Aureobasidium melanogenum

Aureobasidium melanogenum, formerly known as Aureobasidium pullulans var. melanogenum is a ubiquitous black, yeast-like fungus that is found mainly in freshwater habitats. The species also includes strains causing human infections, which were previously classified as A. pullulans. It was named due to abundant melanin production and accumulation in the cell walls, which leads to dark green, brown or black appearance of the cells and colonies The species was established when the genomes of the four former varieties of Aureobasidium pullulans were sequenced and the large differences between them were discovered. The species tolerates up to 10% of NaCl and grows between 10 °C and 35 °C. Colonies on malt extract agar on average grow to 25 mm in 7 days (at 25 °C), appearing smooth and slimy due to abundant sporulation and EPS formation. In two weeks the colonies become green to black due to the production of melanin. Melanin is produced during the production of pullulan, a polysaccharide par......read more on Wikipedia.