Saccharomycetes

Saccharomycetes belongs to the kingdom of Fungi and the division Ascomycota. It is the only class in the subdivision Saccharomycotina, the budding yeasts. Saccharomycetes contains a single order: Saccharomycetales.
References.
Saccharomycetes are known for being able to comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as decomposers, feeding on dead and decaying wood, leaves, litter, and other organic matter. According to the article "Phylogenetics of Saccharomycetales,the ascomycete yeasts" the author states "yeasts are responsible for important industrial and biotechnological processes, including baking, brewing and synthesis of recombinant proteins"(Blackwell M). The author also considers saccharomycetes to be model organisms in research. Asia is likely to be the origin of the source.
Reference 
Blackwell, B(2006, NOV 6). Phylogenetics of Saccharomycetales, the ascomycete yeasts. http://apps.webofknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=8&SID=6ALbRzMRklbXdk7UQbm&page=1&doc=6