2.4. Identification of the phytase producing fungal isolate
The phytase producing fungal isolate was identified by microscopic examination, the mycelium and conidiophores were observed after cultured on concavity slide with PDA medium at 28 C and then colored by fungus staining solution (20.0 g phenol, 20.0 ml lactic acid , 40.0 ml glycerin, 20 ml distilled water and 0.05 g cotton blue). Furthermore, the 18S rDNA was amplified by polymerase chain reaction (PCR) using primers designed to amplify 1500 bp fragment of the 18S rDNA
region. The forward primer was 18SF149:50-GGAAGGG (G/A) TGTATTTATTAG -3 and the reverse primer was 18SR 701: 50-GTAAAAGTCCTGGTTCCC-30 After full identification, the fungus isolate was deposited in NRC culture collection under the name P. purpurogenum GE1. The fungal identification was carried out at City for Scientific Research, New Borg El-Arab City, Alexandria, Egypt.