Changes in the surface tension of broth produced by the growth of bacteria.

Abstract

In work published from this laboratory, it has been shown that growth of bacteria is influenced by the surface tension of the culture medium. This fact has been recently emphasized further by the work of Ayers, Rupp and Johnson. 1

The present study concerns the changes in the surface tension of broth produced by bacterial growth. Four samples of 1 per cent peptone broths were prepared in the usual way with some of the well known brands of peptones. They were inoculated with the B. subtilis and B. coli, respectively. The surface tensions were measured at 48 hour intervals by the drop weight method after clarifying the cultures by rapid centrifugation.

The changes in surface tension are indicated by the accompanying graphs.