Yeast Microbe of the Day

Phylum Ascomycetes unicellular fungi typically spherical, oval, cylindrical typical size: 4.3 m x 4 m cell division is by budding or fission most are single cell; can be filamentous facultative aerobes wide habitat: grow where sugars are present reference 1

Saccharomyces most well-known yeast Saccharomyces cerevisiase commercially significant Baker’s/brewer’s yeast model eukaryotic system complete genome sequenced (www.yeastgenome.org)

Commercial Uses CO2 given off by yeasts expands (raises) dough Yeasts ferment sugars to produce alcohol top yeast = ales bottom yeast = lagers sulfur dioxide added to wine to prevent wild type organisms from fermenting reference 2 reference 3 reference 4

Candida yeasts can live on skin surfaces and in the intestinal tracts of warm-blooded animals normal inhabitant filamentous phase is necessary for pathogenicity

Opportunistic Pathogens Candida albicans causes common “yeast infection” Candidiasis of mucous membranes of mouth = “thrush” Can also cause severe diaper rash reference 5 reference 6

References http://www.hirondelle.com/hirondelle/levure-l-hirondelle-2-x-25-g.htm http://www.flickr.com/photos/jasmic/302040475/ http://www.flickr.com/photos/jasmic/302052634/in/set-72157594384506492/ http://photobucket.com/image/beer%20making/cmccalle/Beer%20Making%20101/P2290428.jpg?o=3 http://www.mupeg.com/p_derm_fungal.htm www.tonguethrush.com