RESUMEN
When Streptomyces roseoflavus var. roseofungini is grown as a submerged culture in a chemically defined medium with stirring, it yields a number of variants in which the capacity to form the aerial mycelium is disturbed. Inoculations of the submerged mycelium of different age into a solid medium give rise to both "tomentose" variants (TV) with the aerial mycelium and "naked" variants (NV) lacking the aerial mycelium. The latter variants comprise Nocardia-like variants (NLV) with the fragmenting mycelium. The following change in the variants occurs in the inoculations of the submerged mycelium in the course of the cultural growth: TV leads to NV leads to NLV or (more rarely) TV leads to NLV. The dynamics of accumulation of the variants depends, to a considerable extent, on the source of carbon in the medium: NLV first appear on the medium containing fructose; NV are detected first on the medium with glucose; NV are rarely found on the medium with mannitol. In aged cultures, the number of NLV can reach 80--90%, the content of TV is 20--10%, and NV are absent. The above results suggest that the formation of NLV from S. roseoflavus var. roseofungini is the result of stepwise selection.
Asunto(s)
Variación Genética , Streptomyces/crecimiento & desarrollo , Medios de Cultivo , Fructosa/metabolismo , Glucosa/metabolismo , Glicerol/metabolismo , Manitol/metabolismo , Streptomyces/metabolismo , Factores de TiempoRESUMEN
It was shown that adifferentiated nocardioform variants (NV) of Streptomyces roseoflavus var. roseofungini 1128 may appear in mycelial cell suspensions of submerged actinomycete cultures in water, phosphate buffer, and water with fructose (1%) or glucose (1%), as well as in mycelia of old (10-30 days) cultures on different carbon sources. When sugars, alcohols, or amino acids were added to a medium with fructose, NV formation was inhibited, but not completely suppressed. Fructose was shown to be the most potent factor in the appearance of NV.
Asunto(s)
Medios de Cultivo , Variación Genética , Streptomyces/citología , Fructosa/farmacología , Glucosa/farmacología , Glicerol/farmacología , Concentración de Iones de Hidrógeno , Streptomyces/efectos de los fármacos , Streptomyces/genética , AguaRESUMEN
Adifferentiated Nocardia-like variants (Nv) of Streptomyces roseoflavus var. roseofungini, similar in their cultural characteristics with the variant 1-68 described elsewhere (Nikitina, 1968; Kalakoutskii a. Nikitina, 1976), can be obtained not only in the course of growth of the parent culture on a solid medium containing fructose in the form of secondary colonies, but also during submerged cultivation with stirring. Interruptions in aeration do not affect accumulation of the cells of such variants in the medium. A direct correlation has been established between the amount of biomass and the number of Nv colonies when submerged mycelium is inoculated into a solid medium.