Production of gamma-aminobutyric acid by Lactobacillus brevis NCL912 using fed-batch fermentation

<p>Abstract</p> <p>Background</p> <p>Gamma-aminobutyric acid is a major inhibitory neurotransmitter in mammalian brains, and has several well-known physiological functions. Lactic acid bacteria possess special physiological activities and are generally regarded as safe. Therefore, using lactic acid bacteria as cell factories for gamma-aminobutyric acid production is a fascinating project and opens up a vast range of prospects for making use of GABA and LAB. We previously screened a high GABA-producer <it>Lactobacillus brevis </it>NCL912 and optimized its fermentation medium composition. The results indicated that the strain showed potential in large-scale fermentation for the production of gamma-aminobutyric acid. To increase the yielding of GABA, further study on the fermentation process is needed before the industrial application in the future. In this article we investigated the impacts of pyridoxal-5'-phosphate, pH, temperature and initial glutamate concentration on gamma-aminobutyric acid production by <it>Lactobacillus brevis </it>NCL912 in flask cultures. According to the data obtained in the above, a simple and effective fed-batch fermentation method was developed to highly efficiently convert glutamate to gamma-aminobutyric acid.</p> <p>Results</p> <p>Pyridoxal-5'-phosphate did not affect the cell growth and gamma-aminobutyric acid production of <it>Lb. brevis </it>NCL912. Temperature, pH and initial glutamate concentration had significant effects on the cell growth and gamma-aminobutyric acid production of <it>Lb. brevis </it>NCL912. The optimal temperature, pH and initial glutamate concentration were 30-35°C, 5.0 and 250-500 mM. In the following fed-batch fermentations, temperature, pH and initial glutamate concentration were fixed as 32°C, 5.0 and 400 mM. 280.70 g (1.5 mol) and 224.56 g (1.2 mol) glutamate were supplemented into the bioreactor at 12 h and 24 h, respectively. Under the selected fermentation conditions, gamma-aminobutyric acid was rapidly produced at the first 36 h and almost not produced after then. The gamma-aminobutyric acid concentration reached 1005.81 ± 47.88 mM, and the residual glucose and glutamate were 15.28 ± 0.51 g L^-1and 134.45 ± 24.22 mM at 48 h.</p> <p>Conclusions</p> <p>A simple and effective fed-batch fermentation method was developed for <it>Lb. brevis </it>NCL912 to produce gamma-aminobutyric acid. The results reveal that <it>Lb. brevis </it>NCL912 exhibits a great application potential in large-scale fermentation for the production of gamma-aminobutyric acid.</p

Optimization of Gamma-Aminobutyric Acid Production in Probiotics Extracted from Local Dairy Products in West Region of Iran using MRS broth and Whey Protein Media

Background and objective: Gamma-aminobutyric acid is a non-protein amino acid produced by lactic acid bacteria in fermented foods and includes unique functions in the human biological system. The aim of this study was optimization of culture media for gamma-aminobutyric acid production in probiotics extracted from local dairy products in west of Iran using two culture media of MRS broth and whey protein.Material and methods: The potential of gamma-aminobutyric acid production was assessed in Lactobacillus paracasei, Lactobacillus plantarum and Pediococos acidilactici, respectively extracted from doogh, yogurt and cheese using MRS broth and whey protein media and high performance liquid chromatography. To increase gamma-aminobutyric acid production, these media were optimized as pH (4-6), temperature (30-50°C), time (12-72 h) and glutamic acid concentration (25-250 mM).Results and conclusion: Results have shown that Lactobacillus plantarum extracted from doogh includes the highest potential of gamma-aminobutyric acid production (115.24 mg kg-1) under the following conditions of a culture temperature of 37°C, incubation time 60 h at pH 5 in MRS broth containing 50 mM of glutamic acid. After optimization of Lactobacillus plantarum media, gamma-aminobutyric acid production increased to 170.492 mg kg-1. The optimum conditions included a glutamic acid concentration of 250 mM, culture temperature at 37.27°C, pH=5.19 and an incubation time of 72 h. Based on the results, use of local isolated dairy products in west region of Iran and optimization of growth conditions increased the ability of gamma-aminobutyric acid production.Conflict of interest: The authors declare no conflict of interest

GABA and Dopamine Release from Different Brain Regions in Mice with Chronic Exposure to Organophosphate Methamidophos

