Carbohydrate metabolism and gluconic acid synthesis by Botrytis cinerea

1989 ◽  
Vol 67 (10) ◽  
pp. 2888-2893 ◽  
Author(s):  
Bernard Donèche

The pathways of glucose catabolism were examined in a B. cinerea strain isolated from grape. Respirometric and enzymatic studies indicated that this plant parasite catabolized glucose through the Embden–Meyerhof and hexose monophosphate shunt pathways. Data also suggested functioning of an active tricarboxylic acid cycle and presence of the glyoxylate cycle. Direct oxidation of glucose by means of glucose oxidase led to gluconic acid accumulation in the medium during the stationary phase of growth. Part of the glucose oxidase was extracellular and could have technological consequences in wine making.


2014 ◽  
Vol 63 (4) ◽  
pp. 1009-1016 ◽  
Author(s):  
N. A. Samoilova ◽  
M. A. Krayukhina ◽  
T. P. Klimova ◽  
T. A. Babushkina ◽  
O. V. Vyshivannaya ◽  
...  


1959 ◽  
Vol 5 (1) ◽  
pp. 1-8 ◽  
Author(s):  
N. B. Madsen ◽  
R. M. Hochster

Cell-free extracts of Xanthomonas phaseoli contain the individual enzymes of the tricarboxylic acid cycle, and it is suggested that this is the main pathway for the terminal oxidation of carbohydrate in this organism. X. phaseoli can grow on a medium containing acetate as the sole source of carbon. Cell-free extracts of such acetate-grown organisms contain the enzymes of the glyoxylate cycle, and it is concluded that the operation of this cycle permits the initial stages of synthesis of complex cell material from acetate at a rate sufficiently high to account for the observed rate of growth on the acetate medium. The two enzymes required to modify a tricarboxylic acid cycle into a glyoxylate cycle are present in very small amounts (malate synthetase) or absent entirely (isocitritase) in extracts of glucose-grown X. phaseoli.



2021 ◽  
Vol 12 ◽  
Author(s):  
Yanqiang Ding ◽  
Zhuolin Yi ◽  
Yang Fang ◽  
Sulan He ◽  
Yuming Li ◽  
...  

Phosphate-solubilizing bacteria (PSB) can alleviate available phosphorus (AP)-deficiency without causing environmental pollution like chemical phosphate fertilizers. However, the research and application of PSB on the barren rocky soil is very rare. We screened six PSB from sweetpotato rhizosphere rocky soil. Among them, Ochrobactrum haematophilum FP12 showed the highest P-solubilizing ability of 1,085.00 mg/L at 7 days, which was higher than that of the most reported PSB. The assembled genome of PSB FP12 was 4.92 Mb with P-solubilizing and plant growth-promoting genes. In an AP-deficient environment, according to transcriptome and metabolomics analysis, PSB FP12 upregulated genes involved in gluconic acid synthesis and the tricarboxylic acid cycle, and increased the concentration of gluconic acid and malic acid, which would result in the enhanced P-solubilizing ability. Moreover, a series of experiments in the laboratory and field confirmed the efficient role of the screened PSB on significantly increasing AP in the barren rocky soil and promoting sweetpotato yield. So, in this study, we screened highly efficient PSB, especially suitable for the barren rocky soil, and explored the P-solubilizing mechanism. The research will reduce the demand for chemical phosphate fertilizers and promote the environment-friendly agricultural development.



Author(s):  
Shu Moriyama ◽  
Kazuya Nishio ◽  
Tsunehiro Mizushima

Malate dehydrogenase (MDH), a carbohydrate and energy metabolism enzyme in eukaryotes, catalyzes the interconversion of malate to oxaloacetate (OAA) in conjunction with that of nicotinamide adenine dinucleotide (NAD+) to NADH. Three isozymes of MDH have been reported in Saccharomyces cerevisiae: MDH1, MDH2 and MDH3. MDH1 is a mitochondrial enzyme and a member of the tricarboxylic acid cycle, whereas MDH2 is a cytosolic enzyme that functions in the glyoxylate cycle. MDH3 is a glyoxysomal enzyme that is involved in the reoxidation of NADH, which is produced during fatty-acid β-oxidation. The affinity of MDH3 for OAA is lower than those of MDH1 and MDH2. Here, the crystal structures of yeast apo MDH3, the MDH3–NAD+ complex and the MDH3–NAD+–OAA ternary complex were determined. The structure of the ternary complex suggests that the active-site loop is in the open conformation, differing from the closed conformations in mitochondrial and cytosolic malate dehydrogenases.



1966 ◽  
Vol 12 (5) ◽  
pp. 1015-1022 ◽  
Author(s):  
Margaret von Tigerstrom ◽  
J. J. R. Campbell

The enzymes of the glyoxylate cycle, the tricarboxylic acid cycle, glucose oxidation, and hydrogen transport were measured in extracts of Pseudomonas aeruginosa grown with glucose, α-ketoglutarate, or acetate as sole carbon source. The specific activity of isocitritase was increased 25-fold by growth on acetate whereas malate synthetase was increased only 4-fold. All of the enzymes of glucose metabolism, operative at the hexose level, were inducible. The enzymes of the tricarboxylic acid cycle were present under all conditions of growth but extracts from acetate-grown cells contained only one-quarter of the fumarase and pyruvic oxidase activity and half the malate-oxidizing activity of the other extracts. Transhydrogenase, NADH oxidase, and NADPH oxidase activities were similar in each type of extracts. Most of the enzymes were present in the soluble cytoplasm, exceptions being glucose oxidase, succinic dehydrogenase, and NADH oxidase.



