The main difference between Aspergillus niger and Aspergillus flavus is that A. niger grows within soil and water, on vegetation, decomposing matter, and suspended in the air, whereas A. flavus occurs in colonies in legumes, cereal grains, and tree nuts.
A. niger and A. flavus are two Aspergillus species that belong to the family Trichocomaceae. Its asexual spore-forming structure is characteristic.
Key Areas Covered
1. What is Aspergillus Niger
– Definition, Characteristics, Importance
2. What is Aspergillus Flavus
– Definition, Characteristics, Importance
3. Similarities Between Aspergillus Niger and Aspergillus Flavus
– Outline of Common Features
4. Difference Between Aspergillus Niger and Aspergillus Flavus
– Comparison of Key Differences
Key Terms
Aspergillus Flavus, Aspergillus Niger
What is Aspergillus Niger
A. niger is a species of the genus Aspergillus. Also, it is a mold that occurs commonly in nature. It occurs in the soil, water, suspended air, vegetation, and decomposing matter. Especially the species rapidly grow and form spores during a few days of germination. However, the characteristics unique to A. niger make the species invaluable for producing metabolites in biotechnological approaches. These characteristics include a high metabolic rate, high production yield, secretion capability, conducting post-translational modifications, and producing secondary metabolites at higher rates. Also, the fungus is capable of withstanding extremely acidic environments.
Figure 1: A. niger
Furthermore, A. niger cause ‘black mold’ disease in certain fruits and vegetables like apricot, grapes, onion, and peanuts. Also, it is a common contaminant of food. It is more common in indoor environments as well. However, the FDA graded it as Generally Recognized as Safe (GRAS). But it may produce toxins that can affect human health.
What is Aspergillus Flavus
A. flavus is another species of the genus Aspergillus. It is both a saprophytic and pathogenic fungus. It especially forms colonies in legumes, cereal grains, and tree nuts. Therefore, it is responsible for the postharvest rot during harvest, storage, and transit. It causes ear rot in corn. Also, it causes yellow mold in peanuts. Postharvest rot produces toxins called mycotoxins that are toxic to mammals. Additionally, it causes infections in crops that are not visible in the harvest. It infects seedlings by sporulation. The frequently observed color of spores of A. flavus is yellow. Thereby, it gains its name.
Figure 2: A. flavus
Moreover, A. flavus is an opportunistic pathogen in humans and animals. Also, it causes aspergillosis in immunocompromised individuals.
Similarities Between Aspergillus Niger and Aspergillus flavus
- A. niger and A. flavus are two species of Aspergillus.
- They belong to the family Trichocomaceae.
- They are molds that occur in various climates.
- Both can be pathogenic.
Difference Between Aspergillus Niger and Aspergillus flavus
Definition
A. niger refers to a type of mold that can sometimes cause some cases of pneumonia, while A. flavus refers to a saprotrophic and pathogenic fungus with a cosmopolitan distribution.
Conidiospores
The conidiospores of A. niger are long and smooth, while the conidiospores of A. flavus are variable in length, rough, pitted, and spiny.
Phialides
The phialides of A. niger are biseriate and form a radiate head, while the phialides of A. flavus are uniseriate and biseriate, pointing in all directions.
Macroscopic Morphology
A. niger forms wooly colonies that are white to yellow, while A. flavus forms velvety colonies that are yellow to green or brown.
Conclusion
In brief, A. niger and A. flavus are two Aspergillus species that form molds. They belong to the family Trichocomaceae. A. niger includes long and smooth conidiospores. The phialides of A. niger are biseriate and form a radiate head. The colonies of A. niger are wooly and white to yellow. In comparison, A. flavus forms conidiospores that are various in length. They are also rough, pitted, and spiny. The colonies of A. flavus are velvety and yellow to green in color. Therefore, their morphology is the main difference between A. niger and A. flavus.
References:
- Aspergillus species. Share and Discover Knowledge on SlideShare. (n.d.). https://www.slideshare.net/SafinaKouser/aspergillus-spp-61041295
Image Courtesy:
- “Aspergillus niger 01” By Rasbak – Own work (Public Domain) via Commons Wikimedia
- “Aspergillus flavus” By Medmyco – Own Work (CC-BY SA 4.0) via Commons Wikimedia
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