Phosphate containing reaction mixtures

The EMIT protocol was followed through the production of NADH. The 50 fxl of the NADH-containing reaction mixture was diluted 11 1 with 0.1 M phosphate pH 7.4, vortexed, and sampled by HPLC. Under the conditions used the NADH residence time on the Knauer column was 2 min 47 sec. Tubes were processed every 12 min in this manner. 

Use of Coagulants Coagulants may also react with other constituents of the wastewater, particularly anions such as phosphate and sulfate, forming hydrolysis products containing various mixtures of ions. The chemistry of the reactions is extremely complex and highly dependent on pH and alkalinity. The presence of... 

Reduction by sodium dithionite. A small amount of sodium dithionite, solid or in solution, is added to a luciferase solution made with 50 mM phosphate, pH 7.0, containing 50 pM FMN. The amount of dithionite used should be minimal but sufficient to remove oxygen in the solution and to fully reduce the flavin. The solution made is injected into an air-equilibrated buffer solution containing a long-chain aldehyde and luciferase to initiate the luminescence reaction. With this method, the reaction mixture will be contaminated by bisulfite and bisulfate ions derived from dithionite. 

Since the equilibrium reaction mixture contains at least four products, workup can be difficult and therefore, it may be helpful to bring the reaction to completion. For example, in the transketolase-catalyzed reaction of [l-13C]D-ribosc 5-phosphate and [l-l3C]D-i/ /w-2-pen-tulose 5-phosphatc to [l,3-13C]n-a/b,o-2-heptulose 7-phosphate and D-glyceraldehyde 3-phos-... 

In die case of nylon-6,6 waste recycled by ammonolysis, nylon is treated with ammonia in die presence of a phosphate catalyst. Reaction occurs at 330°C and 7 MPa. Distillation of die reaction mixture produces ammonia which is recycled and three fractions containing (a) caprolactam, (b) HMDA and aminocaproni-trile, and (c) adiponitrile. Aminocapronitrile and adiponitrile are hydrogenated to yield pure HMDA, and die caprolactam is eidier converted to aminocapronitrile by further ammonolysis or distilled to produce pure caprolactam. The HMDA produced by this process is extremely pure (>99.8).1 The main impurities are aminomediylcyclopentylaniiiie and tetrahydroazepine, which are expected to be removed more effectively in the larger distillation columns employed in the larger plants. 

An excess of PGD is added to the reaction mixture containing glucose 6-phosphate and NADP to assure that 2 moles of NADPH are produced per mole of glucose-6-phosphate oxidized (109). This method has been improved by Nicholson et. al (110) to make... 

The carboxylafion of indole into indole-3-carboxylate was observed by the purified indole-3-carboxylate decarboxylase as well as by the whole cells. For the carboxylafion reaction, temperatures over 30°C were not appropriate. The activities at 10, 20, and 30°C were about the same. The activity was maximal at pH 8.0 (Tris-HCl buffer, 100 mM). As shown in Fig. 10, the resting cells of A. nicotianae F11612 also catalyzed the carboxylafion of indole efficiently in the reaction mixture containing 20 mM indole, 3M KHCO3, 100mM potassium phosphate buffer (pH 6.0) in a tightly closed reaction vessel. By 6h, 6.81 mM indole-3-carboxylic acid accumulated in the reaction mixture with a molar conversion yield of 34%. Compared to the carhoxylation of pyrrole by pyrrole-2-carboxylate decarboxylase, the lower value compared might derive from the lower solubility of indole in the reaction mixture. 

Dissolve a protein or macromolecule containing primary amines at a concentration of 10 mg/ml in 50 mM sodium phosphate, 0.15 M NaCl, pH 7.2. Other non-amine-containing buffers such as borate, HEPES, and bicarbonate also may be used in this reaction. Avoid sulfhydryl-containing components in the reaction mixture as these will react with the pyridyl disulfide end of SPDP. The effective pH for the NHS ester modification reaction is in the range of 7-9, but hydrolysis will increase at the higher end of this range. 

Fig. 1. — Effect47 of Tomato Pectinesterase on the Activity of Pectate Lyase Acting on Highly Esterified Pectin. [Reaction mixtures contained 0.5% of D-galacturonan (broken line) or poly(D-galacturonic acid methyl ester) methyl glycoside (solid lines), 5 mM CaCl2, 33 mM phosphate buflFer (pH 7.0), and 0.25 unit of lyase in a final volume of 3.0 ml. In addition, the reaction mixture represented by the middle curve contained 0.031 unit of tomato pectinesterase in a final volume of 3.3 ml.] Reprinted, with permission, from M. Lee and J. D. Macmillan, Biochemistry, 9, 1930-1934 (1970). Copyright by the American Chemical Society.

The determination of GSSGR activity is based upon Eq. (8) and can be followed spectrophotometrically by the decrease of NADPH2 absorbance at 340 or 366 mp. For the above-mentioned reasons phosphate buffer may be preferred. The typical reaction mixture contains in a final volume of 3.0 ml (H20) 1.6 to 2,4 ml phosphate buffer as described by Sorensen (0.076 M, pH 6.5) 0.2 ml NADPH2 (0.4 [junole per test volume) 0.2 ml GSSG solution (1.5 X 10 3M and equilibrated to pH 6.3-6.4 with NaOH) and 0.2-0.8 ml of serum. The blank contains water instead of substrate solution. Readings are taken at 340 or 366 mp at room temperature at one-minute intervals, the light path being 1.0 cm. The decrease in absorbance should not exceed 0.03 per minute. 

The crude product after kinetic resolution of racemic phenylbutan-2-one was dissolved in 10 mL hexane and transferred to a reaction flask containing 100 mg CAL-A in 50 mL phosphate buffer. The reaction mixture was stirred for 24 h at 30 °C. 

Purified LCCs (10 mg dry weight) were incubated at 50°C for 3 h with 50 units of each enzyme alone and in specified combinations in a total volume of 1.0 mL. Reaction mixtures contained a final concentration of 20 mM potassium phosphate buffer, pH 6.0. Enzyme digests were then fractionated on columns of Sephadex G-50 or Sephadex G-10 as described above. 

The particle size of each polyester powder was ranked A, B, C, D, or E, corresponding respectively to roughly less than 0.25 mm, less than 0.50 mm, less than 1.0 mm, 0.25-1.5 mm, 0.25-3 mm. Each reaction mixture contained ioo p mol of phosphate buffer (pH T.O), 1 mg of surfactant Plysurf A210G, 300 mg of the polyester powder and 60 y g of R. arrhizus lipase (or 300 pg of R. delemar lipase) in a total volume of 10.0 ml. In the case of R. delemar lipase, surfactant was omitted and pH of phosphate buffer was 6.0. In the substrate and enzyme controls, enzyme or substrate was omitted from the reaction mixture. 

Peroxidase activity was based on the polymerization rate of guaiacol in the presence of hydrogen peroxide (10). The reaction mixture contained 2.0 ml 13 mM potassium phosphate buffer (pH 7.0) containing 5 mM H2O2,... 

The oxidation of veratryl alcohol was carried out under air at room temperature. The reaction mixture contained 30 //moles of veratryl alcohol, 0.05 //moles of TDCSPPFeCl, 30 //moles of m-chloroperbenzoic acid (mCPBA) made up to 6 ml using phosphate buffer or as otherwise indicated in Table... 

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