactobacillus fermentum A01 (L. fermentum A01) isolated from various sources in Vietnam were screened for bacteria strains with high efficiency in GABA formation. L. fermentum was cultured in MRS broth containing 25 mg/mL monosodium glutamate (MSG), at pH of 6.5 and incubated at the optimal conditions (37ºC, for 24, 48, 72 h). After extraction and thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analysis, L. fermentum A01 showed the GABA yield about 1.34 mg/g in dried supernatant, suggesting L. fermentum A01 to be a promising GABA producer for food and pharmaceutical applications.


Foods ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 218 ◽  
Author(s):  
Manuel Venturi ◽  
Viola Galli ◽  
Niccolò Pini ◽  
Simona Guerrini ◽  
Lisa Granchi

γ-Aminobutyric acid (GABA) is the primary inhibitory neurotransmitter of the central nervous system and possesses various physiological functions. GABA production can be obtained thanks to lactic acid bacteria activity in different foods such as sourdoughs. Recently, breads made from blends of pseudocereals and wheat flours have attracted much attention. Amaranth is especially interesting because of its high nutritional value, having a high protein content and containing different antioxidant compounds. Therefore, this study aimed to obtain sourdough breads enriched with GABA thanks to bacterial activity and to investigate the effect of amaranth flour addition on the antioxidant and sensorial properties of bread. Eighteen lactobacilli strains were assayed for GABA production in amaranth and wheat flour liquid sourdoughs. Two strains, Lactobacillus brevis A7 and Lactobacillus farciminis A11, demonstrated high GABA producing capability; hence, they were used to prepare breads containing 20% amaranth flour. The results confirmed the capability of the two strains to increase GABA concentrations (up to 39 mg/kg) in breads. Samples with amaranth addition showed a significantly higher total phenolic content compared to the control bread (more than 15 mg GAE 100 g−1 dwb); sensory analysis showed that breads with amaranth were moderately acceptable. Nevertheless, their general liking evaluation was significantly lower compared to the control bread. The addition of pseudocereal to traditional wheat sourdough and selection of lactobacilli allowed the production of baked goods with enhanced GABA content and antioxidant capacity, but recipes have to be developed to increase the organoleptic acceptability of the final products.


2021 ◽  
Author(s):  
Li-Li Yao ◽  
Jia-Ren Cao ◽  
Chang-Jiang Lyu ◽  
Fang-Fang Fan ◽  
Hong-Peng Wang ◽  
...  

Abstract Objectives γ-Aminobutyric acid (GABA) is a non-protein amino acid, considered a potent bioactive compound. This study focused on biosynthesis of food-grade GABA by immobilized glutamate decarboxylase (GAD) from Lactobacillus plantarum in the rice vinegar and monosodium glutamate (MSG) reaction system.Results The gene encoding GadB from L. plantarum has been heterologously expressed in Lactococcus lactis and biochemically characterized. Recombinant GadB existed as a homodimer, and displayed maximal activity at 40℃ and pH 5.0. The Km value and catalytic efficiency (kcat/Km) of GadB for L-Glu was 22.33 mM and 1.04 L/(mmol·s), respectively, with a specific activity of 24.97 U/mg protein. Then, purified GadB was encapsulated in gellan gum beads. Compared to the free enzyme, immobilized GadB showed higher operational and storage stability. Finally, 9.82 to 21.48 g/L of GABA have been acquired by regulating the amounts of catalyst microspheres ranging from 0.5 to 0.8 g (wet weight) in 0.8 mL of the designed rice vinegar and MSG reaction system. Conclusions The method of production GABA by immobilized GadB microspheres mixed in the rice vinegar and MSG reaction system is introduced herein for the first time. Especially, the results obtained here meet the increased interest in the harnessing of biocatalyst to synthesize food-grade GABA.


2021 ◽  
Vol 9 (12) ◽  
pp. 2457
Author(s):  
Divakar Dahiya ◽  
Jemima V. Manuel ◽  
Poonam Singh Nigam

Gamma-aminobutyric acid (GABA) is an important chemical compound in the human brain. GABA acts as an inhibitory neurotransmitter by inducing hyperpolarization of cellular membranes. Usually, this pharmaceutically important compound is synthesized using a chemical process, but in this short overview we have only analysed microbial processes, which have been studied for the biosynthesis of this commercially important compound. The content of this article includes the following summarised information: the search for biological processes showed a number of lactic acid bacteria and certain species of fungi, which could be effectively used for the production of GABA. Strains found to possess GABA-producing pathways include Lactobacillus brevis CRL 1942, L. plantarum FNCC 260, Streptococcus salivarius subsp. thermophilus Y2, Bifidobacterium strains, Monascus spp., and Rhizopus spp. Each of these strains required specific growth conditions. However, several factors were common among these strains, such as the use of two main supplements in their fermentation medium—monosodium glutamate and pyridoxal phosphate—and maintaining an acidic pH. Optimization studies of GABA production were comprised of altering the media constituents, modifying growth conditions, types of cultivation system, and genetic manipulation. Some strains increased the production of GABA under anaerobic conditions. Genetic manipulation focused on silencing some genes or overexpression of gadB and gadC. The conclusion, based on the review of information available in published research, is that the targeted manipulation of selected microorganisms, as well as the culture conditions for an optimised bioprocess, should be adopted for an increased production of GABA to meet its increasing demand for food and pharmaceutical applications.


