A soluble ferric reductase, SfrAB, which catalysed the NADPH-dependent reduction of chelated Fe(III), was previously purified from the dissimilatory Fe(III)-reducing micro-organism Geobacter sulfurreducens, suggesting that reduction of chelated forms of Fe(III) might be cytoplasmic. However, metabolically active spheroplast suspensions could not catalyse acetate-dependent Fe(III) citrate reduct...

Acetate is an end-product of anaerobic biodegradation and one the major metabolites microbial fermentation lingo-cellulosic hydrolysate. Recently, acetate has been highlighted as a feedstock to produce value-added chemicals. This study examined conversion succinate by citrate synthase (gltA)-overexpressed Pseudomonas putida under microaerobic conditions. The metabolism initiated with gltA enzym...

The aluminum (Al)-induced secretion of citrate has been regarded as an important mechanism for Al resistance in soybean (Glycine max). However, the mechanism of how Al induces citrate secretion remains unclear. In this study, we investigated the regulatory role of plasma membrane H+-ATPase on the Al-induced secretion of citrate from soybean roots. Experiments performed with plants grown in full...

Citrate metabolism in Leuconostoc mesenteroides subspecies mesenteroides is associated with the generation of a proton motive force by a secondary mechanism (C. Marty-Teysset, C. Posthuma, J. S. Lolkema, P. Schmitt, C. Divies, and W. N. Konings, J. Bacteriol. 178:2178–2185, 1996). The pathway consists of four steps: (i) uptake of citrate, (ii) splitting of citrate into acetate and oxaloacetate,...

Rubella virus was centrifuged in sucrose density gradients. One of two densities could be ascribed to the virus, depending upon the suspending medium used. The virus was found at a density of 1.16 g/cm(3) after centrifugation for 18 hr in sucrose gradients prepared in distilled water. By contrast, when the sucrose gradients were prepared in tris(hydroxymethyl)aminomethane (Tris)buffer containin...

The treatment of the industrial wastewater can be particularly difficult in the presence of toxic compounds. Excessive concentration of Chromium in soluble form is toxic to a wide variety of living organisms. Biological removal of heavy metals using natural and genetically engineered microorganisms has aroused great interest because of its lower impact on the environment. Ralston metallidurans,...

L1210 leukemic cells can be cultured continuously in serum-free medium supplemented merely with either transferrin or iron salts. No transferrin or transferrin-like molecules were detected in the conditioned medium from cells established in serum-free medium plus iron. In these cells, iron uptake was found to occur through a saturable transport system exhibiting the properties of an allosteric ...

I 121(1 leukemic cells can be cultured continuously in serum-free medium supplemented merely with either transferrin or iron salts. No transferrin or transferrin-like molecules were detected in the conditioned medium from cells established in serum-free medium plus iron. In these cells, iron uptake was found to occur througha saturable transportsystem exhibiting the properties of an allosteric ...

FERGUSON, R. A., and STOREY, K. B. 1991. Citrate synthase in the rainbow trout heart: regulation by pH, temperature, and metabolite levels. Can. J. Zool. 69: 3020-3027. Crude homogenates of rainbow trout (Oncorhynchus mykiss) hearts have high citrate synthase activity (30 units per gram wet weight at 20°C), reflecting the aerobic nature of this organ. Citrate synthase was purified 70-fold by po...