The metabolic network in the yeast Saccharomyces cerevisiae was reconstructed using currently available genomic, biochemical, and physiological information. The metabolic reactions were compartmentalized between the cytosol and the mitochondria, and transport steps between the compartments and the environment were included. A total of 708 structural open reading frames (ORFs) were accounted for in the reconstructed network, corresponding to 1035 metabolic reactions. Further, 140 reactions were included on the basis of biochemical evidence resulting in a genome-scale reconstructed metabolic network containing 1175 metabolic reactions and 584 metabolites. The number of gene functions included in the reconstructed network corresponds to approximately 16% of all characterized ORFs in S. cerevisiae. Using the reconstructed network, the metabolic capabilities of S. cerevisiae were calculated and compared with Escherichia coli. The reconstructed metabolic network is the first comprehensive network for a eukaryotic organism, and it may be used as the basis for in silico analysis of phenotypic functions.

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Genome-Scale Reconstruction of the Saccharomyces cerevisiae Metabolic Network

Fatty acid and lipid composition of 10 species of microalgae used in mariculture

https://deepblue.lib.umich.edu/bitstream/2027.42/30145/1/0000522.pdf

Cardiolipins and biomembrane function

Oleaginous yeasts for biodiesel: current and future trends in biology and production.

Publisher Summary This chapter describes the flame ionization detection (FID) applied to thin-layer chromatography (TLC) on coated quartz rods. Iatroscan combines TLC with the FID, and the TLC/FID combination extends TLC sensitivity by two or more orders of magnitude into the range achieved only with gas chromatography. A Chromarod, after development and freeing of solvent, is passed through the hydrogen flame and the carbon ions produced are collected and amplified. In the actual apparatus the housing supports a moving frame, which in the TH-10 model that accepts any number of Chromarods up to 10. The short development time of the Chromarod-S is an encouragement to the sequential use of different solvent systems. By judicious choice of solvent systems, complex separations can often be effected that are not possible with one solvent system, and others can be much improved. A complex mixture of hydrocarbon in a heavy fuel oil could be resolved on a Chromarod-S into four main fractions, which includes asphaltines and polar compounds, resins, polynuclear aromatics and alkyl aromatics, and aliphatics.

Flame ionization detection applied to thin-layer chromatography on coated quartz rods.

The detailed composition of cellular lipid of more than 23 species of yeast has been determined quantitatively by thinchrography on quartz rods, a method previously used for estimating cellular lipids of seven species of yeast. That data was fortified by neutral and phospholipid quantitations on 30 species of yeast cells. Most of the test organisms contained 7-15% total lipid and 3-6% total phospholipid per dry cell weight, except for the extremely high accumulation of triglycerides in two species of Lipomyces. Qualitatively, 30 species of yeast cells contained similar neutral lipid constituents (triglyceride, sterol ester, free fatty acid, and free sterol) and polar lipid components (phosphatidyl choline, phosphatidyl ehtanolamine, phosphatidyl serine, phosphatidyl inositol, cardiolipin, and ceramide monohexoside) without minor constituents. Based on the quantitative composition of neutral lipids, the 30 species of yeast were divided into two groups , the triglyceride predominant group and the sterol derivative group. These groupings were fairly well overlapped from the standpoint of the distribution characteristics of fatty acid. The relative polar lipid compositions also grossly resembled each other. Only one exception of polar lipid composition in yeast cells was found in Rhodotorula rubra species which contained phosphatidyl ethanolamine as the most abundant phospholipid. Fatty acid distribution patterns in yeast cells consistently coincided with other reports concerning fatty acid composition of yeast cells. Correlation of lipid composition and classification of yeasts are suggested and discussed.

Lipid composition of 30 species of yeast.

Partial glyceride mixtures, which include 1-monoglyceride, 2-monoglyceride, free fatty acid, 1,2-diglyceride, 1,3-diglyceride and triglyceride, could be separated from each other on a 3% boric-acid-impregnated Chromarod S-II (silica gel sintered quartz rod) with either chloroform/acetone (96∶4, v/v) or chloroform/acetone/acetic acid (100∶1∶1, v/v) as the developing solvent mixtures. The components separated on the boric-acid-impregnated rod were automatically quantitated in a hydrogen flame ionization detector (Iatroscan). The relative responses of 1,2-diglyceride, 1,3-diglyceride, free fatty acid and triglyceride were slightly lower than theoretical responses based on weight percentage, whereas 1-monoglyceride and 2-monoglyceride showed slightly higher responses. These responses were converged within a maximal error of 5–10% (SD). Boric-acid-impregnated rods could be used repeatedly, ca. 5 times without any reconditioning procedure.

Quantitative determination of isomeric glycerides, free fatty acids and triglycerides by thin layer chromatography-flame ionization detector system.

Application of a thin-layer chromatography—flame-ionization detection system for the determination of complex lipid constituents

Responses of sterol, fatty acid, sterol ester and triglyceride on a quantitative thin layer chrornato-graphic apparatus which was equipped with a flame ionization detector were determined using with six kinds of neutral lipid mixtures. These responses were represented as relative responses against to tri-glyceride response and converged within maximum error of 5-10% (S.D.) over a range of loads (2-10 μg lipid). All of the relative responses were in proportion to the weight ratio. It was found that the method is very superior and convenient means for the quantitative estimation of neutral lipid compositions.

Quantitative Determination of Neutral Lipids on Thin Layer-FID Chromatography

The merits and disadvantages of using the silica gel-sintered plate for lipid chromatographic analysis were investigated in detail. The commercially available sintered plate could be used repeatedly, employing the reconditioning procedure which involved chromic-sulfuric acid treatment and subsequent activation. The reconditioned sintered plate has now been used successfully 20 times, for lipid analysis without any deterioration of the excellent resolution power for complex lipid mixtures for all the solvent systems. Since the sintered plate is sturdy, the chromatogplate could be immersed directly in the liquid reaction mixture, so that spots on the chromatogram could be seen and impregnated plates prepared simply. The sintered plate was found to be much more economical than the silica gel-coated plate.

Masamichi Tanaka

Papers

Lipid composition of 30 species of yeast.

Quantitative determination of isomeric glycerides, free fatty acids and triglycerides by thin layer chromatography-flame ionization detector system.

Application of a thin-layer chromatography—flame-ionization detection system for the determination of complex lipid constituents

Quantitative Determination of Neutral Lipids on Thin Layer-FID Chromatography

Application of silica gel-sintered plate to thin layer lipid chromatographic analysis.