Abstract
On the basis of cytological examination, the life cycle of Streptomyces griseoflavus appears to consist of the following phases: 1) a vegetative phase (a primary mycelium) which develops after conidial germination; and 2) a sporulation phase (a secondary mycelium). Frequently the sporulation phase is the consequence of direct maturation of primary mycelium. The primary mycelium may give rise to three diverse and distinctive structures; namely, “nests”, “swollen bodies” and “clubs”. These appear to correspond to “initial cells” discussed in the literature and may represent a transition period between the vegetative and sporulation phases of growth. However, the present investigation suggests that such a transition period is not obligatory in the life cycle of Streptomyces griseoflavus. The secondary mycelium gives rise to conidia which contain single diploid or bipartite nuclei by a process of fragmentation or segmentation.
