Probabilistic features of the proliferation of soil bacteria.

Abstract

Previously (1) it was found that bacterial populations developed in capillary tubes inserted into soil consist of offspring of one or a few cells among several hundred cells originally existing at the tip of each tube. From a statistical view, processes of the proliferation of bacteria at microsites of soil structure were characterized as rare events. In the present report, bacteria dispersed into soil suspension were also shown to proliferate in the same way both in capillary tubes and on plates, and colony formation of soil bacteria on counting plates was expected to follow the equationln (N0-N)=ln N0-λtwhere N0 is the number of bacteria capable of forming colonies, N, that of colonies found at time t and λ a parameter. Various data on plate counting were shown to fit the equation. Size distribution of colonies on counting plates was also supposed as being interpretable from a statistical view.