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EFFECT OF FOOD-MICROORGANISMS ON GAMMA-AMINOBUTYRIC ACID PRODUCTION BY FERMENTATION  [PDF]
Robert Mazur,Jozef Hudec,Kamila Kovalovská
Journal of Microbiology, Biotechnology and Food Sciences , 2012, DOI: 13385178
Abstract: Lactic acid bacteria (LAB) are nice targets in order to study γ-aminobutyric acid (GABA) production that has been reported to be effective in order to reduce blood pressure in experimental animals and human beings. In this study, we aimed to γ-aminobutyric acid (GABA) production in aerobical and anaerobical conditions, using different sources of microorganisms. The highest selectivity of GABA from precursor L-monosodium glutamate (82.22%) has been reported using of microorganisms from banana, and with addition of pyridoxal-5-phosphate (P-5-P). For augmentation of selectivity the application of the further stimulating factors of GABA biosynthesis is needed.
Production of gamma-aminobutyric acid by Lactobacillus brevis NCL912 using fed-batch fermentation
Haixing Li, Ting Qiu, Guidong Huang, Yusheng Cao
Microbial Cell Factories , 2010, DOI: 10.1186/1475-2859-9-85
Abstract: Pyridoxal-5'-phosphate did not affect the cell growth and gamma-aminobutyric acid production of Lb. brevis NCL912. Temperature, pH and initial glutamate concentration had significant effects on the cell growth and gamma-aminobutyric acid production of Lb. brevis 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-1 and 134.45 ± 24.22 mM at 48 h.A simple and effective fed-batch fermentation method was developed for Lb. brevis NCL912 to produce gamma-aminobutyric acid. The results reveal that Lb. brevis NCL912 exhibits a great application potential in large-scale fermentation for the production of gamma-aminobutyric acid.Gamma-aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in nature from microorganisms to plants and animals [1]. It acts as the major inhibitory neurotransmitter in the mammalian central nervous system. In addition, GABA has hypotensive, tranquilizing and diuretic effects, and can prevent diabetes [2-5]. Also, GABA may improve the concentration of plasma growth hormone and the rate of protein synthesis in the brain [6] and inhibit small airway-derived lung adenocarcinoma [7]. Therefore, GABA has potential as a bioactive component in foods and pharmaceuticals [8]. However, the direction addition of chemical GABA to food is considered unnatural and unsafe [8-10]. So it is necessary to find a natural method to produce and increase GABA in food.Recent studi
La fermentation éthanolique. Les microorganismes Ethanol Fermentation. The Microorganisms  [cached]
Ballerini D.,Blanchet D.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1987013
Abstract: Cette étude précise l'état actuel des connaissances concernant la fermentation éthanolique, d'un point de vue microbiologique. Outre les microorganismes utilisés depuis longtemps, sont décrites les nouvelles espèces de levures et de bactéries capables de transformer en éthanol des substrats aussi divers que les composés cellulosiques et hémicellulosiques issus de la biomasse et leurs produits d'hydrolyse. Pour la fermentation des substrats traditionnels tels que les mélasses et les jus d'extraction de plantes sucrières, ou encore l'amidon de ma s, les performances des levures du genre Saccharomyces sont comparées à celles des bactéries du genre Zymomonas. This review gives the state-of-the-art of what is known about ethanol fermentation from the microbiological viewpoint. In addition to the microorganisms that have been used for a long time, it describes new species of yeasts and bacteria capable of transforming, in ethanol, substrates including such different ones as cellulosic and hemicellulosic compounds issuing from biomass and their hydrolysis products. For the fermentation of traditional substrates such as molasses and juices extracted from sugar plants, or cornstarch, the performances of yeasts of the Saccharomyces type are compared to those of bacteria of the Zymomonas type.
Gamma-aminobutyric acid and GABAA receptors are involved in directional selectivity of pretectal neurons in pigeons
Quan Xiao,Yuxi Fu,Jing Hu,Hongfeng Gao,Shurong Wang
Science China Life Sciences , 2000, DOI: 10.1007/BF02879287
Abstract: The present study describes the effects of gamma-aminobutyric acid (GABA) and its antagonists, bicuculline and 2-hydroxysaclofen, on visual responses of neurons in the pigeon nucleus lentiformis mesencephali (nLM). The results indicate that GABA significantly reduces both spontaneous activity and visual responsiveness, and GABAA antagonist bicuculline but not GABAB antagonist 2-hydroxysaclofen enhances visual responses of nLM cells examined. Furthermore, inhibition produced by motion in the null-direction of pretectal neurons is diminished by bicuculline but not by 2-hydroxysaclofen. It is therefore concluded that the null-direction inhibition of directional cells in the pigeon nLM is predominantly mediated by GABA and GABAA receptors. This inhibition may at least in part underlie directional asymmetry of optokinetic responses.
