The Production Of Spores in Submerged Cultures By Some Streptomyces

SUMMARY

1.	Information on the life cycle of the fungus S. griseus in submerged cultures is reported. The spores first germinated and produced profuse vegetative and typical fungous mycelium. Vacuolation, fragmentation and cellular disintegration of the mycelium was evident during fermentation in deep cultures, accompanied usually by the formation of large numbers of spores.
2.	Submerged spores could be produced in a shorter time and in much larger quantities than spores produced on the aerial mycelium on the surface of solid or liquid media.
3.	The mycelial fragments may germinate at any place by one to several germ tubes, similar to those produced by the spores.
4.	In some instances at a certain age of fermentation, little or no mycelium was found in the broth; but the number of viable spores was profuse.
5.	Submerged spore production may start within twenty-four hours after the fermenters are seeded. The submerged sporulation in large fermenters usually appears in a shorter time than in shake flasks.
6.	All the S. griseus strains studied produced spores in submerged cultures. Some differences were found among strains in regard to the time and amount of sporulation.
7.	The spores were found to be formed in chains: (1) In sporogenous branches arising from the vegetative mycelium; (2) at the tips of vegetative mycelium; (3) in the mycelium, in the main axis and secondary branches; (4) in mycelial fragments; and (5) in the germ tubes of spores and mycelial fragments.
8.	The spores produced in submerged cultures were smooth and wettable. The physiological and morphological characteristics of submerged spores and of the aerial spores produced on the mycelium on solid or liquid media were similar.
9.	Other species of the genus Streptomyces, S. lavendttlae, S. albus and a Streptomyces sp., produced submerged spores in deep cultures. The morphological changes exhibited by these organisms during fermentation were very similar to those of S. griseus strains.
10.	Colonies of S. griseus, submerged in nutrient agar, produced a large number of spores within two to twelve days at room temperature.