The growth of chlorella vulgaris in pure culture

Abstract

A considerable number of investigations of the physiology of the alga Chlorella is in existence, but up to the present there seems to have been no detailed description of its growth cycle. The growth of a very similar alga, Scenedesmus costulatus var. chlorelloides, has been studied by Bristol Roach (1926, 1928) in some detail, so that the general course of the growth cycle could be inferred. Bristol Roach, however, was not able to include studies of dry weight gain and chemical composition in her analysis of the problem, and these properties clearly required con­sideration in any further investigations of algal growth. Moreover, as Chlorella has been used in this laboratory in studying the effect of various factors upon its metabolism, it was especially desirable that the effects of growth status and age upon its properties and chemical composition should be defined. These considerations suggested the present investigation, which represents an attempt to study the growth of Chlorella in pure culture with particular reference to the relations between increases in number, in volume, in dry weight, and changes in chemical composition. It will be found that this aim largely determines the methods which must be used.