OICC Press International Journal of Recycling of Organic Waste in Agriculture 2251-7715 7 4 2018 09 08 Utilization of wheat straw for fungal phytase production 10.1007/s40093-018-0220-z EN Zohre Shahryari Department of Chemical and Polymer Engineering, Faculty of Engineering, Yazd University, Yazd, Iran Mohammad H. Fazaelipoor School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran Payam Setoodeh School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran Ramkumar B. Nair Swedish Centre for Resource Recovery, University of Boras, 50190 Borås, Sweden Mohammad J. Taherzadeh Swedish Centre for Resource Recovery, University of Boras, 50190 Borås, Sweden Younes Ghasemi Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran Journal Article 2018 09 08 Purpose Wheat straw is an agricultural waste which can be used as a cost effective animal feed. However, high hemicelluloseand phytic acid content in wheat straw prevents it as a primary feed choice. Utilization of wheat straw in solid-statefermentation may result in wheat straw valorization and enzyme production. In this study, phytase production in solid-statefermentation of wheat straw using Aspergillus ficuum and valorization of wheat straw were evaluated.Methods A two-step experimental design procedure was employed for screening and optimization of influencing factorson phytase production. Effects of different nutritional and environmental factors were investigated by one factor at the timemethod (OFATM). To reach higher amounts of phytase, response surface methodology (RSM) was employed to optimizephytase production as a function of three of the most effective factors.Results Optimization of the significant parameters resulted in an increase in the phytase activity from 0.74 ± 0.12 to a maximumof 16.46 ± 0.56 Units per gram dry substrate (U gds−1). The high degree of the fungal phytase activity on wheat strawresulted in the decrease in phytic acid content by 57.4%, as compared to the untreated sample. Scanning electron microscopy(SEM) and FTIR structural analysis showed intensive fungal growth on wheat straw, and partial removal of hemicelluloses,lignin and phytic acid.Conclusion The study demonstrated the feasibility of wheat straw utilization in solid-state fermentation using Aspergillusficuum toward the production of phytase and valorization of wheat straw as an animal feed.