Kinetic characterization of sporulation in Streptomyces albidoflavus SMF301 during submerged culture.

We report the first quantitative analysis of the relationship between environmental changes and sporulation of a streptomycete, Streptomyces albidoflavus SMF301, in submerged culture. A chemically defined medium was constructed for sporulation, over 10(9) spores ml-1 being formed in the submerged batch culture. Kinetic parameters calculated from batch and chemostat cultures showed that specific submerged spore formation rate (qspo) was inversely related to the specific mycelial growth rate (mu). The optimum growth rate for submerged spore formation was 0.05 h-1, when the maximum value of qspo was 1.0 x 10(6) spores g-1 h-1. The turnover rate of biomass at maximum growth yield was 0.029 h-1, when 5.6 x 10(6) spores were formed from 1 g mycelium. The present quantitative analysis of submerged spore formation using a controlled system opens the way for biochemical and molecular biological studies related to the morphological differentiation of Streptomyces spp.