Carbohydrate metabolism in the Plasmodium of the myxomycete Physarum flavicomum

1973 ◽  
Vol 19 (7) ◽  
pp. 803-810 ◽  
Author(s):  
Thomas J. Lynch ◽  
Henry R. Henney Jr.
Keyword(s):  
Carbohydrate Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Inorganic Nitrogen ◽  
Adenosine Monophosphate ◽  
Pentose Phosphate ◽  
Inorganic Nitrogen Source ◽  
Defined Media ◽  
Pentose Phosphate Pathways ◽  
Citrate Phosphate ◽  
Stimulation Of

Carbohydrate metabolism in the growing plasmodial phase of Physarum flavicomum was studied in partially defined media using the radiorespirometric technique and specifically labeled 14C-substrates. The Embden–Meyerhof–Parnas (EMP) – tricarboxylic acid cycle (TCA) and the pentose phosphate pathways are the routes by which glucose is used by this myxomycete. The replacement of the usual citrate–phosphate buffer by succinate–phosphate results in a decreased uptake of 14C-glucose from the medium and a corresponding decline in the rate of interval 14CO2 evolution. The addition of an inorganic nitrogen source (ammonium nitrate) to the medium also decreases the rate of carbohydrate metabolism and alters the relative participation of the pathways by favoring the EMP–TCA. Supplementing the medium with cyclic-3′-5′-adenosine monophosphate produces a transient stimulation of the rate of metabolism by the EMP–TCA. The Plasmodium is relatively impermeable to gluconate and pyruvate and does not readily metabolize amino acids.

Carbohydrate metabolism in Acanthamoeba castellanii. 1. The activity of key enzymes and [14C]-glucose metabolism

1973 ◽  
Vol 19 (9) ◽  
pp. 1131-1136 ◽  
Author(s):  
Lansing M. Prescott ◽  
Harold E. Hoyme ◽  
Darlene Crockett ◽  
Elena Hui
Keyword(s):  
Carbohydrate Metabolism ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Fumarate Hydratase ◽  
Acanthamoeba Castellanii ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
Key Enzymes ◽  
Glyceraldehydephosphate Dehydrogenase

The specific activities of a number of the key enzymes involved in carbohydrate metabolism in Acanthamoeba castellanii (Neff clone I–12) have been determined. The following Embden–Meyerhof and pentose phosphate pathway enzymes were present: glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokinase, phosphofructokinase, hexose diphosphatase, aldolase, glyceraldehydephosphate dehydrogenase, pyruvate kinase, and pyruvate-phosphate dikinase. The following tricarboxylic acid cycle enzymes were also found: citrate synthase, aconitase, isocitrate dehydrogenase, succinate dehydrogenase, fumarate hydratase, and malate dehydrogenase. The degradation of glucose-U-14C to 14CO2 was examined. Aerobic 14CO2 production from glucose-U-14C was 3.4-fold greater than anaerobic production. The data provide further evidence that the Embden–Meyerhof, pentose phosphate, and tricarboxylic acid cycle pathways are probably functional in A. castellanii.

Roles of low pH, carbon and inorganic nitrogen source use in chlamydospore formation by Fusarium solani

1976 ◽  
Vol 22 (9) ◽  
pp. 1381-1389 ◽  
Author(s):  
Gary J. Griffin
Keyword(s):  
Fusarium Solani ◽  
Inorganic Nitrogen ◽  
Nitrogen Deficiency ◽  
Low Ph ◽  
Inorganic Nitrogen Source ◽  
Chlamydospore Formation ◽  
Sudan Iii ◽  
Source Use ◽  
Germ Tubes ◽  
Citrate Phosphate

Citrate and malate were poorer sources of exogenous carbon than several hexose, pentose, or disaccharide sugars for supporting macroconidial germination by Fusarium solani at high conidial density (1 × 105 conidia/ml). Only citrate, however, failed to block chlamydospore morphogenesis to a degree comparable to glucose or other readily used sugars. Mostly immature chlamydospores were formed in the presence of citrate. At low conidial density (5 × 103 conidia/ml), exogenous carbon-independent macroconidial germination and subsequent rapid chlamydospore formation on germ tubes was not inhibited by ammonium or nitrate nitrogen. The citrate–phosphate buffered, low pH (4.0) medium of Cochrane induced more immature chlamydospore formation by F. solani than a pH 6.0 medium, but few mature chlamydospores were formed in either medium. Condensation of hyphal cytoplasm into developing chlamydospores, a character typical of chlamydospore formation, did not occur extensively and macroconidia, hyphae, and immature chlamydospores stained deeply with Sudan III, suggesting lipid biosynthesis. This inhibition of chlamydospore maturation may be due partly to nitrogen deficiency imposed by the high C: N ratio of the medium and to the presence of citrate. Only vesiculate hyphal cells were formed by F. solani f. sp. phaseoli in both media.Field soils to which the clone of F. solani used is indigenous had mean pH values ranging from 5.2 to 6.0.

