BEHAVIOUR OF HUMULONE DURING ITS BACTERIO STATIC PERIOD

When humulone in sufficiently large quantity is added to growing cultures of Lactobacillus easel under the test conditions described, growth immediately stops; the antibacterial potency of the culture thereafter progressively declines and eventually disappears, so that normal growth is resumed. The cells, immediately after humulone addition, seem to be biologically affected to a small extent and some lysis occurs, but no detrimental effect can be detected in cells harvested at the end of the humulone‐induced lag phase. With this phase completed, the cells are not less sensitive to humulone; they are not adapted to humulone any more than they were before humulone addition, and the ultimate resumption of normal growth is apparently due to complete destruction of antibacterial activity by components of the medium itself.