Dactylosporangium

Abstract

Dac.ty.lo.spo.ran'gi.um. Gr. n. daktylos finger; Gr. n. spora a seed, and in biology a spore; Gr. neut. n. angeion (L. translit. angium ) vessel; N.L. neut. n. Dactylosporangium an organism with finger‐shaped, spore‐containing vessels (sporangia). Actinobacteria / Actinobacteria / Micromonosporales / Micromonosporaceae / Dactylosporangium Finger‐shaped to claviform sporangia (0.6–1.4 × 2.5–6.0 µm) are formed on short sporangiophores on the substrate mycelium . They develop singly or in clusters above the surface of the substrate. Each sporangium contains a single row of normally three to four spores . The spores are oblong , ellipsoidal , ovoid , or slightly pyriform (0.4–1.3 × 0.5–1.8 µm) and motile by means of a polarly inserted tuft of flagella. True aerial mycelium is not formed. Hyphae of the substrate mycelium are 0.5–1.0 µm in diameter, branched, and rarely septate. Large single spores, globose bodies (1.7–2.8 µm in diameter) are formed on short branches on substrate mycelium. Organisms are Gram‐stain‐positive and not acid‐fast. The peptidoglycan of the cell walls contains meso ‐ diaminopimelic acid ( meso ‐ DAP ) and glycine , with xylose and arabinose as characteristic sugars of whole‐cell hydrolysates. Colonies grow on various agar media. They are compact, somewhat tough and leathery, and mostly flat or sometimes elevated with a smooth to slightly wrinkled surface. The color of the substrate mycelium is pale orange to deep orange , rose or wine‐colored to brown . Aerobic, chemo‐organotrophic, with optimum growth between 25 and 37°C and at pH 6.0–7.0. DNA G + C content ( mol %): 71–73 ( T m ). Type species : Dactylosporangium aurantiacum Thiemann, Pagani and Beretta 1967, 43 AL .