Production Of L-glutamic Acid Research Articles

L-glutamic acid production by immobilized wild and mutant Bacillus species

The effect of Ultra-Violet (UV) irradiation and acridine orange dye on L-glutamic acid producing Bacillus subtilis and B. megaterium was investigated. The selected mutant strains and wild types of B. subtilis and B. megaterium were immobilized and used for L-glutamic acid production. The Bacillus strains were exposed to UV irradiation and treated with acridine orange dye respectively. The survived Bacillus strains were found to reduce as the exposure time and concentration of the mutagens increased in this study. Four mutants of B. subtilis and two mutants of B. megaterium were selected for L-glutamic acid production. Mutant strain of B. subtilis (MAIR4) treated with acridine orange dye yielded the highest L-glutamic acid (4.62 mg/mL) at 72 hours. L-glutamic acid production by mutant wild and strains of B. subtilis and B. megaterium immobilized on sodium alginate, Agar-agar matrix and poly urethane foam ranged from 1.65 to 4.03 mg/mL, 2.04 to 3.98 mg/ mL and 1.89 to 3.39 mg/mL, respectively with B. megaterium (MUSO17) on sodium alginate producing the highest L-glutamic acid. Sodium alginate was the best supporting matrix for the production of L-glutamic acid in this research. Immobilization of mutant strains of Bacillus megaterium (MASO17) exposed to UV irradiation using sodium alginate supported the L-glutamic acid production.

Effects of phenanthrene on the essential oil composition and leaf metabolome in peppermint plants (Mentha piperita L.)

Polycyclic aromatic hydrocarbons (PAHs) are an important type of persistent organic pollutant that endangers soil ecosystems and human health. Cultivating aromatic plants in PAH-contaminated soils is considered a safe and sustainable phytoremediation strategy to mitigate PAH soil pollution. However, the impact of PAHs on plant essential oils and the metabolic responses within aromatic plants remain unclear. In this study, we investigated the effects of the model PAH phenanthrene (Phe) on the chemical composition of essential oils in the ubiquitous aromatic plant peppermint (Mentha piperita L.) using gas chromatography-mass spectrometry (GC-MS). A total of 56 essential oil components were identified in the plants, among which the ratios of 21 components were significantly altered by Phe exposure. However, the fundamental components of peppermint essential oils including menthol, menthone, menthofuran, and pulegone did not exhibit considerable changes in levels. Thus, Phe stress may have little effect on the primary characteristics of peppermint essential oils. We also evaluated the effects of Phe treatment on metabolome dynamics within peppermint leaves by detecting metabolites in leaves treated with Phe for 0, 1, 3, 5, and 7 days (d) using non-targeted metabolomics. Compared with their corresponding control groups, 26 key different metabolites in the Phe-treated groups were identified and annotated via enrichment analysis with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Enriched metabolites were primarily involved in the oxidation of unsaturated fatty acids (UFAs), phenylpropanoid metabolism, amino acids, and the formation of vitamin C and caffeine. Phe treatment significantly promoted the oxidation of UFAs, phenylpropanoid metabolism, and histidine production in the first three days of Phe treatment. After 3 d, Phe gradually suppressed the oxidation of UFAs and L-glutamic acid production, while promoting phenylpropanoid metabolism, in addition to the synthesis of vitamin C and caffeine. The dynamic changes in metabolic pathway functioning in Phe-treated peppermint leaves reveal adaptive defensive mechanisms to mitigate Phe stress. This study provides new insights into the responses of aromatic plants toward PAH stress, while also providing a reference for the application of aromatic plants in the phytoremediation of PAH-contaminated soils.

