Effect of temperature and medium composition on mycelial growth of Streptomyces tendae in submerged culture.

To investigate the influence of culture conditions on growth of filamentous bacteria in submerged culture, S. tendae was cultivated at various temperatures and in various media. For this purpose, a temperature-controlled growth chamber was constructed, which allows the cultivation of filamentous bacteria and fungi oxygen saturated medium. To observe the development of mycelia emerging from spores, this growth chamber was mounted on a microscope stage and series of images were analyzed by an image processing system. Growth kinetics obtained in liquid culture were identical to those determined on solid media. Specific growth rate and apical extension rates of individual hyphae seemed to be higher than those observed on solid media, due to a better supply of medium in submerged culture. A two-fold increase in specific growth rate, mean apical extension rate and branching rate was observed when the temperature was increased from 27 degrees C to 37 degrees C, therefore, the length of the hyphal growth unit was not changed. Growth in synthetic media used here was considerably slower compared with complex medium. A decrease in glucose concentration from 40.0 g l-1 to 1.0 g l-1 resulted in an increase in branching rate and specific growth rate, while apical extension rate of individual hyphae was unchanged.