Continuous Recording of the Growth of Micro-Organisms under Turbidostatic and Chemostatic Control

Abstract

The microbial auxanometer, an instrument which automatically records the growth rate of a micro‐organism during its continuous growth under turbidostatic control, has been developed further to provide (1) interchangeable turbidostatic and chemostatic control, (2) automatic recording of culture density under chemostatic control or during uncontrolled growth, and (3) improvements in growth tube design which reduce cell trapping. The instrument delivers a continuous record of the growth history of the organism under either free‐growing or growth‐factor‐limited conditions and of changes in growth rate induced by physical or chemical means. It is well adapted to the study of spontaneous and induced mutation rates.