Stimulation of dextranase production by oxidized dextran

1970 ◽  
Vol 16 (9) ◽  
pp. 841-844 ◽  
Author(s):  
Robert G. Brown
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Enzyme Production ◽  
Inorganic Nitrogen ◽  
Penicillium Funiculosum ◽  
Inorganic Nitrogen Source ◽  
Oxidized Dextran ◽  
Excess Glucose ◽  
Stimulation Of

Penicillium funiculosum, Penicillium lilacinum, and Spicaria violacea produced excellent yields of dextranase if ketodextran replaced dextran as a carbon source. Ketodextrans I and II having degrees of substitution of 2 and 20% respectively were used in this study. P. funiculosum grew equally well on dextran and ketodextran I but less well on ketodextran II. Addition of a readily metabolizable carbohydrate such as glucose, sucrose, or galactose stimulated growth on ketodextran II, resulting in better dextranase production. However, excess glucose reversed this increase in enzyme production. Replacement of an inorganic nitrogen source with an organic one further stimulated dextranase production during growth of P. funiculosum on ketodextran II.

Metabolism of glucose-14C, pyruvate-14C, and mannitol-14C by Melampsora lini. I. Uptake

1968 ◽  
Vol 46 (4) ◽  
pp. 435-440 ◽  
Author(s):  
P. G. Williams ◽  
Michael Shaw
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Rust Fungus ◽  
Aerial Mycelium ◽  
Dry Weight ◽  
Significant Negative Correlation ◽  
Mean Value ◽  
Pentose Phosphate ◽  
Endogenous Respiration ◽  
Melampsora Lini ◽  
Pentose Phosphate Pathways

Aerial mycelium of the flax rust fungus (Melampsora lini (Pers.) Lév.) was grown on infected flax cotyledons in tissue culture. The endogenous respiration of detached mycelium varied from 1.5 to 4.8 μl/h per milligram dry weight, with a mean value of 2.6 ± 1.0. There was a significant negative correlation between respiration rate and percentage dry weight (r = −0.832; P < 0.025). The respiration of mycelium stored for longer than 10 h after excision was stimulated by the addition of glucose; such stimulation was not obtained consistently with freshly collected mycelium.The production of 14CO2 and the disappearance of radioactivity from the medium were measured at intervals during incubation of mycelium with glucose-1- and -6-14C, sodium pyruvate-1-, -2-, and -3-14C and mannitol-1-6-14C. Evidence was obtained that glucose is oxidized in the Embden–Meyerhof and pentose phosphate pathways and that pyruvate is oxidized via acetyl CoA and the tricarboxylic acid cycle. Rapid utilization of pyruvate- and mannitol-14C was preceded by a lag period of 4 to 9 h. The results are discussed in relation to the suitability of aerial mycelium for the study of rust metabolism.

scholarly journals Enzymes of the intermediary carbohydrate metabolism of Polyangium cellulosum

1985 ◽  
Vol 31 (12) ◽  
pp. 1142-1146 ◽  
Author(s):  
Renu Sarao ◽  
Howard D. McCurdy ◽  
Luciano Passador
Keyword(s):  
Carbohydrate Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Fold Increase ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
The Family ◽  
The Glyoxylate Cycle ◽  
Pentose Phosphate Shunt

Crude extracts of vegetative cells of the cellulolytic myxobacter Polyangium cellulosum contained significant levels of the enzymes of the tricarboxylic acid cycle and the glyoxylate cycle. Key enzymes of glycolysis and the pentose phosphate shunt were also detected. Specific activities of hexokinase and fructose- 1,6-diphosphate aldolase exhibited a 10-fold increase when the cells were grown in complex medium containing glucose. Cytochromes of a, b, and c type were demonstrated. By the use of a dispersly growing strain of P. cellulosum, its generation time was determined to be 22–24 h. This study suggests that the organism probably uses glycolysis and citric acid cycle for complete oxidation of glucose. The exact role of the glyoxylate cycle and pentose phosphate shunt cannot be deduced from this study. This is the first report on the study of intermediary carbohydrate metabolism in any member of the family Polyangiaceae.

