Aspergillus Background Information Aspergillus represents a genus of around 200 filamentous fungi made of chains of cells, called hyphae. All Aspergillus species are highly aerobic and grow in oxygen-rich environments worldwide. Most other fungi are usually found growing on carbon-rich surfaces, but Aspergilli can also secrete amylase enzymes, which allow it to use polysaccharides e.g. starch as a carbon source. Several species of Aspergillus also demonstrate oligotrophy, so they are able to grow in environments containing low amounts of nutrients, or even environments in which there is a complete lack of key nutrients. Some Aspergillus species can be pathogenic to humans as well as many grain crops. A. niger, a species of Aspergillus, is as the major source of citric acid, and it accounts for over 99% of global citric acid production in the world.
