| Title | Environmental factors affecting development of Aspergillus nidulans |
|---|---|
| Author | Kap-Hoon Han, Dong-Beom Lee, Jong-Hak Kim, Min-Su Kim, Kyu-Yong Han, Won-Shin Kim, Young-Soon Park, Heui-Baik Kim^1, and Dong-Min Han^2 * |
| Address | Division of Life Sciences, Wonkwang University, Iksan, 570-749, Korea, 1Department of Science Educastion, Seoul National University, Seoul, 151-742, Korea; 2Institute of Basic Natural Science, Wonkwang University, Iksan, 570-749, Korea (Received Nov 6, 2002 / Accepted Jan 10, 2003) |
| Bibliography | Journal of Microbiology, 41(1),34-40, 2003, |
| DOI | |
| Key Words | Aspergillus nidulans, sexual and asexual development, environmental stresses |
| Abstract | Aspergillus nidulans, a homothalic ascomycete, has a complete sexual reproductive cycle as well as an asexual one. Both sexual and asexual development are known to be genetically programmed, but are also strongly affected by environmental factors including nutrients, light, temperature and osmolarity. We have examined these factors to define favored conditions for fruiting body (cleistothecium) formation. In general, fruiting body formation was enhanced where carbon and nitrogen sources were sufficient. Limitation of C-source caused predominant asexual development while inhibiting sexual development. When higher concentrations of glucose were supplied, more cleistothecia were formed. Other carbon sources including lactose, galactose and glycerol made the fungus develop cleistothecia very well, whereas acetate caused asexual sporulation only. Organic nitrogen sources like casein hydrolysate and glycine, and an increase in nitrate or ammonium concentration also enhanced sexual development. In addition to nutrient effects, low levels of aerobic respiration, caused either by platesealing or treatment with various chemicals, favored sexual development. Carbon limitation, light exposure and a high concentration of salts promoted asexual development preferentially, suggesting that stress conditions may drive the cell to develop asexual sporulation while comfortable and wellnourished growth conditions favored sexual development. |
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