Glycine Medium Research Articles

Biodiversity and biological applications of marine actinomycetes—Abu-Qir Bay, Mediterranean Sea, Egypt

BackgroundThe ability of actinomycetes to produce bioactive secondary metabolites makes them one of the most important prokaryotes. Marine actinomycetes are one of the most important secondary metabolites producers used for pharmaceuticals and other different industries. ResultsIn this study, the promising actinomycetes were isolated from Abu-Qir Bay. Four different media named as starch nitrate, starch casein, glycerol asparagine, and glycerol glycine were used as a preliminary experimental media to study the role of the medium components on the counts of actinomycetes in sediment samples. The results indicated that starch casein medium reported the highest counts (30–63 CFU/g) in all the tested sites. Lower counts were detected on starch nitrate and glycerol asparagine. On the other hand, glycerol glycine medium gave the lowest counts (15–48 CFU/g). Abu-Qir8 harbored the highest average count of actinomycetes (63 CFU/g), followed by Abu-Qir1 (48 CFU/g). The lower counts were detected in Abu-Qir5 and Abu-Qir7 (26 and 29 CFU/g, respectively). A total of 12 pure obtained actinomycetes isolates were subjected to morphological, physiological, and biochemical characterization. The selected actinobacterial isolates were subjected to numerical analysis, and the majority of isolates were grouped into four main clusters (A, B, C, & D), and each of them harbored two isolates; additionally, four isolates did not cluster at this similarity level. Isolate W4 was carefully chosen as the most promising pigment and antimicrobial agent’s producer; the produced pigment was extracted and optimized by statistical experiments (PBD & BBD) and was tested for its anti-inflammatory activity. The results showed anti-inflammatory effect and prevented the denaturation of BSA protein at a concentration much higher than the safe dose and increased with increasing the pigment concentration. ConclusionMarine actinomycetes play a vital role in the production of novel and important economic metabolites that have many industrial and pharmaceuticals applications. Streptomyces genera are the most important actinomycetes that produce important metabolites as previously reported.

The effect of structural properties of benzo derivative on the inhibition performance for copper corrosion in alkaline medium: Experimental and theoretical investigations

As the most commonly used multilayer interconnect metal material of integrated circuits, copper corrosion inhibition is a key technical problem in chemical mechanical polishing (CMP). Many organic compounds represented by benzo derivatives have been widely studied as copper corrosion inhibitors in CMP slurry. In this study, the adsorption performance and inhibition mechanism of three benzo derivatives (BI, BTA, and MBI) on copper in glycine medium under alkaline conditions were studied by experimental and theoretical methods to explore the influence of the molecular structure of the inhibitors on the corrosion inhibition performance. The electrochemical results and gravimetric methods show that the three organic molecules are mixed inhibitors, and the order of inhibition efficiency for copper is BTA > MBI > BI. The increase of contact angle on the copper surface confirmed the adsorption of hydrophobic inhibitors on the copper surface. Atomic force microscope and scanning electron microscope tests further confirmed this. X-ray photoelectron spectroscopy reveals that the three inhibitors can form inhibitor adsorption film on the copper surface, indicating that they have excellent corrosion inhibition properties. In addition, the electronic properties and reactive sites for the interaction with the copper surface were identified by quantum chemical calculation. Molecular dynamics simulation was used to investigate the most stable configuration of the inhibitor molecules on the Cu (111) surface in aqueous medium and to explain the results of molecular-level experiments.

Cyclic voltammetry and potentiodynamic polarization studies of chalcopyrite concentrate in glycine medium

Cyclic voltammetry and potentiodynamic polarization analyses were utilized to investigate the mechanism and kinetics of glycine leaching reactions for chalcopyrite. The effects of pH (9–12), temperature (30–90 °C) and glycine concentration (0–2 mol/L) on corrosion current density, corrosion potential and cyclic voltammograms were investigated using chalcopyrite concentrate–carbon paste electrodes. Results showed that an increase in the glycine concentration from 0 to 2 mol/L led to an increased oxidation peak current density. Under the same conditions, corrosion current density was found to change from approximately 28 to 89 μA/cm b whereas corrosion potential was decreased from –80 to –130 mV. Elevated temperatures enhanced the measured current densities up to 60 °C; however, above this level, current density was observed to decrease. A similar current density behavior was determined with pH. A pH change from 9 to 10.5 resulted in an increase in current density and pH higher than 10.5 gave rise to a reduced current density. In addition, the thermodynamic stability of copper and iron oxides was found to increase at higher temperatures.

