Contamination of perchlorate and chlorate in nature is primarily the result of various industrial processes. The microbial respiration of these oxyanions of chlorine plays a major role in reducing the society’s impact on the environment. The focus with this thesis is to investigate the oxygen-dependent regulation of key components involved in the chlorate respiration in the gram-negative bacter...

Chlorate reductase has been isolated from the chlorate-respiring bacterium Ideonella dechloratans, and the genes encoding the enzyme have been sequenced. The enzyme is composed of three different subunits and contains molybdopterin, iron, probably in iron-sulfur clusters, and heme b. The genes (clr) encoding chlorate reductase are arranged as clrABDC, where clrA, clrB, and clrC encode the subun...

Strain GR-1 is one of several recently isolated bacterial species that are able to respire by using chlorate or perchlorate as the terminal electron acceptor. The organism performs a complete reduction of chlorate or perchlorate to chloride and oxygen, with the intermediate formation of chlorite. This study describes the purification and characterization of the key enzyme of the reductive pathw...

The influence of chlorate, an inhibitor of sulfate adenylyltransferase, on biosynthesis and secretion of proteoglycans was investigated in cultured human skin fibroblasts. At up to 10 mM concentrations, chlorate caused a reduction of [35S]sulfate incorporation into small chondroitin sulfate/dermatan sulfate proteoglycan by up to 96%. Incorporation of [3H]leucine and [3H] glucosamine was only sl...

The functional influence of cell proteoglycan (PG) undersulfation on estradiol synthesis by immature rat Sertoli cell cultures was investigated by using sodium chlorate, an inhibitor of the active sulfate donor for sulfotransferases. The addition of sodium chlorate to 20-day-old rat Sertoli cell cultures abolished [35S]-sulfate incorporation into neosynthesized PG and consequently reduced the r...

A comparative study has been carried out of the growth of two lines of Datura innoxia (Mill.) cells, designated DI-6 and NR1, their resistance to chlorate, and their ability to assimilate nitrate in sterile culture. The NR1 cell line was isolated from DI-6 cultures by first growing the latter in a nitrate-based medium for 5 days and then transferring the cells to a medium containing 2 grams lit...

The reduction mechanism of molybdenum-methyl thymol blue (MTB)-chlorate system has been investigated in water on a mercury electrode. As this system is very sensitive for ultratrace determination of molybdenum, the actual mechanism involved was studied. Electrochemical techniques, including dc tast polarography and cyclic voltammetry were employed. It is shown that, the cathodic wave of mol...

Foodborne diseases caused by enterohemorrhagic Escherichia coli, Salmonella, and Campylobacter species are of public health and economic significance. Shedding of these pathogens during production and slaughter are risks for contamination of products for human consumption. Consequently, strategies are sought to prevent or reduce the carriage of these pathogens in food animals before slaughter. ...

Environmental contamination with compounds containing oxyanions of chlorine, such as perchlorate or chlorate [(per)chlorate] or chlorine dioxide, has been a constantly growing problem over the last 100 years. Although the fact that microbes reduce these compounds has been recognized for more than 50 years, only six organisms which can obtain energy for growth by this metabolic process have been...