Postirradiation recovery dependent on the uvr-1 Locus in Bacillus subtilis. [UV radiation]

Journal Article · Fri Oct 01 04:00:00 EDT 1976 · J. Bacteriol.; (United States)

OSTI ID:7333888

Hadden, C T

A mutant (uvr-1) of Bacillus subtilis that is deficient in excision of ultraviolet (uv)-induced pyrimidine dimers from deoxyribonucleic acid (DNA) shows a marked increase in ability to survive uv irradiation when plated on amino acid-supplemented agar medium compared with its survival ability when plated on nutrient agar. Since the extent of killing depends on the richness of the plating medium, the effect is considered to be one of growth-dependent lethality. Irradiated stationary phase uvr-1 cells, incubated in liquid medium lacking amino acids required for growth, recover from this sensitivity to rich medium within 3 to 4 h after irradiation. Recovery is greatly reduced in the absence of glucose or in the presence of NaCN, athough it is not completely eliminated. Exponentially growing cells have a limited ability to recover from sensitivity to rich medium. Growth-dependent lethality can also occur in liquid medium. In nutrient broth the ability of irradiated stationary-phase uvr-1 cells to form colonies on defined agar medium decreases during postirradiation incubation, but treatment with chloramphenicol inhibits the loss of colony-forming ability. Recovery from sensitivity to rich media is inhibited by caffeine but not by 6-(p-hydroxyphenylazo)-uracil, an inhibitor of DNA replication. Alkaline sucrose gradient profiles show that conditions allowing recovery also favor maintaining intact DNA strands, whereas DNA strand breakage or degradation is associated with loss of viability.

• Research Organization: Univ. of Tennessee--Oak Ridge Graduate School, Oak Ridge, TN
• OSTI ID: 7333888
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 128:1; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
ANTIBIOTICS
AZINES
BACILLUS
BACILLUS SUBTILIS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
CAFFEINE
CARBOXYLIC ACIDS
CFU
CHLORAMPHENICOL
DIMERS
DNA
DRUGS
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
MICROORGANISMS
MUTANTS
MUTATIONS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PURINES
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RECOVERY
SURVIVAL TIME
ULTRAVIOLET RADIATION
XANTHINES