Investigation by NMR of metabolic routes to bacterial γ-poly(glutamic acid) using 13C-labeled citrate and glutamate as media carbon sources

1995 ◽  
Vol 41 (10) ◽  
pp. 902-909 ◽  
Author(s):  
Anne-Marie Cromwick ◽  
Richard A. Gross

Bacillus licheniformis ATCC 9945A produces γ-poly(glutamic acid) (γ-PGA) when using glutamate, citrate, and glycerol in combination as media carbon sources. Also, various aspects of B. licheniformis cellular physiology are affected by the concentration of Mn(II) salts in culture media. Thus, the metabolism of carbon sources into γ-PGA as a function of MnSO4 concentration was studied by enriching the media with either L-[1,2-13C]glutamic acid (NH2—2CH(1COOH)—(CH2)2-COOH) or [1,5-13C]citric acid (HOO1C—CH2—C(OH)(COOH)—CH2—5COOH) at two media MnSO4 concentrations (615 and 0 μM). Enrichment factors (EF) from 13C-NMR spectra were calculated from the ratio of peak intensities from 13C-enriched γ-PGA divided by the ratio of peak intensities for nonenriched γ-PGA. EF values were than used to determine the percentage of repeat units that were formed from glutamate and citrate. The percentage of repeat units formed from provided glutamate at the 0 and 615 μM Mn(II) media concentrations was 89 ± 14 and 67 ± 11%, respectively. These respective products have 51 ± 9 and 39 ± 11% of their repeat units formed with apparent retention of the glutamate carbon skeleton. Also, enrichment of γ-PGA repeat units at C-1 was found to be lower than C-2 at both Mn(II) levels. Thus, provided glutamate was used to a large extent for polymer formation with both retention of the carbon skeleton as well as decarboxylation at C-1. Provided citrate was also used as a source of carbon to form repeat units. At the 0 and 615 μM media Mn(II) levels, 9 ± 4 and 19 ± 5% of repeat units were formed from citrate. It is believed that citrate is metabolized to γ-PGA by entry into the citric acid cycle and formation of α-ketoglutarate. Analysis of products from cultivations where both glutamate and citrate were 13C enriched indicated that citrate and glutamate carbon source metabolism to γ-PGA occurs via independent pathways to common monomer precursors without multiple recycling of these carbon sources through catabolic and anabolic pathways.Key words: γ-poly(glutamic acid), metabolism, manganese, Bacillus licheniformis, nuclear magnetic resonance.

1957 ◽  
Vol 35 (6) ◽  
pp. 365-371 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Glutamic acid, aspartic acid, and threonine isolated from the gluten of wheat plants to which acetate-1-C14 or -2-C14 was administered during growth have been degraded to determine the complete intramolecular distribution of C14. Sixty-three per cent of the activity in glutamic acid arising from acetate-1-C14 was in carbon-5 and 20% in carbon-1; glutamic acid from acetate-2-C14 contained 43% of the activity in carbon-4 and about 18% in each of carbons 2 and 3. Acetate-1-C14 resulted in labelling largely in the terminal carbons of aspartic acid, and acetate-2-C14 preferentially labelled the internal carbons. The results show that the Krebs' citric acid cycle provides a major pathway for the biosynthesis of the dicarboxylic amino acids of wheat gluten.Striking parallelism in the intramolecular distribution of carbon-14 in aspartic acid and threonine demonstrates that these amino acids are closely linked biosynthetically and is in accord with the idea that aspartic acid provides the carbon skeleton for threonine.


