Schizosaccharomyces
The fission yeast ( Schizosaccharomyces ) are a fairly systematically standing isolated genus of Ascomycota, which alone forms the class Schizosaccharomycetes. The species live as Saprobionten in sugary exudates of plants.
Features
A mycelium is not formed or is poorly developed. It is not formed Askokarp, no tissue between the asci. The vegetative cells are cylindrical, and reproduce by simple cell division, two identical daughter cells. From this type of cell division, the name " fission yeasts " comes because the other yeasts ( Saccharomycetes ) reproduce by budding.
Sexual reproduction begins with the fusion of two vegetative cells to an ascus. This is followed by karyogamy and meiosis. The resulting four nuclei can divide one more time, so be at the end of four or eight ascospores. However, after plasmogamy the fission yeasts can multiply as dikaryotic cells.
System
The genus forms a separate class within the Taphrinomycotina.
There are at least two dozen species: A selection:
- Schizosaccharomyces japonicus
- Schizosaccharomyces kambucha
- Schizosaccharomyces octosporus
- Schizosaccharomyces pombe