Black watering can mold
|Black watering can mold|
Microscope image (100x magnification)
Black watering can mold occurs worldwide in the ground and is a common mold on spoiled food in the household. In nature, the fungus attacks various fruits and vegetables such as B. grapes, onions or peanuts, but can also be found in the form of stains on walls or plaster. Flat gray haze on walls is usually attributed to other causes, see black dust .
Metabolic products of the fungus can damage many organic materials , but also cloud the surface of the glass lenses of optical devices (see also glass fungus ). Aspergillus niger forms various mycotoxins such as kojic acid and ochratoxins . The Aspergillus genus can cause a number of health problems.
The mushroom is used in the food industry to produce citric acid . It excretes this acid at low pH values and when there is a lack of iron because the citric acid cycle is disturbed. Black watering can mold is used in food and feed production to produce various enzymes . Aspergillus niger produces a wide range of specific and unspecific cellulases , hemicellulases, glucanases, phytases and proteases under controlled growth conditions . These can be used as a natural alternative to enzymes from genetically modified microorganisms.
The fungus grows at temperatures between 6 and 47 ° C, but best between 35 and 37 ° C. The spores do not survive damp cold at −22 ° C or less. The fungus tolerates pH ranges from 1.5 to 9.8 and is therefore able to exist in both strongly acidic and basic environments.