Aspergillus niger is a common fungus found in various environments, including soil, decaying plant matter, and indoor spaces. It appears as a black mold and is known for its ability to thrive in diverse conditions, making it a significant organism in both nature and industry. This fungus is widely used in biotechnology, particularly in the production of enzymes and organic acids, such as citric acid. While Aspergillus niger is generally safe, it can produce mycotoxins that may pose health risks, especially in individuals with weakened immune systems or respiratory issues.