Lactate reduction

The enzyme from lobster tail muscle, when assayed by lactate reduction of NAD+, is exceptional in requiring the presence of NADH for full activity 104). The enzyme from Bacillus subtilis has a specific enzymic activity which depends upon protein concentration 105). Enzymes from... 

Enzyme catalyzed reductions of carbonyl groups are more often than not com pletely stereoselective Pyruvic acid for example is converted exclusively to (5) (+) lactic acid by the lactate dehydrogenase NADH system (Section 15 11) The enantiomer... 

Optically Active PO. The synthesis of optically pure PO has been accompHshed by microbial asymmetric reduction of chloroacetone [78-95-5] (90). (3)-2-Meth5loxirane [16088-62-3] (PO) can be prepared in 90% optical purity from ethyl (3)-lactate in 44% overall yield (91). This method gives good optical purity from inexpensive reagents without the need for chromatography or a fermentation step. (3)-PO is available from Aldrich Chemical Company, having a specific rotation [0 ] ° 7.2 (c = 1, CHCl ). 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

FIGURE 19.30 (a) Pyruvate reduction to ethanol in yeast provides a means for regenerating NAD consumed in the glyceraldehyde-3-P dehydrogenase reaction, (b) In oxygen-depleted muscle, NAD is regenerated in the lactate dehydrogenase reaction. 

The standard reduction potential for (NAD /NADH) is — 0.320 volts, and the standard reduction potential for (pyru-vate/lactate) is —0.185 volts. 

Analysis of ESRB 7 mice showed fewer and smaller litters than wild type mice as well as abnormal vascular function and hypertension. The reduction in fertility was attributed to reduced ovarian efficiency. Mutant females had normal breast development and lactated normally. Older mutant males displayed signs of prostate and bladder hyperplasia. s -2-deficient mice furthermore display diverse regulatory defects in the function of brain, lung, and white blood cells. The results indicated that ESRB is essential for normal ovulation efficiency but is not essential for lactation, female or male sexual differentiation, or fertility. 

Finally in this section on deracemization via cyclic oxidation/reduction methods, there has been some limited work carried out on the deracemization of secondary alcohols. Soda et al. [22] employed lactate oxidase in combination with sodium borohydride to deracemize D/i-lactate (18) via the intermediate pyruvate (19) (Figure 5.12). 

Deinococcus radiodurans strain Rl Anaerobic cultures grown with lactate could reduce chromate, although reduction was increased by the presence of electron transfer to AQDS. Reduction of U(VI) and Tc(VII) could also be accomplished in the presence of the electron transfer agent (Fredrickson et al. 2000). 

Cellulomonas spp. Under anaerobic conditions, several strains could carry out reduction of Cr(VI) and U(VI) at the expense of lactate (Sani et al. 2002). 

Bacteria have been isolated using reduced anthraquinone-2,6-disulfonate (HjAQDS) as electron donor and nitrate as electron acceptor (Coates et al. 2002). The organisms belonged to the a-, p-, y-, and 5-subdivision of the Proteobacteria, and were able to couple the oxidation of H AQDS to the reduction of nitrate with acetate as the carbon source. In addition, a number of C2 and C3 substrates could be used including propionate, butyrate, fumarate, lactate, citrate, and pyruvate. 

Boyle AW, CD Phelps, LY Young (1999) Isolation from estuarine sediments of a Desulfovibrio strain which can grow on lactate coupled to the reductive dehalogenation of 2,4,6-tribromophenol. Appl Environ Microbiol 65 1133-1140. 

Sanford RA, JR Cole, EE Loffler, JM Tiedje (1996) Characterization of Desulfitobacterium chlororespirans sp. nov., which grows by coupling the oxidation of lactate to the reductive dechlorination of 3-chloro-4-hydroxybenzoate. Appl Environ Microbiol 62 3800-3808. 

Habicht KS, L Sailing, B Thamdrup, DE Canfield (2005) Effect of low sulfate concentrations on lactate oxidation and isotope fractionation during sulfate reduction by Archaeoglobus fulgidus strain Z. Appl Environ Microbiol 71 3110-3111. 

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