scholarly journals Complete Genome Sequence of the Marine, Chemolithoautotrophic, Ammonia-Oxidizing Bacterium Nitrosococcus oceani ATCC 19707

2006 ◽  
Vol 72 (9) ◽  
pp. 6299-6315 ◽  
Author(s):  
Martin G. Klotz ◽  
Daniel J. Arp ◽  
Patrick S. G. Chain ◽  
Amal F. El-Sheikh ◽  
Loren J. Hauser ◽  
...  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Reducing Power ◽  
Pentose Phosphate ◽  
Type I ◽  
Circular Chromosome ◽  
Bisphosphate Carboxylase ◽  
Terminal Electron Acceptor ◽  
Genes Encoding ◽  
Pentose Phosphate Pathways ◽  
Ammonia Oxidizing Bacterium

ABSTRACT The gammaproteobacterium Nitrosococcus oceani (ATCC 19707) is a gram-negative obligate chemolithoautotroph capable of extracting energy and reducing power from the oxidation of ammonia to nitrite. Sequencing and annotation of the genome revealed a single circular chromosome (3,481,691 bp; G+C content of 50.4%) and a plasmid (40,420 bp) that contain 3,052 and 41 candidate protein-encoding genes, respectively. The genes encoding proteins necessary for the function of known modes of lithotrophy and autotrophy were identified. Contrary to betaproteobacterial nitrifier genomes, the N. oceani genome contained two complete rrn operons. In contrast, only one copy of the genes needed to synthesize functional ammonia monooxygenase and hydroxylamine oxidoreductase, as well as the proteins that relay the extracted electrons to a terminal electron acceptor, were identified. The N. oceani genome contained genes for 13 complete two-component systems. The genome also contained all the genes needed to reconstruct complete central pathways, the tricarboxylic acid cycle, and the Embden-Meyerhof-Parnass and pentose phosphate pathways. The N. oceani genome contains the genes required to store and utilize energy from glycogen inclusion bodies and sucrose. Polyphosphate and pyrophosphate appear to be integrated in this bacterium's energy metabolism, stress tolerance, and ability to assimilate carbon via gluconeogenesis. One set of genes for type I ribulose-1,5-bisphosphate carboxylase/oxygenase was identified, while genes necessary for methanotrophy and for carboxysome formation were not identified. The N. oceani genome contains two copies each of the genes or operons necessary to assemble functional complexes I and IV as well as ATP synthase (one H+-dependent F0F1 type, one Na+-dependent V type).

scholarly journals Malonyl-proteome profiles of Staphylococcus aureus reveal lysine malonylation modification in enzymes involved in energy metabolism

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yanan Shi ◽  
Jingjing Zhu ◽  
Yan Xu ◽  
Xiaozhao Tang ◽  
Zushun Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Energy Metabolism ◽  
Active Sites ◽  
Current Knowledge ◽  
Tricarboxylic Acid Cycle ◽  
Protein A ◽  
Pentose Phosphate ◽  
Post Translational Modification ◽  
Bacterial Physiology ◽  
Dihydrolipoyl Dehydrogenase

Abstract Background Protein lysine malonylation, a novel post-translational modification (PTM), has been recently linked with energy metabolism in bacteria. Staphylococcus aureus is the third most important foodborne pathogen worldwide. Nonetheless, substrates and biological roles of malonylation are still poorly understood in this pathogen. Results Using anti-malonyl-lysine antibody enrichment and high-resolution LC-MS/MS analysis, 440 lysine-malonylated sites were identified in 281 proteins of S. aureus strain. The frequency of valine in position − 1 and alanine at + 2 and + 4 positions was high. KEGG pathway analysis showed that six categories were highly enriched, including ribosome, glycolysis/gluconeogenesis, pentose phosphate pathway (PPP), tricarboxylic acid cycle (TCA), valine, leucine, isoleucine degradation, and aminoacyl-tRNA biosynthesis. In total, 31 malonylated sites in S. aureus shared homology with lysine-malonylated sites previously identified in E. coli, indicating malonylated proteins are highly conserved among bacteria. Key rate-limiting enzymes in central carbon metabolic pathways were also found to be malonylated in S. aureus, namely pyruvate kinase (PYK), 6-phosphofructokinase, phosphoglycerate kinase, dihydrolipoyl dehydrogenase, and F1F0-ATP synthase. Notably, malonylation sites were found at or near protein active sites, including KH domain protein, thioredoxin, alanine dehydrogenase (ALD), dihydrolipoyl dehydrogenase (LpdA), pyruvate oxidase CidC, and catabolite control protein A (CcpA), thus suggesting that lysine malonylation may affect the activity of such enzymes. Conclusions Data presented herein expand the current knowledge on lysine malonylation in prokaryotes and indicate the potential roles of protein malonylation in bacterial physiology and metabolism.

