A bacterium, strain PC-07, previously isolated as part of a coculture capable of growing on p-cresol under anaerobic conditions with nitrate as the acceptor was identified as an Achromobacter sp. The first enzyme of the pathway, p-cresol methylhydroxylase, which converts its substrate into p-hydroxybenzyl alcohol, was purified. The enzyme had an Mr of 130,000 and the spectrum of a flavocytochro...

Palladized biomass of Desulfovibrio vulgaris (Bio-Pd(0)) reduced Cr(VI) to Cr(III) at an initial rate four-fold higher than chemically-prepared Pd(0) metal. Optimal Cr(VI) reduction by suspended BioPd(0) occurred at pH 3, whereas pH did not affect the rate of Cr(VI) reduction by Bio-Pd(0) immobilized in agar beads. The rate of Cr(VI) reduction was concentration-dependent below 300 μmol dm−3, an...

During neuronal communication neurotransmitters are released through the process exocytosis that occurs on the time scale of sub-milliseconds to milliseconds. Neuronal activity by neurotransmitters that are non-electroactive cannot easily be monitored due to limitations in the temporal resolutions of the sensor probes for these analytes. In order to achieve a fast detection of the rapid transie...

Consequences of directional selection on metabolic flux are explored in models for which variation in flux among individuals is generated by segregation of allelic variants at enzyme activity loci. The pattern of selection response is strongly affected by the presence of genetic dominance and epistasis, which are automatically generated in metabolic systems. The expected magnitudes of dominance...

The effect of 30-day dark deprivation (light-dark cycle 24/0 h, artificial illumination 300 Lux) on the morphofunctional state testes was studied using morphological and morphometric analysis histological preparations white mongrel male rats 4 months age. level follicle-stimulating hormone in blood serum assessed by enzyme immunoassay. It found that increases serum. Morphological changes were c...

We measured the activity of cytosolic and of mitochondrial malic enzyme in the hearts from 4 patients with Friedreich's disease and from two non-ataxic control subjects. There was a wide variability in the results and the slight overall decreases in both enzyme activities were not considered to be statistically significant. From these and other results, we conclude that deficient mitochondrial ...

The three dimensional structure of an enzyme is of fundamental importance to almost every function it performs. In this thesis, we aim to analyse the structures of many enzymes in order to gain insights into how they perform catalysis, and the role of structure in enzyme function. As well as improving our understanding of these important biological molecules, these insights will help in develop...