In the current study, the effect of fumigation with three doses (3, 5 and 7 g/ton) of phosphine (PH3) on wheat grains sustained at 10% and 14% moisture content (MC) for 6 months was evaluated. At the 10 % MC, percentage of germination and speed of germination index (SGI) of wheat grains as well as the average length of the shoot and primary root of seedlings showed marked increase in response to PH3 treatment compared to control (non-fumigated grains). On the other hand, the percentage of abnormal seedlings decreased with the increase in PH3 doses. Nearly similar effects of PH3 were observed on wheat grains and seedlings kept at 14% MC. Four fungal isolates expected to be new records on wheat grains were diagnosed on both morphological and molecular bases. Phylogenetic analyses revealed that two strains were classified as Alternaria ventricosa AUMC 14510 (MT974152) and Cladosporium allicinum AUMC 14511 (MT974153), which recorded here for the first time in Egypt. The other two strains showed lower similarity with related species in the GenBank and were described as potentially new species assigned as Bipolaris sp. AUMC 14512 (MT974154) and Alternaria sp. AUMC 14513 (MT974155). The amylolytic, cellulolytic and xylanolytic activities of these fungi were assayed in submerged fermentation. A. ventricosa and Alternaria sp. were the highest amylase producers registering specific activities of 65.5 IU/mg and 75.7 IU/mg respectively. C. allicinum was superior in the production of endoglucanase, exoglucanase and xylanase gaining 93.1 IU/ml, 64.46 IU/ml and 23.9 IU/ml for the three enzymes respectively.