GROWTH OF ESCHERICHIA COLI ON THE SURFACE OF AN ANION-EXCHANGE RESIN IN CONTINUOUS FLOW SYSTEM

[摘要] Suspension of Escherichia coli adsorbed on an anion-exchange resin, Dowex 1, was incubated in continuously flowing growth medium at D=1, the value being above a critical dilution rate. At D=1, it is possible to follow the growth of adsorbed cells separately from that of free cells since cells freely suspended in the liquid phase of culture are rapidly washed out from the system, though the latter population might be growing under the condition.Cell concentration in the liquid phase of culture at first increased stepwise with regular periodicity (first phase) and secondly kept a steady level in proportion to the initial number of adsorbed cells (second phase). Periodic change of cell concentration in the first phase is explained by division and detachment of new-born cells from the resin surface according to age distribution of adsorbed cells. The length of each period depends on the pH of the medium and reflects the generation time of adsorbed cells. From the level of cell concentration in the second phase, growth rate with adsorbedcells is calculated and it is concluded that the growth rate with adsorbed cells is considerably larger than that with free cells.

[学科分类] 微生物学和免疫学