Nutritionally defined conditions for germination of Streptomyces viridochromogenes spores

Abstract

Spores of Streptomyces viridochromogenes were removed from the surface of solid media with glass beads and suspended in a buffer-detergent solution. Addition of yeast extract and glucose resulted in rapid loss of refractility of the spores. Appearance of germ tubes followed. Germination was accompanied by a decrease in the optical density (OD) of the suspension. The OD decrease was used as an assay for germination. A defined germination medium (DGM) comprised of L-alanine, L-glutamic acid, adenosine, para-aminobenzoic acid, and calcium and magnesium ions provided a germination rate nearly equal to that of complex media. The germination rate was essentially the same if i-alanine and D-glutamate replaced the L-isomers. The optimum pH and temperature for germination were 7.0 and 35 C. Germination was absolutely dependent on the presence of CO2. Spores harvested after growth for longer periods than the usual time (10 days) became less germinable in DGM. The same was observed for spores grown at 37 C as compared with 30 C. Spores incubated in DGM for various time periods before being transferred to a buffer solution did not continue to germinate. Spores harvested after growth of eight species of Streptomyces did not show a decrease in OD when incubated in yeast extract medium. Another strain of S. viridochromogenes did exhibit an OD decrease in the medium. Comparative properties of spores of streptomycetes, fungi, and bacilli are discussed.

Streptomyces viridochromogenes spore germination initiated by calcium ions

“…However, the spores did not germinate when incubated with glucose or KCl in the absence of CaCl2 (curves E and F). The amount of absorbance decrease observed with calcium-glucose, calcium-potassium, and calcium-potassium-glucose media was approximately the same as occurs during germination in the previously used defined germination medium (4). Both Sr and Ba ions (0.54 mM) were as effective as Ca ions in initiating germination (data not shown).…”

“…Spores of Streptomyces viridochromogenes germinate when incubated in a defined medium (DGM) comprised of alanine, glutamic acid, adenosine, MgSO4, and CaCl2 (4). The early events in germination, to be referred to as initiation of germination in this paper, involve loss of refractility of the spores accompanied by a decrease in optical density, excretion of spore carbon, increased respiratory activity and ATP content, and release of a germination inhibitor compound (4,6). Germination is dependent on a continual supply of CO2 which serves to replenish tricarboxylic acid intermediates through anaplerotic fixation reactions (2).…”

Consumption of atmospheric hydrogen during the life cycle of soil‐dwelling actinobacteria

“…). No reduction in H 2 uptake stemming from reduced spore viability was expected because the biomass transfer procedure by glass beads is based on established methods for harvesting viable spores (e.g., Hirsch and Ensign, ; Hardisson et al ., ). Furthermore, the number of viable spores in bead‐treated cultures was indistinguishable from the number of viable spores obtained by transferring aerial biomass by a metal spatula from replicate vials incubated at the same time.…”

Sporulation of Streptomyces griseus in submerged culture

“…In most cases, liquid cultures were inoculated with spore suspensions harvested from medium B by the method of Hirsch and Ensign (7), except that the 358 KENDRICK AND ENSIGN spores were suspended and stored in water. The spores were activated by heating in 50 mM Trizma base (Sigma; pH 9.5) at 45°C for 15 min.…”

“…The spores were harvested after incubation at 33°C for 7 days. Aerial spores (from solid cultures) were harvested by the glass bead technique (7); submerged spores (from liquid cultures) were harvested by centrifugation. Microscopic observation revealed that the liquid culture consisted of more than 95% spores; therefore, no precautions were needed to separate the spores from the mycelia.…”