Factors affecting ureolytic activities ofPenicillium waksmanii isolated from sewage sludge |
| |
Authors: | M. A. Ismail S. A. Omar |
| |
Affiliation: | (1) Department of Botany, Faculty of Science, University of Assiut, 71516 Assiut, Egypt |
| |
Abstract: | Twenty one fungal isolates belonging to 7 genera were screened for ureolytic activity. APenicillium waksmanii isolate was found to be the most potent and was selected for further study. No ammonia-nitrogen was detected inP. waksmanii cultures either urea-free or containing up to 1 g urea per L. The maximum extracellular urease production was recorded at a urea concentration of 15 g/L. It peaked after 6 d of incubation at 25°C when the initial pH of the glucose—peptone broth was adjusted to 6. On the other hand, the highest fungus biomass was detected at a concentration of 2 g urea per L after 4 d of incubation at 35°C when the pH of the medium was 8. The intracellular urease activity (measured in cell-free extract) was the highest at 12 mg urea per mL after 75-min incubation at 25°C at pH 8. Incubation temperature of 25°C favored both urease production and activity. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|