Investigation into the effect of mechanical activation on the leaching of chalcopyrite in a glycine medium

The effect of mechanical activation on the leaching and electrochemistry of chalcopyrite was investigated in a glycine medium. Leaching experiments were conducted to evaluate the effect of particle size (with re-ground sample in ball mill) and mechanical activation (with re-ground sample in planetary mill for 4 h) on chalcopyrite dissolution in a stirred tank reactor. Results show that a maximum copper extraction (95.1%) was obtained for mechanically activated chalcopyrite after 12 h leaching in a 0.4 M glycine solution at 60 °C, 2% (w/v) pulp density and an initial solution pH of 10.5. Under these same leaching conditions, a decrease in particle size for conventionally ground chalcopyrite from 106 to 125 μm to <20 μm, led to a substantial increase in the level of copper extraction - from 0.6% to 33.8%. Analysis of solid residue by XRD showed that iron could be precipitated as maghemite and a part of dissolved copper could be removed from the solution as copper glycinate crystals and covellite. Result of the electrochemical analysis showed that the anodic current of the chalcopyrite‑carbon paste electrode was significantly increased for the mechanically activated sample. Nevertheless, anodic current densities were observed to reduce during subsequent voltammetry cycles as a consequence of passivating the surface of chalcopyrite electrode by reaction products and decreasing electroactive cites the electrode surface. A new 2-stage leaching flowsheet was proposed to extract copper from chalcopyrite concentrates in glycine media. Glycine leaching with mechanical activated pretreatment could be a promising method for treating low-grade chalcopyrite concentrates.

Glycine leaching of Sarcheshmeh chalcopyrite concentrate at high pulp densities in a stirred tank reactor

The simplest amino acid, glycine has recently been reported as a safe and environmentally benign reagent for the extraction of copper from both oxide and sulfide minerals. In the current study, leaching of a chalcopyrite concentrate from the Sarcheshmeh Copper Mine (Kerman, Iran) was conducted in stirred tank reactors in the presence of a glycine medium. The effect of some critical leaching parameters including glycine concentration (0.4–2 M), temperature (30–90 °C), stirring rate (250–750 rpm), pH (9–12), oxygen flowrate (0.5–2 L/min) and pulp density (1–20%) was investigated on copper recovery from the chalcopyrite concentrate. Results show that an increase in temperature from 30 to 60 ˚C enhanced the copper extraction, whereas at conditions > 60 ˚C a decrease in copper extraction was observed, probably as a result of the conversion of glycine to glycinate and decrease in oxygen solubility. Moreover, prolonged leaching times at higher pH levels (10.5 and 12) led to a decrease in the extraction of copper, primarily due to the chemical precipitation of copper sulfide and crystallization of copper glycinate. By increasing the pulp density from 1 to 20%, copper extraction declined significantly primarily as a consequence of the partial dissolved copper precipitation at higher copper concentrations. SEM/WDX analyses were subsequently used in order to evaluate the leach residues. Further investigation determined that the activation energy of the glycine leaching of concentrate was 37.4 KJ/mol, thus the kinetics were controlled by diffusion of the reagents through the product layer. From these results, it is evident that due to the high initial rate of glycine leaching and the precipitation of copper-bearing phases (i.e. copper glycinate and covellite) at high pulp densities, glycine leaching processes are recommended for the treatment of low grade chalcopyrite concentrates, ores or tailings.

