Aspergillus flavus

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1. Classification

a. Higher order taxa

Eukaryota; Ascomycota; Eurotiomycetes; Eurotiales; Trichocomaceae

b. Species

Aspergillus flavus

2. Description and significance

Aspergillus flavus is a pathogenic fungus in the phylum Ascomycota. This species is known primarily for its ability to produce a potent toxin and carcinogen known as aflatoxin (1). Aflatoxin is known to contaminate many types of crop seeds, but in the field it is predominantly problematic for maize, peanuts, cotton seed, and tree nuts (1). A. flavus also has a great impact on human health, in which immunosuppressed people are most susceptible to infection by this fungus (1). A. flavus may be found in any type of climate, but it is most common in warm temperate zones and environments with low water levels and higher temperatures (1).

3. Genome structure

The genus Aspergillus consists of 250 recognizable species. These species are further divided into different groups (2). A. flavus is part of the Flavi group, which is notable for its aflatoxin-producing fungi. This section also includes A. parasiticus. The A. flavus genome consists of 37 million base pairs arranged into eight different chromosomes (4). It was found that the genome contains 13,485 predicted protein coding regions, including several secondary metabolite biosynthetic gene clusters (3). Further research on the secondary metabolite biosynthetic gene clusters of this species revealed that there were more than 56 biosynthetic gene clusters (4). The secondary metabolite biosynthetic gene clusters responsible for the production of aflatoxin consists of 25 genes, spanning 70 kb DNA sections located near the telomere of the third chromosome (4).

4. Cell structure

The microscopic characteristics of A. flavus align with the other organisms in the Aspergillus genus. The hyphae of A. flavus are partitioned by a septum and are hyaline, giving them a glossy appearance (2). The organism is a circular vesicle, with protruding filamentous extensions (2). In cell cultures, A. flavus are known to grow as yellow-green colonies and are 65-70 mm in diameter on Czapek yeast extract (1). As the spores mature, they transition into a darker green color (1).

5. Metabolic processes

Describe important sources of energy, electrons, and carbon (i.e. trophy) for the organism/organisms you are focusing on, as well as important molecules it/they synthesize(s).

6. Ecology

Habitat; symbiosis; contributions to the environment.

7. Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

7. Key microorganisms

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8. Current Research

Include information about how this microbe (or related microbes) are currently being studied and for what purpose

9. References

It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page. [Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.