Background: In this study, phytase-producing bacteria from7 cultivar of rhizosphere wheat (Chamran, Tajan, Morvarid, Pishtaz, Oroum, Sivand, Zarea) were solated and identified based on morphological and biochemical characteristics.
Methods: Enzyme-producing bacteria were determined by production of clear zones around the colonies on the medium containing sodium phytate, after 24-48 h of incubation at 30oC. Because some bacteria in phytase specific medium are able to create false positive results, we eliminated them by phytase plate assay (cobalt chloride, ammonium molybdate / ammonium vanadate). The best phytase producing isolates were recognized by its surrounding clear halo.
Results: Out of 47 colonies on media plates, 19 colonies showed positive for phytase production and created zone of clearing around microbial colonies, but 11 false positive colonies were detected. Finally, 8 isolates were detected as real phytase-producing bacteria. Most isolated bacteria belong to two cultivars (Tajan, Chamran). One strain creating 23 mm zone was selected as the best enzyme producing isolate.
Conclusion: This research provided important data about phytase producing bacteria isolated from rhizosphere wheat, which will facilitate future research on the optimization of fermentatoin processes for production of high phytase activity.