Effect of adding amino acids on the production of Gamma-Aminobutyric Acid (GABA) by mycelium of Lentinula edodes

Abstract This study was carried out to investigate the production of a health functional food component through the production of GABA by mycelium of Lentinula edodes (LE) cultured in a medium containing four different amino acids. To confirm the GABA content in the medium, the amount of GABA produced by adding 0.1 M of glutamic acid, alanine, glycine, or lysine to Potato Dextrose Agar (PDA) medium and Potato Dextrose Broth (PDB) medium was determined. The amount of mycelia in the PDB medium was 4.85 g/L in the amino acid-free medium, 5.12 g/L in the glutamic acid medium, 4.63 g/L in the alanine medium, 4.87 g/L in the glycine medium, and 4.18 g/L in the lysine medium. The amount of amino acid added to the medium did not interfere with the normal growth of LE because the amount of excess amino acid was not significantly different from that of the control. The GABA content was 10.35 mg/L in the control (amino acid-free), 30.29 mg/L in the glutamic acid supplemented medium, 11.70 mg/L in the alanine supplemented medium, 10.62 mg/L in the glycine supplemented medium and 3.96 mg/L in Lysine supplemented medium. These results show that the excess glutamic acid had the highest level of GABA in the mushroom culture medium. On the other hand, it was confirmed that the addition of excess alanine and glycine did not affect the GABA production compared to the control. These results suggest that continuous GABA production could not be achieved by using an ion exchange resin after the disruption of GABA production by biological methods, however, continuous GABA production using the mycelium of LE is possible in this study.

Conductometric Studies on Micellization of Cationic Surfactants in the Presence of Glycine

Values of the critical micelle concentration (cmc) and degree of counterion dissociation (α) of four cationic surfactants: cetyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC) and benzyldimethylhexadecylammonium chloride (BDHAC) in aqueous–glycine medium (concentration of glycine (Gly) varied from 0 to 0.20 mol·dm−3) were determined through conductometric measurements at 303 K. The effect of temperature on the micellization in the presence of 0.10 mol·dm−3 Gly were studied for the surfactants CTAB, CPC and BDHAC. With respect to the concentration of Gly, a decrease in the cmc was observed for CTAB, CPC and CPB whereas an increase was observed for BDHAC. A regular increase in α was obtained for CPB, CPC and BDHAC with respect to the concentration of Gly whereas values were roughly constant in the case of CTAB. Thermodynamic parameters were computed from the temperature dependence of the cmc values and it was found that the micellization process is exothermic. Compensation of enthalpy and entropy was observed for the micellization of CTAB, CPC and BDHAC in the presence of 0.10 mol·dm−3 Gly.

Analytical application of poly [dibenzo-18-crown-6] for chromatographic separation of thorium(IV) from uranium(VI) and other elements in glycine medium

A selective and effective chromatographic separation method for thorium(IV) has been developed by using poly [dibenzo-18-crown-6] as stationary phase. The separations are carried out from glycine medium. The sorption of thorium(IV) was quantitative from 1 × 10−2 to 1 × 10−4 M glycine. The elution of thorium(IV) was quantitative with 2.0–8.0 M HCl, 4.0–7.0 M HBr, 1.0–2.0 M HClO4 and 5.0 M H2SO4. The capacity of poly [dibenzo-18-crown-6] for thorium(IV) was found to be 0.215 ± 0.01 mmol/g of crown polymer. The effect of concentration of glycine, metal ion, foreign ion and eluents has been studied. Thorium(IV) was separated from a number of cations in ternary as well as in multicomponent mixtures. The applicability of the proposed method was checked for the determination of thorium(IV) in real as well as geological sample. The method is simple, rapid, and selective with good reproducibility (approximately ±2 %).

Fungal C translocation restricts N‐mineralization in heterogeneous environments

Summary 1. In forest soils, fungi generally dominate the decomposer community, but their specific, filamentous physiology is often not recognized in nitrogen (N) cycling models. Many litter degrading fungi form large mycelia and have a well‐developed capacity to translocate resources within their mycelia. Fungi may thus connect substrates that differ with respect to carbon (C) and nitrogen (N) availability and, thereby, overcome local resource limitation through translocation. 2. Here we test whether the ability of fungi to translocate carbohydrates within their mycelia prevents local C limitation in a low C:N ratio substrate, thereby reducing N mineralization. The capacity of fungi to translocate N to a high C:N ratio substrate in order to increase the decomposition, was also assessed. Two litter decomposing fungi, Marasmius androsaceus and Mycena epipterygia were grown in axenic laboratory microcosms containing spatially separated substrates: pine needles (C:N = 135) and glycine (C:N = 2). 3. In the absence of needles both fungi mineralized the glycine N. When connecting the two substrates, both fungi were able to overcome local C‐deficiency on the glycine medium by translocating carbohydrates from the needles. In the presence of needles, N mineralization from glycine was negligible, although the glycine was utilized. Only trace amounts of N were translocated from glycine to the needles. 4. A basic assumption of N cycling models is that substrates of different qualities decompose in an independent manner. Our observations imply that this assumption may be violated in heterogenic environments dominated by fungi.