2019 ◽  
Vol 10 (5) ◽  
pp. 579-587 ◽  
Author(s):  
J.A. Valenzuela ◽  
A.B. Flórez ◽  
L. Vázquez ◽  
O.M. Vasek ◽  
B. Mayo

γ-Aminobutyric acid (GABA), an amino acid not used in protein synthesis, intervenes in several physiological functions and has both diuretic and calming effects in humans. Lactic acid bacteria (LAB) strains that produce GABA could be exploited for the manufacture of health-promoting GABA-enriched dairy products. In this study, 262 LAB strains isolated from traditional dairy products made from raw milk without starter cultures were screened for GABA production in culture media supplemented with 1% monosodium glutamate (MSG) using an enzymatic (GABase) method. About half of the strains (123) were found to be GABA producers. Of these, 24, among which were 16 Lactococcus lactis subsp. lactis and three Streptococcus thermophilus strains, produced >1 mM of GABA (range 1.01-2.81 mM) and were selected for further characterisation. GABA production was confirmed in most strains by culturing in 5 mM MSG followed by HPLC quantification. A majority of the strains were confirmed to be GABA producers by this method, although lower production levels were recorded. Using species-specific primers, the gene encoding glutamate decarboxylase (GAD) was PCR-amplified in all but one of the GABA producers analysed. Amplicons sequences were compared to one another and to those held in databases. Except for one Lactobacillus brevis strain, none of the 24 GABA producers investigated produced toxic biogenic amines, such as tyramine, histamine or cadaverine. They were therefore considered safe. Either alone, in mixtures, or in combination with industrial starter or adjunct cultures, these strains might be useful in the development of health-oriented dairy products.


Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 22
Author(s):  
Ida Bagus Agung Yogeswara ◽  
Suwapat Kittibunchakul ◽  
Endang Sutriswati Rahayu ◽  
Konrad J. Domig ◽  
Dietmar Haltrich ◽  
...  

In the present study, we isolated and screened thirty strains of GABA (γ-aminobutyric acid)-producing lactic acid bacteria (LAB) from traditional Indonesian fermented foods. Two strains were able to convert monosodium glutamate (MSG) to GABA after 24 h of cultivation at 37 °C based on thin layer chromatography (TLC) screening. Proteomic identification and 16S rDNA sequencing using MALDI-TOF MS identified the strain as Lactobacillus plantarum designated as L. plantarum FNCC 260 and FNCC 343. The highest yield of GABA production obtained from the fermentation of L. plantarum FNCC 260 was 809.2 mg/L of culture medium after 60 h of cultivation. The supplementation of 0.6 mM pyridoxal 5’-phosphate (PLP) and 0.1 mM pyridoxine led to the increase in GABA production to 945.3 mg/L and 969.5 mg/L, respectively. The highest GABA production of 1226.5 mg/L of the culture medium was obtained with 100 mM initial concentration of MSG added in the cultivation medium. The open reading frame (ORF) of 1410 bp of the gadB gene from L. plantarum FNCC 260 encodes 469 amino acids with a calculated molecular mass of 53.57 kDa. The production of GABA via enzymatic conversion of monosodium glutamate (MSG) using purified recombinant glutamate decarboxylase (GAD) from L. plantarum FNCC 260 expressed in Escherichia coli was found to be more efficient (5-fold higher within 6 h) than the production obtained from fermentation. L. plantarum FNCC 260 could be of interest for the synthesis of GABA.


Author(s):  
Bhargavi Rayavarapu ◽  
Padmavathi Tallapragada ◽  
Usha MS

Abstract Background ℽ-Aminobutyric acid (GABA) is a non-proteinaceous amino acid. In the mammalian nervous system, GABA functions as an inhibitory neurotransmitter. The present study focused on screening and optimization of ℽ-aminobutyric acid (GABA) yield by lactic acid bacteria by using soymilk as basal media. Lactobacillus fermentum (Lb. fermentum) was isolated from sourdough. The qualitative confirmation of GABA production by Lb. fermentum was observed by detecting colored spots on thin layer chromatography plate (TLC) and comparing it with standard GABA spot. The GABA from bacteria is confirmed by its molecular mass using mass spectrophotometry analysis (MS analysis). Single variable experiments were conducted for various physical and nutritional parameters, and determined the GABA content produced from Lb. fermentum, viable bacterial count, and pH of the fermented soymilk medium. Experimental data were authenticated by using response surface method (RSM) and artificial neural network (ANN) model. Results The results demonstrated that through single variable experiments, the yield of GABA and the viable bacterial cells increased in soymilk containing one percent of glucose, monosodium glutamate (MSG), and inoculum volume incubated at 37 °C, 48 h at pH 5. According to RSM results, the interaction of the highest concentration of MSG (1.5%) and mid glucose concentration (1.156%) yielded maximum GABA (5.54 g/L). The experimental data were in good agreement with two optimization models. The RSM models showed less error percentage than that of the ANN model. Conclusion This study indicates that soymilk is the best basal substrate for GABA production and growth of Lb. fermentum compared to synthetic media. Lb. fermentum can be explored further by food and pharmaceutical industries for the development of functional foods and therapeutic purposes.


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