Aureobasidium Pullulans
 

 
  
This yeast-like fungus is commonly found on caulk or damp window frames in bathrooms. Aureobasidium (Pullularia) may be pink or black in color. Although it seldom causes infections, it can be allergenic. This is one type of mold that is a type of mildew. It will grow in cooler climates and along with Cladosporium, which is commonly found growing on siding.
 
Pullularia occurs indoors in areas of free water, such as condensate pans, or as a primary colonist of broadloom following a flood. Because its growth form is yeast-like (and are not forcibly discharged), its cells/spores only become airborne through mechanical disruption of contaminated materials or aspiration of contaminated water.
 
Aureobasidium pullulans is not a primary human pathogen nor is it recognized as a producer of significant mycotoxins. High airborne levels of this fungus have been associated with allergic complaints probably due to respiratory irritation mediated by cell-wall components (e. g. beta glucans, glycoproteins), it has also been known as an irritant, and to cause pulmonary problems (small airway).