Aspergillus fumigatus and various other Aspergilli are ubiquitous molds. These are hardy aerobic saprotrophs, growing as easily on breads and potatoes as on plants and trees. However, many Aspergilli are capable of growing in nutrient-deficient or nutrient-absent environments, and surviving in extreme conditions, such as high temperature (up to 55oC) and pH; for example, A. niger, the Black Mold, can grow happily on damp walls. I have observed A. fumigatus grow on the surface of a highly alkaline buffer (pH9; one of the pH meter standards).