Characterization of an activity from the strict anaerobe Roseburia cecicola that degrades DNA when exposed to air.

AUTOR(ES)

O'Connor, L T

RESUMO

Roseburia cecicola is an obligately anaerobic bacterium that is extremely sensitive to oxygen. Genomic DNA isolated from cells exposed to air for even a brief period (< 5 min) is partially degraded, while DNA extracted from cells maintained in an anaerobic environment remains intact. Cells exposed to air for longer and longer periods yield DNA which is progressively degraded into fragments with decreasing sizes. Oxygen toxicity for this anaerobe appears to result, at least in part, from degradation of its genomic DNA. Cell lysates of the organism exhibited a similar ability to degrade exogenous sources of DNA when assayed in vitro under aerobic conditions. A substance that degrades both DNA and RNA when incubated aerobically was partially purified from such lysates. It has an approximate molecular weight of 2,800 and is unlikely to be a protein. It requires a reducing agent for activity and can be inhibited by catalase and peroxidase but not superoxide dismutase. The rate at which it degrades DNA in vitro can be enhanced by temperatures above 37 degrees C or by oxygen at partial pressures above atmospheric pressure. These results suggest that this substance degrades nucleic acids by a mechanism involving oxygen radicals.

Documentos Relacionados

• Degradation of DNA in cells and extracts of the obligately anaerobic bacterium Roseburia cecicola upon exposure to air.
• Cloning, nucleotide sequence, and taxonomic implications of the flagellin gene of Roseburia cecicola.
• Colonization of gnotobiotic mice by Roseburia cecicola, a motile, obligately anaerobic bacterium from murine ceca.
• Assessment of broiler surface temperature variation when exposed to different air temperatures
• Building Hyphae in the Air.