Optimization of Culture Conditions for L-Glutamic Acid production by Bacillus flexus Using Response Surface Methodology

The body can use L-glutamic acid to make proteins (L-GA). It was formerly derived from plants, however bacteria have subsequently been studied as a potential source of synthesis. Bacillus flexus is a glutamic acid-harvesting bacteria that is well-known. Submerged fermentation was used in the production of L-GA. Response Surface Methodology (RSM) was utilized in this study to statistically optimize fermentation parameters that influence Bacillus flexus yield of L-glutamic acid. The effects of culture conditions, including several medium composition components, were evaluated using Central composite design (CCD) response surface optimization. Inoculum size, pH, substrate concentration, temperature, and time were all found to have substantial effects on glutamic acid production. Production increased considerably (p<0.05). Bacillus flexus produced the highest L-glutamic acid production of 4.9 g/L when the substrate concentration was 6%, the inoculum size was 4%, the temperature was 35°C, the pH was 7, and the time was 3 days, as predicted by RSM. This value is very close to the predicted value of 5.02 g/L, proving its validity. RSM proved to be a powerful strategy for improving this organism's L-glutamic acid synthesis.

Comparison Between the Predicted and Experimental L-Glutamic Acid Production by Free Cells Of Corynebacterium Glutamicum x680 Using Mathematical Model

The present investigation was undertaken to predict the amount of Lglutamic acid production by a mutant Corynebacterium glutamicum X680 using mathematical model emphasizing Bona and Moser (1997) hypotheses. This model was able to predict the experimental data with the minimum value of sum squares of weighted residues (sswr) 0.161. This model claimed that an increase in non-growth associated product formation coefficient led to maximum negative impact on L-glutamic acid production. Dhaka Univ. J. Biol. Sci. 31(1): 137-146, 2022 (January)

Enhanced L-glutamic acid production by immobilized Corynebacterium glutamicum X680 using Response Surface Methodology

L-glutamic acid is a non-essential amino acid largely used as flavor enhancer and food additive. It also has several therapeutic applications. Fermentation has gained superiority over its chemical synthesis as it produced stereo-specific isomer. Corynebacterium glutamicum is mostly used microorganism for Lglutamic acid fermentation. The study was dealing with optimization of L-glutamic acid production by immobilized mutant Corynebacterium glutamicum X680 in calcium alginate beads using response surface methodology as effective statistical tool. Among several parameters studied, pH, inoculums size, incubation time, concentration of sodium alginate, agitation and cell:alginate ration showed the most significant effect. Immobilized cells produced significantly (p<0.01) lower amount of L-glutamic acid (24.3mg/ml) compared to the production by free cells (27.6mg/ml). However, reusability of the beads minimized production cost and hence conferred benefit as far as the market economy is concerned.

High production of L-glutamic acid from date juice extracts by Corynebacterium glutamicum using fed-batch cultures: pulsed and continuous feeding modes

Abstract In the present work, L-glutamic acid production by Corynebacterium glutamicum fermentation on date juice extracts applying two fed-batch feeding modes, pulsed and continuous, were investigated. According to the obtained results, the continuous feeding fed-batch mode was found to be the most efficient process. Moreover the continuous feeding rate mode with a feeding medium containing date juice sugars enriched with ammonium sulfate was found even more favorable as it enhances the L-glutamic acid production by approximately 2.35 fold more than the batch culture and by about 1.17 fold more than the pulsed feeding. In this respect, comparing the traditional batch culture to the continuously fed culture with a medium containing date juice sugars with ammonium sulfate showed increases of 135.47% in L-glutamic acid production, 104% in productivity, 39.09% in biomass, and 47.69% in the yield respectively allowing us to reach a final L-glutamic acid concentration of about 138 g/L, the highest ever published.

Small Scale Laboratory Culture Method Production and Characterization of L-Glutamic Acid by E.Coli

Small Scale Laboratory Culture Method Production and Characterization of L-Glutamic Acid by E.Coli

Optimization of glutamic acid production by Corynebacterium glutamicum using response surface methodology

The body to build proteins can use l-Glutamic acid (l-GA). Earlier it was obtained from plant sources, later on microbes have been explored for the production. Corynebacterium glutamicum is a prominent organism used to harvest the glutamic acid. Submerged fermentation was adopted for l-GA production. Various nitrogen/carbon substrates used to find out the best nitrogen and carbon source. Statistical methods especially RSM (response surface method) stayed employed for the effect of various factors such as inoculum size, urea, glucose and salt on the l-GA production. As per the preliminary studies, urea and glucose were chosen as carbon and nitrogen sources. Further, the optimum values have been maximally documented in the glucose (50 g/L), then urea (10 g/L), 19.24% of salt solution and 5% of inoculum size. Maximum Yield of l-GA is produced through RSM-16.49 g/L. The experimental l-Glutamic acid production was 16.36 g/L at an optimum condition that compared well to the maximum predicted values by RSM (16.499 g/L). Non-linear regression quadratic model was developed for the l-GA synthesis; the methodology was validated statistically and the determination coefficient (R2) was found to be 0.991. Thus the study identified the potential carbon and nitrogen source for a higher yield for l-GA using C. glutamicum under submerged fermentation and also this method minimizes the time for optimizing the medium components statistically.

Engineering Corynebacterium glutamicum for the de novo biosynthesis of tailored poly-γ-glutamic acid

γ-Polyglutamic acid (γ-PGA) is a biodegradable polymer naturally produced by Bacillus spp. that has wide applications. Fermentation of γ-PGA using Bacillus species often requires the supplementation of L-glutamic acid, which greatly increases the overall cost. Here, we report a metabolically engineered Corynebacterium glutamicum capable of producing γ-PGA from glucose. The genes encoding γ-PGA synthase complex from B. subtilis (pgsB, C, and A) or B. licheniformis (capB, C, and A) were expressed under inducible promoter Ptac in a L-glutamic acid producer C. glutamicum ATCC 13032, which led to low levels of γ-PGA production. Subsequently, C. glutamicum F343 with a strong L-glutamic acid production capability was tested. C. glutamicum F343 carrying capBCA produced γ-PGA up to 11.4 g/L, showing a higher titer compared with C. glutamicum F343 expressing pgsBCA. By introducing B. subtilis glutamate racemase gene racE under Ptac promoter mutants with different expression strength, the percentage of L-glutamic acid units in γ-PGA could be adjusted from 97.1% to 36.9%, and stayed constant during the fermentation process, while the γ-PGA titer reached 21.3 g/L under optimal initial glucose concentrations. The molecular weight (Mw) of γ-PGA in the engineered strains ranged from 2000 to 4000 kDa. This work provides a foundation for the development of sustainable and cost-effective de novo production of γ-PGA from glucose with customized ratios of L-glutamic acid in C. glutamicum.

Screening of different Pseudomonas and Bacillus Spp. for production of L-glutamic acid and impact of their cell-free filtrate on growth and yield of brinjal (Solanum melongena)

Amino acids can play a different role in plants such as nitrogen source, hormonal precursor and stress reducing agents. L glutamic acid is involved in several plant metabolic processes. The objectives of present work were to evaluate the L glutamic acid production by different agriculturally important Pseudomonas and Bacillus species and to determine the effects of L glutamic acid containing cell-free filtrate on growth and yield of brinjal. An experiment was conducted in a completely randomized block design (CRBD). Out of eight different strains of Pseudomonas, the highest L glutamic acid was detected in Pseudomonas fluorescens 128 (1.397 g/l) followed by Pseudomonas fluorescens NSPL07 (1.073 g/l) and Pseudomonas striata RCOF153 (0.563 g/l). Similarly, out of six different species of Bacillus, moderate L glutamic was detected in Bacillus amyloliquefaciens MTCC10439 (0.232 g/l). The growth stimulatory effects of L glutamic acid containing filtrate (200 ppm) was also studied and it was found that all growth parameters of brinjal (plant height, fruits per plant, fruit yield etc) improved significantly. Results indicated that bacterial secretion containing L glutamic acid along with other amino acids have bio-stimulatory effects and it should be used to enhance the plant growth and yield.