Growth and Pigment Production on d -Tryptophan Medium by Cryptococcus gattii , Cryptococcus neoformans , and Candida albicans

Given the increasing prevalence of cryptococcosis caused by Cryptococcus gattii (serotypes B and C) strains, there is a need for rapid and reliable tests that discriminate C. gattii from Cryptococcus neoformans (serotypes A, D, and AD). Seventy-two C. neoformans strains, sixty-seven C. gattii strains, and five Candida albicans strains were analyzed for their ability to grow and produce pigment on minimal D-tryptophan D-proline (m-DTDP) medium, on yeast carbon base D-tryptophan D-proline (YCB-DTDP) medium, and on fructose D-tryptophan glycine (m-FDTG) medium. Of the C. gattii and C. neoformans isolates, 94% and 0% grew on m-DTDP agar, respectively, and 98% and 0% grew in YCB-DTDP medium, respectively. C. gattii produced large amounts of brown intracellular pigment(s) on m-DTDP agar and smaller amounts of yellow-brown (amber) extracellular pigment(s). C. albicans grew on both media and produced a pink photoactivated pigment on m-DTDP agar. C. gattii produced large amounts of brown intracellular pigments on the differential medium m-FDTG, whereas C. neoformans produced smaller amounts of the brown pigments and C. albicans produced a pink pigment. The pigments produced by C. gattii from D-tryptophan were distinct and were not related to melanin formation from 3,4-dihydroxyphenylalanine. Thin-layer chromatography of the methanol-extracted C. gattii cells detected four different pigments, including brown (two types), yellow, and pink-purple compounds. We conclude that tryptophan-derived pigments are not melanins and that growth on m-DTDP or YCB-DTDP agar can be used to rapidly differentiate C. gattii from C. neoformans.

Diffusion and Not Active Transport Underlies and Limits ERK1/2 Synapse-to-Nucleus Signaling in Hippocampal Neurons

The propagation of signals from synapses and dendrites to the nucleus is crucial for long lasting adaptive changes in the nervous system. The ERK-MAPK pathway can link neuronal activity and cell surface receptor activation to the regulation of gene transcription, and it is often considered the principal mediator of synapse-to-nucleus communication in late-phase plasticity and learning. However, the mechanisms underlying ERK1/2 trafficking in dendrites and nuclear translocation in neurons remain to be determined leaving it unclear whether ERK1/2 activated at the synapse can contribute to nuclear signaling and transcriptional regulation. Using the photobleachable and photoactivable fluorescent tag Dronpa on ERK1 and ERK2, we show here that ERK1/2 translocation to the nucleus of hippocampal neurons is induced by the stimulation of N-methyl-D-aspartate receptors or TrkB stimulation and is apparently mediated by facilitated diffusion. In contrast, ERK1/2 trafficking within dendrites is not signal-regulated and is mediated by passive diffusion. Within dendrites, the reach of a locally activated pool of ERK1/2 is very limited and follows an exponential decay with distance. These results indicate that successful signal propagation to the nucleus by the ERK-MAPK pathway depends on the distance of the nucleus from the site of ERK1/2 activation. ERK1/2 activated within or near the soma may rapidly reach the nucleus to induce gene expression, whereas ERK1/2 activated at distal synapses may only contribute to local signaling.

