Glucose composition

EH13.15 Episomal expression of XYLl Glucose- limited fed-batch 47 g/L xylose 50 g/L glucose xylose, glucose (composition not given) 105.2 1.69 95 Lee et al. (2000)... 

The most familiar of all the carbohydrates is sucrose—common table sugar. Sucrose is a disacchar ide in which D-glucose and D-fructose are joined at then anomeric carbons by a glycosidic bond (Figure 25.7). Its chemical composition is the same ine-spective of its source sucrose from cane and sucrose from sugar beets are chemically identical. Because sucrose does not have a free anomeric hydroxyl group, it does not undergo mutarotation. 

The amino acid compositions and sequences of the /3-strands in porin proteins are novel. Polar and nonpolar residues alternate along the /3-strands, with polar residues facing the central pore or cavity of the barrel and nonpolar residues facing out from the barrel where they can interact with the hydrophobic lipid milieu of the membrane. The smallest diameter of the porin channel is about 5 A. Thus, a maltodextrin polymer (composed of two or more glucose units) must pass through the porin in an extended conformation (like a spaghetti strand). 

A medium is prepared having the following composition in tap water 1.0% glucose ... 

A small fermentation tank (5,000 parts by volume capacity) was charged with 3,000 parts by volume of a culture medium (pH 6.0) comprising 3% glucose, 1 % polypepton, 0.5% yeast extract and 0.5% malt extract. The medium was sterilized by heating in a conventional manner and cooled. This medium was inoculated with 150 parts by volume of a pre[Pg.1565]

Sterile agar slants are prepared using the Streptomyces sporulation medium of Hickey and Tresner, J. Bact., vol. 64, pages 891-892 (1952). Four of these slants are inoculated with lyophilized spores of Streptomyces antibioticus NRRL 3238, incubated at 28°C for 7 days or until aerial spore growth is well-advanced, and then stored at 5°C. The spores from the four slants are suspended in 40 ml of 0.1% sterile sodium heptadecyl sulfate solution. A nutrient medium having the following composition is then prepared 2.0% glucose monohydrate 1.0% soybean meal, solvent extracted, 44% protein 0.5% animal peptone (Wilson s protopeptone 159) 0.2% ammonium chloride 0.5% sodium chloride 0.25% calcium carbonate and water to make 100%. 

A bacterium is grown aerobically with glucose as sole source of carbon and ammonium ions as nitrogen source. Experimental analysis shows that six moles of glucose are utilised for each mole of biomass produced. Write the reaction equation for growth if the elemental composition of the cells is CHi,666 CW Nojd. 

ATP synthesis. For growth of Escherichia cdi on glucose and mineral salts the Y value, estimated from known cell composition and known biosynthetic pathways, is 28.8 g dry weight mol 1 ATP. However, the Y determined experimentally from yield... 

Freeze-drying of aequorin. The process of freeze-drying always results in some loss in the luminescence activity of aequorin. Therefore, aequorin should not be dried if a fully active aequorin is required. The loss is usually 10% or more. The loss can be somewhat lessened by adjusting the buffer composition the use of 100 mM KCl and some sugar (50-100 mM) seems to be beneficial. The buffer composition used at the author s laboratory is as follows 100 mM KCl, 50 mM glucose, 3 mM HEPES, 3 mM Bis-Tris, and at least 0.05 mM EDTA, pH 7.0. 

F.17 In determining the composition of an unknown compound, elemental analyses are often considered to have an error of 0.5%. With the use of elemental analyses alone, would it be possible to determine whether a sample was glucose (QHt2OJ or sucrose (C12H22On) ... 

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