Organophosphates such as methamidophos, usually used in the agricultural field, have harmful effects on humans. Exposures to insecticides has been associated with many disorders, including damage to the central and peripheral nervous system. Chronic exposure to organophosphates may lead to persistent neurological and neurobehavioral effects. This study was conducted to determine the effect of methamidophos on [3H]-dopamine (DA) and gamma aminobutyric acid (GABA) release from different brain regions after chronic exposure to it for 3, 6 or 9 months. After a six-month methamidophos treatment, the mice showed high susceptibility to convulsive seizures and a reduction in stimulated gamma aminobutyric acid release from the cerebral cortex and hippocampal slices, whereas stimulated (DA) release was slightly decreased from the striatum after three months of methamidophos exposure. The results indicate changes in gamma aminobutyric acid and dopamine neurotransmission, suggesting a specific neuronal damage

Current Perspective on the Location and Function of Gamma- Aminobutyric Acid (GABA) and its Metabolic Partners in the Kidney.

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter located in the mammalian central nervous system, which binds to GABAA and GABAB receptors to mediate its neurological effects. In addition to its role in the CNS, an increasing number of publications have suggested that GABA might also play a role in the regulation of renal function. All three enzymes associated with GABA metabolism; glutamic acid decarboxylase, GABA ?-oxoglutarate transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH) have been localised to the kidney providing the necessary machinery for localised GABA synthesis and metabolism. Moreover GABA receptors have been localised to both tubular and vascular structures in the kidney, and GABA is excreted in urine (~3 ?M) in humans. Despite the collective evidence describing the presence of a GABA system in the kidney, the precise function of such a system requires further clarification. Here we provide an overview of the current renal GABA literature and provide novel data that indicates GABA can act at contractile pericyte cells located along vasa recta capillaries in the renal medulla to potentially regulate medullary blood flow

A systematic review of Gamma-aminobutyric Acid Receptor Type B autoimmunity

Objective. To review the available research to describe the clinical characteristics and neoplastic associations of patients with gamma-aminobutyric acid receptor type B (GABAB-R) autoantibodies. Methods. Literature was reviewed on PubMed, Mendeley literature search, and the American Academy of Neurology database for articles published from June 2008 to October of 2018 using a variety of key words. These key words include: „gamma-aminobutyric acid seizures,” „gamma-aminobutyric acid limbic encephalitis”, „GABA(B) receptor antibodies,” „autoimmune encephalitis,” „autoimmune epilepsy,” „GABA(B) encephalitis, „ and “GABA paraneoplastic.” With the results, the papers were reviewed in a systematic manner. Results. A total of 10 studies were reviewed. A summary of the demographic, clinical, and serological findings of the cases detailed in the literature are provided. An additional illustrative case is described. In total, 94 patients were reviewed. Conclusions. GABAB-R autoimmune disease is characterized by refractory seizures or status epilepticus and frequent association with small cell lung cancer. Additionally, a substantial minority of patients have non-inflammatory CSF.

Evidence for a GABAergic system in rodent and human testis: Local GABA production and GABA receptors

The major neurotransmitter of the central nervous system, gamma-aminobutyric acid (GABA), exerts its actions through GABA(A), GABA(B) and GABA(C) receptors. GABA and GABA receptors are, however, also present in several non-neural tissues, including the endocrine organs pituitary, pancreas and testis. In the case of the rat testis, GABA appears to be linked to the regulation of steroid synthesis by Leydig cells via GABA(A) receptors, but neither testicular sources of GABA, nor the precise nature of testicular GABA receptors are fully known. We examined these points in rat, mouse, hamster and human testicular samples. RT-PCR followed by sequencing showed that the GABA-synthesizing enzymes glutamate decarboxylase (GAD) 65 and/or GAD67, as well as the vesicular GABA transporter vesicular inhibitory amino acid transporter (VIAAT/VGAT) are expressed. Testicular GAD in the rat was shown to be functionally active by using a GAD assay, and Western blot analysis confirmed the presence of GAD65 and GAD67. Interstitial cells, most of which are Leydig cells according to their location and morphological characteristics, showed positive immunoreaction for GAD and VIAAT/VGAT proteins. In addition, several GABA(A) receptor subunits (alpha1-3, beta1-3, gamma1-3), as well as GABAB receptor subunits R1 and R2, were detected by RT-PCR. Western blot analysis confirmed the results for GABA(A) receptor subunits beta2/3 in the rat, and immunohistochemistry identified interstitial Leydig cells to possess immunoreactive GABA(A) receptor subunits beta2/3 and alpha1. The presence of GABA(A) receptor subunit alpha1 mRNA in interstitial cells of the rat testis was further shown after laser microdissection followed by RT-PCR analysis. In summary, these results describe molecular details of the components of an intratesticular GABAergic system expressed in the endocrine compartment of rodent and human testes. While the physiological significance of this peripheral neuroendocrine system conserved throughout species remains to be elucidated, its mere presence in humans suggests the possibility that clinically used drugs might be able to interfere with testicular function. Copyright (C) 2003 S. Karger AG, Basel