1975 ◽  
Vol 53 (2) ◽  
pp. 144-155 ◽  
Author(s):  
Gaëtan Harvais ◽  
Ain Raitsakas

A fungus (Rs10) symbiotic with orchids was grown in axenic liquid-still culture on mineral–sugar media. Dextrose was limiting at 1% and 2%, with mycelium dry weights directly proportional to the amount of sugar in the medium, but not at 3%. Sucrose gave similar results and was converted into reducing sugars, in the medium, in excess of utilization. With 3% sugar growth was not much better than with 2%, and daily dry weight values were more variable after the active growth phase. With 1% and 2% dextrose in the media, and 10, 20, and 30 ml/flask, dry weight was not affected by the different aeration conditions. Inocula failed to grow on media with pH 3.0, but growth seemed normal with pH 4.5. Ninhydrin-positive substances were not released in the culture media but were found in ethanol extracts of the mycelium. They were more abundant during the active growth phase and on media with 1% vs. 2% dextrose; with less sugar, high levels were maintained for longer periods. They consisted mainly of glutamic acid, glutamine, and aspartic acid, with some fluctuations in concentration related to growth phase. Metabolism seemed different on media with ammonium + nitrate vs. nitrate alone as nitrogen source. The hyphal wall contained chitin.Protocorms of Dactylorhiza purpurella (an orchid with which Rs10 is symbiotic) were grown on eight nutrient media with one amino acid in each, until only the latter were depleted. The best results were with glutamic acid, ornithine, and arginine, followed by aspartic acid and glycine. Alanine, serine, and lysine were toxic. N-acetyl-D-glucosamine derived from chitin was drip-fed to other cultures. It was ineffective at low and toxic at high concentrations.Implications of the results relating to mycorrhizal associations are briefly discussed.


1957 ◽  
Vol 35 (1) ◽  
pp. 365-371 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Glutamic acid, aspartic acid, and threonine isolated from the gluten of wheat plants to which acetate-1-C14 or -2-C14 was administered during growth have been degraded to determine the complete intramolecular distribution of C14. Sixty-three per cent of the activity in glutamic acid arising from acetate-1-C14 was in carbon-5 and 20% in carbon-1; glutamic acid from acetate-2-C14 contained 43% of the activity in carbon-4 and about 18% in each of carbons 2 and 3. Acetate-1-C14 resulted in labelling largely in the terminal carbons of aspartic acid, and acetate-2-C14 preferentially labelled the internal carbons. The results show that the Krebs' citric acid cycle provides a major pathway for the biosynthesis of the dicarboxylic amino acids of wheat gluten.Striking parallelism in the intramolecular distribution of carbon-14 in aspartic acid and threonine demonstrates that these amino acids are closely linked biosynthetically and is in accord with the idea that aspartic acid provides the carbon skeleton for threonine.


2017 ◽  
Vol 6 (8) ◽  
pp. 5459
Author(s):  
Chandra Teja K. ◽  
Rahman S. J.

Entomopathogenic fungi like Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii are used in biological control of agricultural insect pests. Their specific mode of action makes them an effective alternative to the chemical Insecticides. Virulent strains of Entomopathogenic fungi are effectively formulated and used as bio-insecticides world-wide. Amenable and economical multiplication of a virulent strain in a large scale is important for them to be useful in the field. Culture media plays a major role in the large-scale multiplication of virulent strains of Entomopathogens. Different substrates and media components are being used for this purpose. Yet, each strain differs in its nutritional requirements for the maximum growth and hence it is necessary to standardize the right components and their optimum concentrations in the culture media for a given strain of Entomopathogen. In the current study, three different nitrogen sources and two different carbon sources were tried to standardize the mass multiplication media for seven test isolates of Entomopathogenic fungi. A study was also conducted to determine the ideal grain media for the optimum conidial yields of the test isolates. Yeast extract was found to be the best Nitrogen source for the isolates. The isolates tested, differed in their nutritional requirements and showed variation in the best nitrogen and carbon sources necessary for their growth. Variation was also found in the optimum concentration of both the ingredients for the growth and sporulation of the isolates. In the solid-state fermentation study, rice was found to be the best grain for the growth of most of the fungi followed by barley. The significance of such a study in the development of an effective Myco-insecticide is vital and can be successfully employed in agriculture is discussed.


2021 ◽  
Vol 9 (3) ◽  
pp. 533
Author(s):  
Alex Graça Contato ◽  
Tássio Brito de Oliveira ◽  
Guilherme Mauro Aranha ◽  
Emanuelle Neiverth de Freitas ◽  
Ana Claudia Vici ◽  
...  