1989 ◽  
Vol 67 (2) ◽  
pp. 447-450 ◽  
Author(s):  
B. Dehorter ◽  
L. Lacoste

The activity of two enzymes of the tricarboxylic acid cycle (NADP+-isocitrate dehydrogenase, EC 1.1.1.42) and the glyoxylate cycle (isocitrate lyase, EC 4.1.3.1) were assayed in vitro to determine the effects of darkness, light, and mycosporin (P310) on sexual morphogenesis in Nectria galligena Bres. In the absence of mycosporin, high isocitrate lyase activity was associated with vegetative growth of fungi kept in the dark. In contrast, light-induced perithecial development and mycosporin biosynthesis could be correlated with high ratios of isocitrate dehydrogenase to isocitrate lyase activity. This was confirmed by the fact that when mycosporin was added to the nutrient medium with incubation in darkness, the fertility of the fungus was partially expressed and the activity of isocitrate lyase was significantly reduced. Thus this enzyme would be repressed in vivo by mycosporin. Because of its photomimetic role in sexual differentiation and regulation of intermediate metabolism, mycosporin appears to be a biochemical transmitter of light energy required for the formation of ascocarps.



1992 ◽  
Vol 70 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Koji Iwase

During mycelial culture of Tricholoma robustum, the medium gradually became acidified to approximately pH 3.9. High performance liquid chromatography showed that gluconic acid was secreted into the culture medium, and the amount of gluconic acid produced was measured by enzymatic analysis. Gluconic acid synthesis by all other related species, Tricholoma matsutake, Tricholoma caligatum, Tricholoma ponderosum, Tricholoma fulvocastaneum, and Tricholoma zelleri was poor, except for Tricholoma bakamatsutake, which showed relatively high productivity. Activity of glucose oxidase, which is responsible for gluconic acid production, was highest in T. robustum and second highest in T. bakamatsutake. The activity in these two species was much higher than those of other species. These results indicate that gluconic acid was synthesized from glucose by glucose oxidase in T. robustum as well as in T. bakamatsutake. Key words: ectomycorrhizal fungi, gluconic acid, glucose oxidase, Tricholoma robustum.



2007 ◽  
Vol 97 (3) ◽  
pp. 384-390 ◽  
Author(s):  
Yoav Hadas ◽  
Israel Goldberg ◽  
Ophry Pines ◽  
Dov Prusky

The contribution of gluconic acid secretion to the colonization of apple tissue by Penicillium expansum was analyzed by modulation (increase or decrease) of gluconic acid accumulation at the infection court. P. expansum isolates that express the most gox2 transcripts and concomitant glucose oxidase (GOX) activity and that secrete the most gluconic acid cause disease of apple at the fastest rate. Cultures grown under reduced oxygen concentration generated fewer gox2 transcripts, produced less gluconic acid, and led to a 15% reduction in disease. Furthermore, the detection of significantly high levels of transcripts of gox2 and GOX activity at the edge of the decaying tissue emphasize the involvement of GOX in tissue acidification of the decaying tissue. Taken together, these results emphasize the importance of GOX in the production of the gluconic acid that leads, in turn, to host tissue acidification. This acidification enhanced the expression of pectolytic enzymes and the establishment of conditions for necrotrophic development of P. expansum.



2016 ◽  
Vol 181 (2) ◽  
pp. 526-535 ◽  
Author(s):  
Caixia Cui ◽  
Haibin Chen ◽  
Biqiang Chen ◽  
Tianwei Tan


1999 ◽  
Vol 19 (10) ◽  
pp. 6720-6728 ◽  
Author(s):  
Zhengchang Liu ◽  
Ronald A. Butow

ABSTRACT The Hap2,3,4,5p transcription complex is required for expression of many mitochondrial proteins that function in electron transport and the tricarboxylic acid (TCA) cycle. We show that as the cells’ respiratory function is reduced or eliminated, the expression of four TCA cycle genes, CIT1, ACO1, IDH1, andIDH2, switches from HAP control to control by three genes, RTG1, RTG2, and RTG3. The expression of four additional TCA cycle genes downstream ofIDH1 and IDH2 is independent of theRTG genes. We have previously shown that theRTG genes control the retrograde pathway, defined as a change in the expression of a subset of nuclear genes, e.g., the glyoxylate cycle CIT2 gene, in response to changes in the functional state of mitochondria. We show that thecis-acting sequence controlling RTG-dependent expression of CIT1 includes an R box element, GTCAC, located 70 bp upstream of the Hap2,3,4,5p binding site in theCIT1 upstream activation sequence. The R box is a binding site for Rtg1p-Rtg3p, a heterodimeric, basic helix-loop-helix/leucine zipper transcription factor complex. We propose that in cells with compromised mitochondrial function, the RTG genes take control of the expression of genes leading to the synthesis of α-ketoglutarate to ensure that sufficient glutamate is available for biosynthetic processes and that increased flux of the glyoxylate cycle, via elevated CIT2 expression, provides a supply of metabolites entering the TCA cycle sufficient to support anabolic pathways. Glutamate is a potent repressor of RTG-dependent expression of genes encoding both mitochondrial and nonmitochondrial proteins, suggesting that it is a specific feedback regulator of the RTG system.



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