Changes of Neurotransmitters in Youth with Internet and Smartphone Addiction: A Comparison with Healthy Controls and Changes after Cognitive Behavioral Therapy

BACKGROUND AND PURPOSE: Neurotransmitter changes in youth addicted to the Internet and smartphone were compared with normal controls and in subjects after cognitive behavioral therapy. In addition, the correlations between neurotransmitters and affective factors were investigated. MATERIALS AND METHODS: Nineteen young people with Internet and smartphone addiction and 19 sex- and age-matched healthy controls (male/female ratio, 9:10; mean age, 15.47 +/- 3.06years) were included. Twelve teenagers with Internet and smartphone addiction (male/female ratio, 8:4; mean age, 14.99 +/- 1.95years) participated in 9 weeks of cognitive behavioral therapy. Meshcher-Garwood point-resolved spectroscopy was used to measure gamma-aminobutyric acid and Glx levels in the anterior cingulate cortex. The gamma-aminobutyric acid and Glx levels in the addicted group were compared with those in controls and after cognitive behavioral therapy. The gamma-aminobutyric acid and Glx levels correlated with clinical scales of Internet and smartphone addiction, impulsiveness, depression, anxiety, insomnia, and sleep quality. RESULTS: Brain parenchymal and gray matter volume-adjusted gamma-aminobutyric acid-to-creatine ratios were higher in subjects with Internet and smartphone addiction (P = .028 and .016). After therapy, brain parenchymal- and gray matter volume-adjusted gamma-aminobutyric acid-to-creatine ratios were decreased (P = .034 and .026). The Glx level was not statistically significant in subjects with Internet and smartphone addiction compared with controls and posttherapy status. Brain parenchymal- and gray matter volume-adjusted gamma-aminobutyric acid-to-creatine ratios correlated with clinical scales of Internet and smartphone addictions, depression, and anxiety. Glx/Cr was negatively correlated with insomnia and sleep quality scales. CONCLUSIONS: The high gamma-aminobutyric acid levels and disrupted balance of gamma-aminobutyric acid-to-Glx including glutamate in the anterior cingulate cortex may contribute to understanding the pathophysiology and treatment of Internet and smartphone addiction and associated comorbidities.ope

Sedative-like effect of intraperitoneal GABA administration in the open field test

Gamma-Amino Butyric Acid (GABA) is the main inhibitor neurotransmitter of the Central Nervous System (CNS). Its peripheral administration has been matter of discussion. On the one hand, it has been reported that it does not cross the Blood-Brain Barrier (BBB), and, on the other hand, it has been associated with multiple therapeutic regimens and supplements by peripheral administration. The aim of the present study is to elucidate the possibility of a central sedative effect when administered peripherally. An experimental cohort of 90-day-old Holtzman male rats weighing 240-270 g was used. It was divided into 2 groups: saline-controls (n = 9) and GABA treated rats (12.5 mg/kg, n = 9). Both groups were intraperitoneally injected. The motor behavioral patterns displayed in the Opto Varimex (OVM) were studied. Vertical, horizontal, ambulatory and non-ambulatory movements and the number of movements were recorded in an automated way. Horizontal movements constitute the integration of ambulatory and non-ambulatory movements. Student t test was used comparing groups. In this experiment, there were non-significant downward trends in vertical, ambulatory, non-ambulatory and number of movements. Ambulatory and non-ambulatory tendencies acquired significance when treated together as horizontal movements (p < 0.05). We may conclude that peripheral administration of GABA produced a decrease of the horizontal movements in the open field test. It may be interpreted as a sedative effect, suggesting a passage of GABA through BBB, with central effects. However, there are several alternative possibilities to explain present findings. Other experiments will elucidate the implications or scope of the present findings.Fil: Gargiulo, Augusto Pascual Ítalo. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; ArgentinaFil: Marquez Herrero, Santiago. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; ArgentinaFil: Romanowicz, Esteban Alejandro. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; ArgentinaFil: Guevara, Manuel Alejandro. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; ArgentinaFil: Landa, Adriana Inés. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; ArgentinaFil: Lafuente, José Vicente. Universidad del País Vasco; EspañaFil: Mesones, Humberto Luis. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Fundación Instituto de Neurobiología; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; ArgentinaFil: Gargiulo, Pascual Angel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Laboratorio de Neurociencias y Psicología Experimental; Argentina. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas; Argentin