Isolation, characterization and improvement on a wild strain of Corynebacterium glutamicum for L-glutamic acid production

Isolation, characterization and improvement on a wild strain of Corynebacterium glutamicum for L-glutamic acid production

Effects of proteases on L-glutamic acid fermentation

ABSTRACT In the process of L-glutamic acid fermentation, there are proteins that cannot be decomposed and utilized by bacteria and that secreted by bacteria at the same time, which cause problems such as increased foam production in the fermentation broth that lowers the dissolved oxygen, which makes the total fermentation efficiency low. Therefore, these proteins can be decomposed by adding proteases in the fermentation broth, and it is found that the best results are obtained by adding 0.5 g/L of trypsin. Proteins can be used by bacteria after being decomposed as well. The final L-glutamic acid production in our research was 177.0 g/L, which is 14.9% more than the control fermentation (154.0 g/L). Similarly, the glucose conversion rate was 68.3%, which is an increase of 4.0% as compared to the control fermentation (65.6%).

Statistical optimization of the culture conditions for L-glutamic acid production by a mutant Micrococcus glutamicus AB100

Statistical optimization of the culture conditions for L-glutamic acid production by a mutant Micrococcus glutamicus AB100

A Study of Naturally-occurring L-glutamic Acid Producing Bacteria From Tropical Soil and Aquatic Environments.

Microbial means of L-glutamic acid production haveadvantage of directly yielding optical and biological active form of the aminoacid. The production of L-glutamic acid was investigated using bacterialisolates obtained from tropical soil and water samples obtained from Lagos,Nigeria. L–glutamic acid producing bacterial strains were isolated andidentified using the Analytical Profile Index (API) Test 50CHB/20E kit. TheL-Glutamic acid production was tested on Luria Bertani Broth and determined byqualitative and quantitative approaches. Six (6) isolates were L-Glutamateproducers of which the best producing isolates were Paenibacillus alvei and Corynebacteriumglucuronolyticum – seminale giving a yield higher than 0.7 g/L. The best L-glutamic acid producing isolateswere further tested to determine the effects of a variety of carbon andnitrogen sources as well as varying concentration of biotin on the yield of theamino acid produced. Glucose gave yields of 1.19 g/L and 1.05 g/L of L-glutamicacid for Paenibacillus alvei and Corynebacterium glucuronolyticum–seminale respectively,while ammonium chloride and optimum biotin concentration at 2µg gave yields of1.15 g/L and 2.09 g/L as well as 1.59 g/L and 1.75 g/L respectively. Thesebacterial strains therefore offer tremendous promise as candidates for furthermanipulation for enhanced production of L-glutamic acid using indigenousbacteria from the tropical environment

Effect of osmotic stress on l-glutamic acid production by an auxotrophic mutant Micrococcus glutamicus AB100

An experimental study was carried out to examine the effect of osmotic stress on L-glutamic acid production by the mutant Micrococcus glutamicus AB 100 . Initial addition of NaCl resulted in an arrest of the bacterial cell growth and glucose consumption. The cell growth was found to resume within few hours. Maximum cell growth was obtained with 1.0 (M) NaCl. Micrococcus glutamicus AB 100 was found to grow even with 2.0(M) -3.0(M) NaCl.

Dynamics and control of continuous reactive crystallization processes

Control of two continuous reactive crystallization processes, one for the production of barium sulfate and one for the production of L-glutamic acid, is investigated. In both processes, the crystal mass production rate and the volume mean size of the product are controlled by manipulating the reactant inlet volumetric flow rates and the holdup in the crystallizer. The reactant inlet concentration, nucleation rate, and temperature of the crystallizer are considered as disturbances. The control structures provide good performance for 10% changes in disturbance variables and setpoint changes. Furthermore, stability analysis is performed for both processes and operating regions where continuous oscillations in solute concentration and crystal size distribution can occur are identified.

