FURTHER STUDIES ON THE GROWTH CYCLE OF AZOTOBACTER

Abstract

At the 1912-1913 meetings of the Society of American Bacteriologists the writer read a paper entitled "A Morphological and Cultural Study of Some Azotobacter," using a series of lantern slides of photomicrographs for illustration. The paper was subsequently published in the Centralblatt fur Bakteriologie, 1913, and in the "Transactions of the Royal Society of Canada" of the same year. Among the observations made in this paper was one regarding the formation in azotobacter cells of two types of granules, one type being stainable, and the other non-stainable, with various bacterial stains. The type that was stainable appeared to represent reproductive bodies or gonidia which on disintegration of the mother cell were liberated, after which they grew into normal azotobacter cells and reproduced by fission for a time until later the cells became granular and again disintegrated with the liberation of reproductive granules. The formation of these reproductive granules with their liberation, on the disintegration of the mother cell, appeared to the writer to constitute a new type of multiplication for azotobacter distinct from the usual method of fission characteristic of bacteria in general. As no reference to such a method of multiplication could be found in the literature, the observations were repeated a considerable number of times to verify the above conclusions.