scholarly journals Novel Antarctic yeast adapts to cold by switching energy metabolism and increasing small RNA synthesis

2021 ◽  
Author(s):  
D. Touchette ◽  
I. Altshuler ◽  
C. Gostinčar ◽  
P. Zalar ◽  
I. Raymond-Bouchard ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ethanol Fermentation ◽  
Phylogenetic Analyses ◽  
Regulation Of Gene Expression ◽  
Pentose Phosphate ◽  
Metabolic Switch ◽  
Antarctic Yeast ◽  
Fungal Adaptation ◽  
Pentose Phosphate Pathways ◽  
Post Transcriptional Regulation

AbstractThe novel extremophilic yeast Rhodotorula frigidialcoholis, formerly R. JG1b, was isolated from ice-cemented permafrost in University Valley (Antarctic), one of coldest and driest environments on Earth. Phenotypic and phylogenetic analyses classified R. frigidialcoholis as a novel species. To characterize its cold-adaptive strategies, we performed mRNA and sRNA transcriptomic analyses, phenotypic profiling, and assessed ethanol production at 0 and 23 °C. Downregulation of the ETC and citrate cycle genes, overexpression of fermentation and pentose phosphate pathways genes, growth without reduction of tetrazolium dye, and our discovery of ethanol production at 0 °C indicate that R. frigidialcoholis induces a metabolic switch from respiration to ethanol fermentation as adaptation in Antarctic permafrost. This is the first report of microbial ethanol fermentation utilized as the major energy pathway in response to cold and the coldest temperature reported for natural ethanol production. R. frigidialcoholis increased its diversity and abundance of sRNAs when grown at 0 versus 23 °C. This was consistent with increase in transcription of Dicer, a key protein for sRNA processing. Our results strongly imply that post-transcriptional regulation of gene expression and mRNA silencing may be a novel evolutionary fungal adaptation in the cryosphere.

scholarly journals Metabolome Shift in Both Metastatic Breast Cancer Cells and Astrocytes Which May Contribute to the Tumor Microenvironment

2021 ◽  
Vol 22 (14) ◽  
pp. 7430
Author(s):  
Hiromi Sato ◽  
Ayaka Shimizu ◽  
Toya Okawa ◽  
Miaki Uzu ◽  
Momoko Goto ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Metastatic Breast ◽  
Principal Component ◽  
Pentose Phosphate ◽  
Metastatic Brain Tumors ◽  
Pentose Phosphate Pathways ◽  
Culture Supernatants

The role of astrocytes in the periphery of metastatic brain tumors is unclear. Since astrocytes regulate central nervous metabolism, we hypothesized that changes in astrocytes induced by contact with cancer cells would appear in the metabolome of both cells and contribute to malignant transformation. Coculture of astrocytes with breast cancer cell supernatants altered glutamate (Glu)-centered arginine–proline metabolism. Similarly, the metabolome of cancer cells was also altered by astrocyte culture supernatants, and the changes were further amplified in astrocytes exposed to Glu. Inhibition of Glu uptake in astrocytes reduces the variability in cancer cells. Principal component analysis of the cancer cells revealed that all these changes were in the first principal component (PC1) axis, where the responsible metabolites were involved in the metabolism of the arginine–proline, pyrimidine, and pentose phosphate pathways. The contribution of these changes to the tumor microenvironment needs to be further pursued.

Tillage and Inorganic Nitrogen Source Effects on Nitrous Oxide Emissions from Irrigated Cropping Systems

2010 ◽  
Vol 74 (2) ◽  
pp. 436-445 ◽  
Author(s):  
Ardell D. Halvorson ◽  
Stephen J. Del Grosso ◽  
Francesco Alluvione
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Source ◽  
Cropping Systems ◽  
Inorganic Nitrogen ◽  
Nitrous Oxide Emissions ◽  
Inorganic Nitrogen Source ◽  
Source Effects
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