Aspergillus fumigatus- An Overview


Aspergillus is a genus of fungi that consists of hundreds of species that are widely distributed in nature. They are commonly found in soil, plant debris, and indoor air environment. They are filamentous fungi that grow as molds on various substrates and produce spores in the form of conidia.

Aspergillus spp are mostly saprophytic, meaning they obtain their nutrients from dead and decaying organic matter. They produce enzymes such as amylase that break down complex compounds into simple products that can be absorbed by the fungal hyphae. They play an important role in the decomposition of organic materials and the recycling of nutrients in the environment.

Aspergillus spp reproduce asexually by producing conidia on specialized structures called conidiophores. The conidiophores have a swollen vesicle at the tip, which bears flask-shaped or cylindrical cells called phialides. The phialides produce chains of conidia that radiate from the vesicle surface. The conidia are spherical, oval, or elliptical in shape and vary in color depending on the species. The conidia are easily dispersed by air currents and can be inhaled by humans and animals.

Some Aspergillus spp also have a sexual stage, which belongs to the phylum Ascomycota. The sexual stage produces ascospores inside sac-like structures called asci, which are contained in fruiting bodies called cleistothecia. The sexual stage is not common and has been described only for some species of Aspergillus.

Aspergillus spp are important medically and commercially. Some species can cause infections in humans and animals, especially those with weakened immune systems or underlying lung diseases. These infections are collectively called aspergillosis and can range from allergic reactions to invasive and disseminated diseases. Some of the common pathogenic species are Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, and Aspergillus terreus.

Some Aspergillus spp are also useful for industrial and biotechnological purposes. They produce various enzymes, organic acids, pigments, antibiotics, and other metabolites that have applications in food, pharmaceutical, textile, and chemical industries. Some examples of commercially valuable products derived from Aspergillus spp are citric acid, gluconic acid, soy sauce, sake, miso, cheese, penicillin, lovastatin, aflatoxin, and beta-carotene.