Gamma-aminobutyric acid and GABAA receptors are involved in directional selectivity of pretectal neurons in pigeons

XIAO Quan,FU Yuxi,HU Jing,GAO Hongfeng,WANG Shurong,

中国科学C辑(英文版) , 2000,
Abstract: The present study describes the effects of gamma-aminobutyric acid (GABA) and its antagonists, bicuculline and 2-hydroxysaclofen, on visual responses of neurons in the pigeon nucleus lentiformis mesencephali (nLM). The results indicate that GABA significantly reduces both spontaneous activity and visual responsiveness, and GABAA antagonist bicuculline but not GABAB antagonist 2-hydroxysaclofen enhances visual responses of nLM cells examined. Furthermore, inhibition produced by motion in the null-direction of pretectal neurons is diminished by bicuculline but not by 2-hydroxysaclofen. It is therefore concluded that the null-direction inhibition of directional cells in the pigeon nLM is predominantly mediated by GABA and GABAA receptors. This inhibition may at least in part underlie directional asymmetry of optokinetic responses.
Upgrading the Fermentation Process of Zhejiang Rosy Vinegar by Purebred Microorganisms  [PDF]
Yujian Jiang, Sen Lin, Lei Zhang, Ping Yu
Advances in Microbiology (AiM) , 2013, DOI: 10.4236/aim.2013.33042
Abstract:

Purebred microorganisms were employed to upgrade the fermentation process of Zhejiang rosy vinegar. The fermentation cycle was greatly shorten from 5 months to 72 d. The transformation rate of raw materials was increased from 1:4.5 in the traditional fermentation to 1:5 or more in the upgraded fermentation. The content of organic acids in the traditional vinegar (TRV), the upgraded vinegar (UPV) and the submerged fermentation vinegar (SFV) were also investigated by HPLC. No significant difference was found regarding the proportion of phenylethanol to the total volatile components in UPV (7.47% ± 0.00324%) and TRV (7.23% ± 0.00329%), but it was significantly higher than that in SFV (2.26% ± 0.00143%). This study provides deep insight into upgrading the fermentation process of Zhejiang rosy vinegar by purebred microorganisms.

Secretion Of Methionine By Microorganisms Associated With Cassava Fermentation
N Anike, N Okafor
African Journal of Food, Agriculture, Nutrition and Development , 2008,
Abstract: Forty-six (46) bacteria were isolated from different sites associated with garri production from cassava: cassava pulp grated for garri production, grating machines, soil in the vicinity of the production of garri, and utensils involved in the processing of cassava into garri in several locations in Anambra State of Nigeria. Of these, Lactobacillus plantarum, Lactobacillus sp., Leuconostoc sp., Corynebacterium sp. and Bacillus sp. secreted methionine. The organisms were assessed for optimum methionine production at various levels of glucose, ammonium sulphate and varying mixtures of potassium hydrogen phosphate and di-potassium hydrogen phosphate. All the organisms required 10 g glucose for maximum methionine secretion. All the isolates required 20 g of (NH4)2SO4/litre, except for Bacillus sp. which required as little as 5 g of (NH4)2SO4/litre. The organisms' requirement for phosphate varied widely: the two lactobacilli required 0.5 g KH2PO4 and 1.5 g K2HPO4 per litre, Leuconostoc sp. and Bacillus sp. required 1.0 g KH2PO4 and 3.0 g K2HPO4 per litre. Lactobacillus spp. were the highest secreters of methionine, followed in that order by Leuconostoc sp., Corynebacterium sp. and Bacillus sp. The optimum period of incubation for the secretion varied from 48 h to 96 h, which is the period for cassava mash fermentation in garri production. The findings on Lactobacillus plantarum, Lactobacillus sp. and Leuconostoc sp. are of importance in any possible effort to increase the methionine content of garri. In this study the maximum quantities of methionine were secreted after 96 hours and 72 hours respectively by the lactobacilli and Leuconostoc sp. Since lactic acid bacteria are micro-aerophilic, it is suggested that lactic acid bacteria (the two lactobacilli and Leuconostoc sp.), which are the major organisms involved in cassava fermentation for garri production, may, in the less aerated environment of the cassava mash, produce more methionine and in shorter time, than observed under the aerobic conditions of this work.