Differentiation of Malassezia furfur and Malassezia sympodialis by glycine utilization

The genus Malassezia has been revised to include six lipophilic species and one nonlipophilic species. These Malassezia species have been investigated to differentiate their morphological and physiological characteristics. However, assimilation of amino acids as a nitrogen source by these species was not well elucidated. In the present study, isolates of Malassezia species were examined with a glycine medium (containing 7-266 mmol glycine, 7.4 mmol KH(2)PO(4), 4.1 mmol MgSO(4)7H(2)O, 29.6 mmol thiamine, 0.5% Tween-80 and 2% agar) and a modified Dixon glycine medium (0.6% peptone, 3.6% malt extract, 2% ox-bile, 1% Tween-40, 0.2% glycerol, 0.2% oleic acid, 7 mmol glycine and 2% agar). All M. furfur isolates developed on the glycine medium, assimilating glycine at concentrations of at least 7 mmol l(-1). However, the other six Malassezia species were unable to grow on the glycine medium. Also, many colonies of M. furfur grew rapidly, within 2-3 days on the modified Dixon glycine medium, although the other six species showed slow and poor development. From these results, it was suggested that M. furfur might be able to utilize glycine as a single nitrogen source, which the other Malassezia species could not. Therefore, glycine medium was recommended for the differentiation of M. furfur from other species of Malassezia.

Toxic effects of Hg 2+ to a Hg 2+-resistant Pseudomonas in the presence of halide ions

A Hg 2+-resistant Pseudomonas which can utilize glycine as a sole carbon and nitrogen source was isolated from a municipal sewage treatment plant, and the toxicity of Hg 2+ in the presence of halide ions was examined. In glycine medium without halide ions, bacterial growth was scarcely influenced even at an initial Hg 2+ concentration of 25 μM. The viable cell count decreased when adsorbed Hg 2+ was more than 300 μmol·g-cell −1. The toxicity of Hg 2+ was enhanced when the halide ion concentration was such that the [HgX 2] 0 complex ( X=Br − or I −) in the solution became dominant. In the presence of [HgBr 2] 0 complex, complete growth inhibition of unacclimatized cells was observed at 2–3 μM Hg 2+. A sudden decrease in the viable cell count was evident when adsorbed Hg 2+ was more than 15 μmol·g-cell −1. Growth of the isolate pre-incubated in glycine medium containing 25 μM Hg 2+ (acclimatized cells) was also inhibited completely at 10 μM Hg 2+ in the presence of Br −. The adsorption and toxicity of Hg 2+ decreased with increasing halide ion concentration in which [HgBr 3] − or [HgBr 4] 2− complexes exist dominantly. These results indicate that toxicity of Hg 2+ was enhanced by the formation of [HgX 2] 0 complex and was not governed by the amount of Hg 2+ adsorbed to the cells.

Toxic effects of mercuric ion on the growth of Chlorella sp. in glycine medium : Mitsuo Kuriyama, Hiroyuki Matsunaga, Takashi Shirakashi, and Kazuo Kakii ( Department of Environmental, Chemistry, Faculty of Engineering, Utsunomiya University, Ishii-cho, Utsunomiya, 321, Japan) Hakkokogaku 66: 157–162. 1988

Toxic effects of mercuric ion on the growth of Chlorella sp. in glycine medium : Mitsuo Kuriyama, Hiroyuki Matsunaga, Takashi Shirakashi, and Kazuo Kakii ( Department of Environmental, Chemistry, Faculty of Engineering, Utsunomiya University, Ishii-cho, Utsunomiya, 321, Japan) Hakkokogaku 66: 157–162. 1988

Medium to Culture and Differentiate Coagulase-Positive and -Negative Staphylococci from Bovine Milk

A medium which incorporates CAMP factor produced by Streptococcus agalactiae (group B) into sheep blood agar was used to culture and identify coagulase-positive staphylococci from bovine milk. Of 506 staphylococcal isolates from bovine milk, 92.5% of coagulase-positive organisms produced a wide zone of complete hemolysis, whereas 98.9% of coagulase-negative organisms did not. The agreement of this one-step culture and identification test with the standard tube coagulase test was higher than that of the deoxyribonuclease test medium, Baird-Parker egg yolk medium, tellurite glycine medium and slide coagulase tests.

