Characteristics of spores formed by surface and submerged cultures of Streptomyces albidoflavus SMF301

Abstract

Stveptomyces albidoflavus SMF301 produced abundant spores in submerged cultures (submerged spores) as well as on solid media (aerial spores). The content of carbon, hydrogen, nitrogen, and phosphorus in submerged and aerial spores was similar; however, the contents of metal ions (K+, Na+, Ca2+ and Mg2+) were very different. Glutamic acid, alanine, and glycine, all known to be cell-wall components, were the major amino acids in both types of spores. However, cysteine was more abundant in submerged spores than in aerial spores. The major fatty acid in aerial spores was n-C,, (61.74%), whereas in submerged spores it was ai-C,, (33.68%). The contents of ai-C,,, and ai-C,, in submerged spores were also very much higher than in aerial spores. Unsaturated fatty acids were found in both kinds of spores but not in mycelium; they were particularly abundant in submerged spores. The composition of menaquinones in the two kinds of spores also varied. The resistance of aerial spores to lysozyme digestion, mild acid treatment, heating and desiccation was higher than that of submerged spores, but the submerged spores were more resistant to sonication.

Mycelium differentiation and development of Streptomyces coelicolor in lab-scale bioreactors: Programmed cell death, differentiation, and lysis are closely linked to undecylprodigiosin and actinorhodin production

“…S1H), were observed. Further work will be necessary to characterize if these round segments present the resistance properties characterizing Streptomyces spores formed in solid cultures (Lee and Rho, 1993).…”

ArgR of Streptomyces coelicolor Is a Pleiotropic Transcriptional Regulator: Effect on the Transcriptome, Antibiotic Production, and Differentiation in Liquid Cultures

“…Microscopy analysis displayed the division and separation of nucleoids and the physical strangulation of hypha, forming chains of individual round segments in mutant liquid cultures, two principal events associated with sporulation (Figure 7 ). While sporulation in liquid cultures has occasionally been described in other Streptomyces strains (Lee and Rho, 1993 ; Rho and Lee, 1994 ; Rueda et al, 2001 ), in S. coelicolor it is very unusual and has only been reported in flask cultures submitted to either nutritional downshift or Ca 2+ supplementation (Daza et al, 1989 ), in S. coelicolor strains overexpressing ssgA (van Wezel et al, 2000a ), and recently, in 2-L bioreactors (Rioseras et al, 2014 ). The signals triggering sporulation in Streptomyces hyphae (the upper parts of the aerial mycelia in solid cultures; the border of the mycelial pellets in liquid cultures) remain poorly characterized.…”

Secondary Metabolites Produced during the Germination of Streptomyces coelicolor

“…Moreover, if albaflavenone was incorporated into the hydrophobic envelope of spores, as other terpenoids do incorporate into the lipophilic membrane layers, it would affect the permeability of the envelopes leading to an intense water influx into spores, thereby accelerating their germination. If we reason that the thickness of the hydrophobic spore envelope is not unified (Lee and Rho, 1993 ), then the water influx comes into different spores in a different intensity, and therefore, naturally, germination is a non-synchronous process (Hirsch and Ensign, 1976a ; Xu and Vetsigian, 2017 ). The spores already germinated would produce albaflavenone as a signal that environmental conditions are appropriate for the growth of the whole population.…”