Response surface modeling for y-aminobutyric acid production by Monascus pilosus GM100 under solid-state fermentation
B Sun, L Zhou, X Jia, C Sung
African Journal of Biotechnology , 2008,
Abstract: Monascus, a traditional Chinese fermentation fungus, is used as a natural dietary supplement. As a metabolite of Monascus, g-aminobutyric acid (GABA) had been proven to be a hypotensive agent. In this study, the ability of Monascus pilosus to produce GABA was investigated under solid-state fermentation. Plackett-Burman design (PBD) was applied to seek for the crucial parameters that affect the production of GABA. In addition, central composite design (CCD) was used to optimize each crucial variable. As a result, the maximum GABA production predicted by the CCD was 937.61 mg/kg using 60 g sterilized rice and 0.5% ethanol; optimum values of those crucial coefficients were determined to be monosodium glutamate (MSG) 0.714 (37.14 gkg-1), CaCl22H2O -0.025 (4.4625 gkg-1), and time of anaerobic treatment with CO2 (CO2 Time) -0.1947 (43.327 h). Under the theoretical optimal conditions, the actual GABA production was 884.32 mg/kg, approximately 4.9 times than that before optimization.
Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms  [PDF]
Virginia L. Pszczolkowski, Robert W. Bryant, Brittany E. Harlow, Glen E. Aiken, Langdon J. Martin, Michael D. Flythe
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.69070
Abstract: Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers’ yeast from large breweries has been used as a protein supplement in cattle; however the possible advantages of spent yeast from smaller craft breweries, containing much higher levels of bioactive hop acids, have not been evaluated. Hops secondary metabolites from the hops (Humulus lupulus L.) used to make beer are concentrated in the yeast during brewing, and have antimicrobial activity against Gram-positive bacteria. Uncultivated suspensions of bovine rumen microorganisms produced less methane during fructose fermentation when exposed to inactivated, and freeze-dried spent craft brewers’ yeast than a bakers’ yeast control. The experiment was repeated with caprine rumen microorganisms and ground grass hay as the substrate. Likewise, in the presence of craft brewers’ yeast less methane was produced (2.7% vs. 6.9% CH4). Both experiments also revealed a decrease in acetic acid production, but not propionic acid production, when craft brewers’ yeast was included. These results indicated that spent yeast could represent a co-product for craft breweries, and a feed supplement for ruminants that has a favorable impact on methane production.
Proliferation of Microorganisms in Acidic Fermentation of Elaeis guineensis L. Waste  [PDF]
M. Adedolapo Orimoloye, A. Isaac Sanusi
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.69063
Abstract: An investigation into the type of fermentation oil palm fruit waste undergoes and the probable microorganisms involved within a short period was carried out using simple fermenter. The temperature was determined using mercury thermometer, the pH of the medium was monitored with calibrated pH meter and the titratable acidic was determined using standard technique. The microbial profile of the medium was also evaluated using standard procedures. The highest temperature value was observed at day 0 (32.65°C) and the lowest at day 1 (29.50°C). The pH values of the fermentation oil palm fruit waste ranged between 4.15 - 4.60. The highest pH value was obtained at day 3 of the fermentation which was 4.60. The titratable acidity showed variation from day 0 - 2 and then with a continuous decrease till day 5. The least titratable acidity was obtained at day 5 (0.03) and the highest at day 2 (0.77). Bacteria load decreases from 1.0 × 108 - 1.6 × 107 cfu/ml, while the fungi population increases from day 0 to day 5 of the fermentation period (1 × 103 - 2 × 104 sfu/ml). Bacterial isolates obtained were Micrococcus leteus, Proteus vulgaris, Bacillus cereus, Baccillus subtilis, and Staphylococcus aureus while the fungal isolates obtained were Aspergillus niger, Neurospora crassa, Brachysporium spp,
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