Abstract
The effects of glucose and sodium chloride supplemented in culture media, initial pH of the media and cultural temperature upon bacterial growth were examined in connection with inoculum size using a Biophotometer (Jouan, Paris) which monitors turbidity of the cultures continuously. The bacterial growth was estimated on the basis of lag time and growth rate. The growth rate was derived from L10, which is the time of reduction of lag time when inoculum size is increased ten times. In higher concentrations, glucose and sodium chloride greatly influenced the lag time and growth rate of bacteria, but the concentrations affecting the growth varied with strains. The effect similar to those of glucose and sodium chloride was observed in lower initial pHs. Even when inoculum size was changed, growth rate of bacteria was not affected by these environmental factors. Temperature also influenced both lag time and growth rate. In the range of temperatures tested, lag time became longer and growth rate smaller at lower temperatures than at higher temperatures. Moreover, the growth rate in a large inoculum size was greater than that in a small inoculum size. The effect of inoculum size was discussed from the viewpoint of bacterial growth.