The lignocellulosic biomass comprises three main components: cellulose, hemicellulose, and lignin. Degradation and conversion of these three components are attractive to biotechnology. This study aimed to prospect fungal lignocellulolytic enzymes with potential industrial applications, produced through a temporal analysis using Hymenaea courbaril and Tamarindus indica seeds as carbon sources. α-L-arabinofuranosidase, acetyl xylan esterase, endo-1,5-α-L-arabinanase, β-D-galactosidase, β-D-glucosidase, β-glucanase, β-D-xylosidase, cellobiohydrolase, endoglucanase, lichenase, mannanase, polygalacturonase, endo-1,4-β-xylanase, and xyloglucanase activities were determined. The enzymes were produced for eight filamentous fungi: Aspergillus fumigatus, Trametes hirsuta, Lasiodiplodia sp., two strains of Trichoderma longibrachiatum, Neocosmospora perseae, Fusarium sp. and Thermothelomyces thermophilus. The best producers concerning enzymatic activity were T. thermophilus and T. longibrachiatum. The optimal conditions for enzyme production were the media supplemented with tamarind seeds, under agitation, for 72 h. This analysis was essential to demonstrate that cultivation conditions, static and under agitation, exert strong influences on the production of several enzymes produced by different fungi. The kind of sugarcane, pretreatment used, microorganisms, and carbon sources proved limiting sugar profile factors.


2007 ◽  
Vol 7 ◽  
pp. 525-532
Author(s):  
Qing Guo ◽  
Zao-he Wu ◽  
Ming-liang Qian ◽  
Binhe Gu

The purpose of this study was to investigate the roles of coral sands in the enrichment and isolation of ammonium-oxidizing bacteria (AOB). We hypothesized that the porous coral sands provided additional surface area and nutrients for the growth of periphytic AOB. In the present study, an orthogonal test was designed to compare the AOB conversion rates of ammonium-nitrogen (NH4+N) to nitrite-nitrogen (NO2--N) among various combinations of culture media. Results showed that the conversion of NH4+N to NO2--N increased significantly when the coral sands were added, implying that coral sands were beneficial to the growth of AOB. Additions of potassium dihydrogen phosphate (KH2PO4) or sodium bicarbonate (NaHCO3) to the media became unnecessary when coral sands were used, but the addition of KH2PO4was needed when the molar nitrogen to phosphorus (N:P) ratio reached 10 in the enrichment media using calcium carbonate (CaCO3) powder as a calcium source.


Author(s):  
Gabriela de Oliveira Fernandes ◽  
Marcella Pecora Milazzotto ◽  
Andrei Antonioni Guedes Fidelis ◽  
Taynan Stonoga Kawamoto ◽  
Ligiane de Oliveira Leme ◽  
...  

Abstract The present study aimed to identify biomarkers to assess the quality of in vitro produced (IVP) bovine embryos in the culture media. IVP embryos on Day (D) 5 of development were transferred to individual drops, where they were maintained for the last 48 h of culture. Thereafter, the medium was collected and the embryos were transferred to the recipients. After pregnancy diagnosis, the media were grouped into the pregnant and nonpregnant groups. The metabolic profiles of the media were analyzed via electrospray ionization mass spectrometry, and the concentrations of pyruvate, lactate, and glutamate were assessed using fluorimetry. The spectrometric profile revealed that the media from embryos from the pregnant group presented a higher signal intensity compared to that of the nonpregnant group; the ions 156.13 Da [M + H]+, 444.33 Da [M + H]+, and 305.97 Da [M + H]+ were identified as biomarkers. Spent culture medium from expanded blastocysts (Bx) that established pregnancy had a greater concentration of pyruvate (p = 0.0174) and lesser concentration of lactate (p = 0.042) than spent culture medium from Bx that did not establish pregnancy. Moreover, pyruvate in the culture media of Bx can predict pregnancy with 90.9% sensitivity and 75% specificity. In conclusion, we identified markers in the culture media that helped in assessing the most viable IVP embryos with a greater potential to establish pregnancy.


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