INVESTIGATION OF FACTORS INFLUENCING RADIATION RESISTANCE OF MICROCOCCUS RADIODURANS

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1963

OSTI ID:4022582

Lee, J S

Age-dependent fluctuation of radiation resistance of Micrococcus radiodurans was investigated. The fluctuation observed in cells grown in synthetic media was less than 10% during 44 hrs of growth. The cells harvested 9 hrs after inoculation were the most radiation resistant. The wet mass and DNA contents of these cells were low. When the culture was shifted'' from the synthetic media to tryptone-glucose-yeast extract media, the survival dropped from 12 to 4% but it rebounded to 15% in the subsequent 60 min. The DNA content of these cells was low in comparison to cell mass. Alkyliodides, 2,4- dinitrophenol, diphenylamine, malonic acid, maleic acid, ethylenediaminetetraacetate, N-ethylmaleimide, and iodoacetic acid were investigated for their radiation-enhancing effects on resting M. radiodurans cells in buffer. Among them, iodoacetic acid (IAA) was the most effective. IAA, at a nontoxic level of 100 mu M, reduced the survival 1,000 fold at all levels of radiation. This radio-toxic effect was observed only when cells were irradiated in the presence of IAA. IAA also enhanced radiation bleaching of carotenoid pigments in the cells and produced with starch a blue-violet color upon irradiation. The starch-IAA mixture was developed as a chemical radiation dosimeter. The range of this dosimeter was from 30,000 to 500,000 rads. (Dissertation Abstr., 29: No. 8, Feb. 1964)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-019751
• OSTI ID: 4022582
• Resource Relation: Other Information: Thesis. Orig. Receipt Date: 31-DEC-64
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
ACETIC ACID
AGE
AMINES
BACTERIA
CHEMICAL REACTIONS
COLOR
DNA
DOSEMETERS
EDTA
GROWTH
IODIDES
MALEIC ACID
MALONIC ACID
METHYL RADICALS
MICROCOCCUS RADIODURANS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC IODINE COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOLS
PHENYL RADICALS
PIGMENTS
RADIOSENSITIVITY
SENSITIVITY
SURVIVAL TIME
TOXICITY
VARIATIONS