3. Results and discussion 3.1. Screening for phytase enzyme producing microorganisms The phytase producing isolates were screened on a medium containing 5% calcium phytate as the sole carbon source. Ten bacterial and four fungus colonies were picked on the basis of the clearing zones around the colonies. Secondary screening on liquid medium was achieved to choose only the potential phytase producer. Among, 5 fungal isolates the fungus coded GE1 showed maximum phytase productivity (150 U/ml) (data not shown). Accordingly, this isolate was chosen for further investigations. 3.2. Fungal Isolate identification The phytase producing fungus isolate was identified as P. purpurogenum by both microscopic examination and DNA sequence, Therefore it was designated as P. purpurogenum GE1. 3.3. Evaluation of different substrates for phytase production This work was started by evaluating the production of phytase by using different agro industrial wastes. The results in Fig. 1 showed that all the used substrates had phytase activity despite variation in the degree of activity. Maximum enzyme productivity (46 ± 2.8 U/g ds) was achieved with corn cope, followed by corn bran (41 ± 4.2 U/g ds) while the minimum productivity (8 U/g ds) was noticed with sesame oil cake as substrate/ support material. Furthermore, combination between corn cobs and corn bran with different concentrations to enhance the phytase production was tested. The results in Fig. 2 showed that the best concentration was reached at 2.5:2.5 (w/w) ratios. This combination enhanced the enzyme production up to (57 ± 3.5 U/g ds); hence mixed substrate was used for further studies. Fungi are considered the better adapted organisms for SSF, since their hyphae could grow on the surface of particles and are also able to penetrate through the inter particle spaces, and then colonized it (Santos et al. 2004). Using of waste products in solid state fermentation became a main goal of many authors, to get cheap medium and solve the problems resulted from the accumulation of these wastes. Within this context, the isolate was cultivated on different agro-residues waste