Abstract—Aspergillus niger, Aspergillus flavus, and Rhizopus oryzae are common filamentous fungi found in food, agriculture, and the environment. They play important roles in industrial production, food safety, and fermentation. Previous studies have mainly focused on metabolism, toxin production, or industrial applications of individual fungal species. In contrast, systematic comparative studies of the morphology and growth characteristics of these three molds remain limited. In this study, three standard strains were grown on PDA medium and evaluated using colony observation, microscopic examination, measurement of growth extent, and temperature adaptability tests. We compared their colony shape, microscopic structures, growth extent, and temperature adaptability. The results showed differences in colony shape, hyphal structure, and reproductive structures among the three species. These features are useful for fungal identification. Rhizopus oryzae grew the fastest, followed by Aspergillus flavus and Aspergillus niger. Among the three temperatures tested, all three fungi grew best at 28 °C. However, Aspergillus niger showed more tolerance to higher temperatures, Rhizopus oryzae showed better growth at lower temperatures, and Aspergillus flavus showed balanced adaptability to the environment. This study aimed to offer practical support for fungal identification and microbiology teaching.
 
Keywords—Aspergillus niger, Aspergillus flavus, Rhizopus oryzae, morphology, growth characteristics

Cite: Xingjian Duo, "Comparative Study on the Morphological and Growth Characteristics of Aspergillus niger, Aspergillus flavus, and Rhizopus oryzae," International Journal of Pharma Medicine and Biological Sciences, Vol. 15, No. 4, pp. 167-170, 2026.

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