Enhancement of enzymatic hydrolysis of wheat straw by gamma irradiation–alkaline pretreatment

• Pretreatment of wheat straw by gamma radiation and NaOH was investigated.
• Irradiation pretreatment can significantly decrease NaOH consumption.
• Reducing sugar yield reached 72.67% at 100 kGy and 2% NaOH treatment for 1 h.

Pretreatment of wheat straw with gamma irradiation and NaOH was performed to enhance the enzymatic hydrolysis of wheat straw for production of reducing sugar. The results showed that the irradiation of wheat straw at 50 kGy decreased the yield of reducing sugar, however, the reducing sugar yield increased with increasing dose from 50 kGy to 400 kGy. The irradiation of wheat straw at 100 kGy can significantly decrease NaOH consumption and treatment time. The reducing sugar yield could reach 72.67% after irradiation at 100 kGy and 2% NaOH treatment for 1 h. The combined pretreatment of wheat straw by gamma radiation and NaOH immersion can increase the solubilization of hemicellulose and lignin as well as the accessible surface area for enzyme molecules.