curva de sobrevivência à luz ultravioleta do Azospirlllum brasilense (BEIJERIWCK, 1925)

Abstract

Study of Azospirillum brasilense, a bacterium that acts to fix nitrogen in gramineous plants, with the aim of aiding genetic-studies concerned with A. brasilense by means of determining the survival curve for the microorganism exposed to ultraviolet light. A time span of one minute of exposure to radiation was established, and a 5% rate of survival was obtained, representing a recommendable dosage for the induction of mutations, provided that the DNA of the bacteria be sufficiently exposed to the mutagenic agent without, however, drastically reducing the irradiated population, as a radical reduction would cause the frequency of mutants after treatment to become very low.