The biosynthesis of n‐[2H7] fatty acids byArthrobacter globiformis from [U‐2H15] octanoic acid

The principal fatty acids present whenArthrobacter globiformis is grown on a glycine medium free of normal fatty acids were found to be the C15 and C16 anteiso fatty acids; only a small amount of the normal fatty acids (C14 and C16) were present. Cells grown on the same medium but supplemented mented with 0.1 mg/ml [U-(2)H(15)]octanoic acid were found to contain an increased amount of the normal fatty acids and these fatty acids were found to be labeled with 7 deuteriums. I concluded that the octanoic acid is degraded by β-oxidation in these cells to [U-(2)H(7)] butyryl-CoA, which then competes with 2-methylbutyryl-CoA for the initiation of fatty acid biosynthesis.

Separation of Th(lV) in Aqueous Glycine Medium by Cation Exchange Chromatography

Separation of Th(lV) in Aqueous Glycine Medium by Cation Exchange Chromatography

Cell cycle-specific reactivation of an inactive X-chromosome locus by 5-azadeoxycytidine.

Three cytidine analogs containing modifications in the 5-position of the cytosine ring (5-azacytidine, 5-aza-2'-deoxycytidine and pseudoisocytidine) induced the expression of human hypoxanthine/guanine phosphoribosyltransferase (IMP; pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) gene (HPRT) from a structurally normal inactive human X chromosome retained in a mouse-human somatic cell hybrid. Between 0.1% and 8% of the cells surviving treatment with these analogs were able to form colonies in selective medium (hypoxanthine/aminopterin/thymidine/glycine medium), but two other analogs, 5-fluoro-2'-deoxycrytidine and 5.6-dihydro-5-azacytidine, did not induce HPRT expression. The inactive X chromosome present in the hybrid, was found to be late replicating, and experiments with synchronized cells showed that the induction of HPRT expression by 5-aza-2'-deoxycytidine occurred maximally in cells treated in the latter half of the S phase. Two division cycles were required after analog treatment for the highest frequency of expression of the induced gene. Because these analogs are powerful inhibitors of the methylation of cytosine residues in DNA, the results imply that demethylation of specific DNA sequences may be required for the reexpression of human HPRT.

Ｃｈｌｏｒｅｌｌａ ｓｐ（Ｃｓ）の増殖特性，特にＢ．ｍｅｇａｔｅｒｉｕｍ（Ｂｍ）との共生による増殖

Growth characteristics of Chlorella sp. isolated from a sedimentation tank in glycine, glucose and inorganic medium and also in peptone medium in association with B. megaterium were discussed. Chlorella sp. utilized glycine phototrophycally and specific growth rate (μ) was 3.35 day-1 (25°C). The isolate also utilized small amount of glycine heterotrophycally (under dark and the supply of air) and specific growth rate (μ) was 2.76 day-1. The isolate utilized glucose heterotrophycally (μ= 2.70 day-1). Under the supply of CO2 enriched air to the inorganic medium, specific growth rate of 3.30 day was obtained at more than 0.6% CO2 concentration. Although the isolate showed a little growth in 0.5% peptone medium, it grew promptly when it was incubated in association with B. megaterium. This symbiotical growth took place under light and oxygen limited conditions (μ=4.50 day-1, 2°C). No growth of Chlorella sp. was observed under an aerobic condition. Growth rate of the isolate was accelerated with an increase of temperature and reached to the maximum μ of 8.0 day-1 at 36°C. Rapid growth was still observed at 42°C. But, this high growth rate continued only for 12 hrs. In 0.1% glycine medium, the maximum growth rate without bacteria was observed at 30°C., and growth was completely ceased above 40°C. Carbon analysis before and after incubation indicated that organic carbon degraded by the bacterium quantitatively transferred to the biomass. This symbiotical growth was also observed in simple organic medium in which B. megaterium could grow. From these results, it was assumed that the symbiosis observed between B. megaterium and Chlorella sp. fundamentaly consisted of interchange of CO2 and O2. But, high growth rate observed in symbiosis might indicate the existence of more complicated mechanisms supporting each other.

Automated Antibody Detection in a Low Ionic Strength (Glycine) Medium

Automated Antibody Detection in a Low Ionic Strength (Glycine) Medium