Seeding and Optimization of Batch Reactive Crystallization

Conceptual methods are illustrated for the development of operating policies for batch reactive crystallization processes. Two processes, production of barium sulfate and production of l-glutamic acid, are studied. For barium sulfate, the critical seed loading ratio is found to be above the practical limit, which suggests that seeding cannot be employed to suppress nucleation. Conversely, for l-glutamic acid, the critical seed loading ratio is below the practical limit for a wide range of seed sizes, suggesting that seeding can be used to suppress nucleation almost entirely. These results are verified by rigorous process simulation. Furthermore, for the barium sulfate process, a plot of nucleation rate B versus growth rate G is concave, indicating that an early growth trajectory (with supersaturation highest at the beginning of the batch) will minimize the nucleated mass, while for the l-glutamic acid process the plot is convex, indicating that a late growth trajectory will minimize the nucleated mass. Th...

Evaluation of factors that influence the L-glutamic and γ-aminobutyric acid production during Hericium erinaceus fermentation by lactic acid bacteria

Fermented plant beverages (FPBs) are non-alcoholic and are produced by lactic acid bacteria (LAB) with different edible plant sources. Owing to the lack of a detailed study on fermented Hericium erinaceus with LAB, the current study was employed to exploit and optimize the fermentation condition for the production of L-glutamic acid (GA)- and γ-aminobutyric acid (GABA)-rich fermented H. erinaceus beverage by Lactobacillus brevis HP2 and Lactobacillus fermentum HP3, respectively. Box–Behnken design (BBD) for response surface methodology was employed with cofactor, pH and temperature as independent variables. The results suggested that L. brevis HP2 and L. fermentum HP3 are good starter cultures for H. erinaceus fermentation with enriched GA and GABA production. In this case, GA production was significantly influenced by K2HPO4, pH and temperature whereas GABA production was significantly influenced by pH and temperature. Further thorough and fine optimization is required to fabricate high-quality fermented drinks with low cost.

Production of L (+) Glutamic Acid in a Fully Membrane-Integrated Hybrid Reactor System: Direct and Continuous Production under Non-Neutralizing Conditions

Experimental investigations were carried out on continuous and direct production of l-glutamic acid in a hybrid reactor system that integrated a conventional fermentative production step with downstream membrane-based separation and purification in flat sheet cross-flow membrane modules. To ensure constant fermentor capacity, the system was operated at steady state at different set flux values ranging from 76 L m–2 h–1 to 90 L m–2 h–1 at a dilution rate of 0.15 h–1. Overcoming the substrate–product inhibitions of traditional batch production system, this new, compact, flexible, and largely fouling-free design ensured steady and continuous production of l-glutamic acid directly from a renewable carbon source at the rate of about 8.4 g L–1 h–1. Provisions of continuous product withdrawal, separation, and recycling of unconverted sugar and microbial cells ensured almost inhibition-free production under high cell concentration. Well-screened nanofiltration membranes with high selectivity helped achieve over 97% product purity while ensuring recovery and recycle of more than 95% unconverted carbon source resulting in a high yield of 0.95 g g–1. The direct production scheme involves no phase change and use of harsh chemicals. The study presents development of a green process of glutamic acid production for sustainable business.

MODELING AND OPTIMIZATION OF GLUTAMIC ACID PRODUCTION USING MIXED CULTURE OF Corynebacterium glutamicum NCIM2168 AND Pseudomonas reptilivora NCIM2598

In this study, a hybrid system of response surface methodology followed by genetic algorithm has been adopted to optimize the production medium for L-glutamic acid fermentation with mixed cultures of Corynebacterium glutamicum and Pseudomonas reptilovora. The optimal combination of media components for maximal production of L-glutamic acid was found to be 49.99 g L−1 of glucose, 10 g L−1 of urea, 18.06% (v/v) of salt solution, and 4.99% (v/v) of inoculum size. The experimental glutamic acid yield at optimum condition was 19.69 g L−1, which coincided well to the value predicted by the model (19.61 g L−1). Using this methodology, a nonlinear regression model was developed for the glutamic acid production. The model was validated statistically and the determination coefficient (R 2) was found to be 0.99.