”Aspergillus niger” FM-32, an isolate from agricultural soil, which was detected for molecular characterization by 18S rRNA gene sequence. This strain was evaluated for production of extracellular phytase in medium containing various agricultural residues: wheat bran, maize bran, rice bran and rice husk under submerged fermentation conditions (SmF). The culture conditions were optimized for maximum enzyme production. The maximum production of phytase by this isolated was obtained on thirteenth day. The best carbon and nitrogen sources for maximum phytase production were 1% mannitol and 1% yeast extract, respectively. The enzyme optimal pH was found to be 5.0. The optimal temperature for enzyme activity was found to be 40 οC. Furthermore, inoculum amount 2% (v/v) of spore suspension (5 × 106 spores/ml) and agitation rate 150 rpm was found.
As a result, maximum phytase activity was found 459 U/ml in rice medium. Thus, phytase can be a potential candidate in animal nutrition due to its high activity and stability.