[Maintenance metabolism in glucose-limited chemostat cultures of Streptomyces hygroscopicus].

Investigations with the mycelium forming bacterium Streptomyces hygroscopicus IMET JA 6599 in glucose-limited chemostat cultures gave a maintenance coefficient of m = 0.031 h-1. This low maintenance coefficient corresponds to those of moulds (RIGHELATO et al. 1968, CARTER et al. 1971). With a simple model structured in active and inactive biomass (x1 and x2) it was tried to explain the low maintenance coefficient of S. hygroscopicus in relation to nonfilamentous growing microorganisms. The model contains the transition rate k, which describes the transition of active biomass in inactive one and the decay rate beta, which considers the decay of hyphae. The model was used to study the influence of beta on the maintenance coefficient and it was shown that maintenance metabolism can be simulated by the parameter beta alone.