Jul 23, 1976

Chlorate toxicity in Aspergillus nidulans. Studies of mutants altered in nitrate assimilation

Molecular & General Genetics : MGG
D J Cove

Abstract

It had previously been held that chlorate is not itself toxic, but is rendered toxic as a result of nitrate reductase-catalysed conversion to chlorite. This however cannot be the explanation of chlorate toxicity in Aspergillus nidulans, even though nitrate reductase is known to have chlorate reductase activity. Among other evidence against the classical theory for the mechanism of chlorate toxicity, is the finding that not all mutants lacking nitrate reductase are clorate resistant. Both chlorate-sensitive and resistant mutants lacking nitrate reductase, also lack chlorate reductase. Data is presented which implicates not only nitrate reductase but also the product of the nirA gene, a positive regulator gene for nitrate assimilation, in the mediation of chlorate toxicity. Alternative mechanisms for chlorate toxicity are considered. It is unlikely that chlorate toxicity results from the involvement of nitrate reductase and the nirA gene product in the regulation either of nitrite reductase, or of the pentose phosphate pathway. Although low pH has an effect similar to chlorate, chorate is not likely to be toxic because it lowers the pH; low pH and chlorate may instead have similar effects. A possible explanation for chlorate toxi...Continue Reading

Mentioned in this Paper

Antibiotic Resistance, Microbial
Aspergillus Niger Infection
Chlorates
Genes, Regulator
Nitrates
Aspergillus nidulans
Hydrogen-Ion Concentration

About this Paper

Related Feeds

Antimicrobial Resistance (ASM)

Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections.

Allergy & Infectious Diseases

Allergies result from the hyperreactivity of the immune system to some environmental substance and can be life-threatening. Infectious diseases are caused by organisms including bacteria, viruses, fungi and parasites. They can be transmitted different ways, such as person-to-person. Here is the latest research on allergy and infectious diseases.

Allergy & Infectious Diseases (ASM)

Allergies result from the hyperreactivity of the immune system to some environmental substance and can be life-threatening. Infectious diseases are caused by organisms including bacteria, viruses, fungi and parasites. They can be transmitted different ways, such as person-to-person. Here is the latest research on allergy and infectious diseases.

Antimicrobial Resistance

Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections.