Evidence for a beneficial influence of cellulose production on growth ofAcetobacter xylinum in liquid medium.

Cultures of cellulose-deficient cells ofAcetobacter xylinum that were isolated from solid medium revert from the cellulose-deficient condition to the normal, cellulose-producing, form after five transfers in liquid medium. In addition, serial cultures of initial mixtures of cellulose-deficient cells and normal cells in the ratio of 9 to 1 show a rapid decrease in the proportion of deficient cells so that after seven transfers in liquid medium there is less than, 1% of cellulose-deficient cells. These results demonstrate that, in liquid medium, cells which are normal in cellulose production overgrow those which are deficient in this capacity. They are interpreted to suggest that cellulose production in liquid medium helps this obligate aerobe to obtain a limited supply of oxygen by floating the cells close to the surface.