Syncephalastrum racemosum
The genus Syncephalastrum is characterised by the formation of cylindrical merosporangia on a terminal swelling of the sporangiophore. Sporangiospores are arranged in a single row within the merosporangia. Syncephalastrum racemosum is the type species of the genus and a potential human pathogen; however, well-documented cases are lacking. It is found mainly from soil and dung in tropical and subtropical regions. It can also be a laboratory aerial contaminant. The sporangiophore and merosporangia of Syncephalastrum species may also be mistaken for an Aspergillus species, if the isolate is not examined carefully.
RG-2 organism
Terminal vesicle, merosporangia and sporangiospores of Syncephalastrum racemosum.
Morphological description:
Colonies are very fast growing, cottony to fluffy, white to light grey, becoming dark grey with the development of sporangia. Sporangiophores are erect, stolon-like, often producing adventitious rhizoids, and show sympodial branching (racemose branching) producing curved lateral branches. The main stalk and branches form terminal, globose to ovoid vesicles which bear finger-like merosporangia directly over their entire surface. At maturity, merosporangia are thin-walled, evanescent and contain five to ten (up to 18) globose to ovoid, smooth-walled sporangiospores (merospores). Maximum growth temperature 40C.
Key features:
Mucorales, producing sympodially branching sporangiophores with terminal vesicles bearing merosporangia.
References:
Domsch et al. (1980), McGinnis (1980), Onions et al. (1981), Rippon (1988), Samson et al. (1995), de Hoog et al. (2000, 2015), Ellis (2005b).
| Antifungal | No | 0.016 | 0.03 | 0.06 | 0.125 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | ≥32 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AMB | 44 | 8 | 16 | 5 | 8 | 7 | |||||||
| ISAV | 4 | 1 | 1 | 2 | |||||||||
| VORI | 9 | 1 | 4 | 4 | |||||||||
| POSA | 45 | 1 | 2 | 6 | 12 | 16 | 5 | 1 | 2 | ||||
| ITRA | 35 | 4 | 3 | 7 | 9 | 9 | 1 | 2 |