Growing Escherichia coli mutants deficient in riboflavin biosynthesis with non-limiting riboflavin results in sensitization to inactivation by broad-spectrum near-ultraviolet light (320-400 nm)
| Autor: | B A Hug, J L Rinkenberger, R. E. Lloyd, R W Tuveson |
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| Rok vydání: | 1990 |
| Předmět: |
Ultraviolet Rays
Auxotrophy Riboflavin Mutant medicine.disease_cause Biochemistry chemistry.chemical_compound Biosynthesis medicine Extracellular Escherichia coli heterocyclic compounds Physical and Theoretical Chemistry biology digestive oral and skin physiology food and beverages General Medicine biology.organism_classification Enterobacteriaceae chemistry Mutation human activities Bacteria |
| Zdroj: | Photochemistry and photobiology. 52(4) |
| ISSN: | 0031-8655 |
| Popis: | Two mutants of Escherichia coli unable to synthesize riboflavin were grown with limiting (2 micrograms ml-1) and non-limiting (10 micrograms ml-1) concentrations of riboflavin. These riboflavin auxotrophs when grown to exponential phase with non-limiting riboflavin are more sensitive to broad spectrum near-ultraviolet light (NUV, 320-400 nm) inactivation than when they are grown with limiting riboflavin. Exponential phase cells of the riboflavin auxotrophs grown with limiting riboflavin are sensitized when irradiated in saline supplemented with riboflavin. This suggests that extracellular riboflavin is important as a NUV sensitizer when intracellular levels of riboflavin are reduced. The concentration of riboflavin in crude extracts from exponentially growing cells correlates well with the sensitivity of these mutants to NUV inactivation. The level of riboflavin supplementation has little effect on the NUV sensitivity of the parental strain. |
| Databáze: | OpenAIRE |
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