Improved enzymatic hydrolysis of wheat straw by combined use of gamma ray and dilute acid for bioethanol production

•The glucose yield was significantly affected by combined pretreatment.•Increasing enzymatic hydrolysis is due to decrease in their structures.•Combined pretreatment is the most effective method for the enzymatic hydrolysis.

Pretreating wheat straw with a combination of dilute acid and gamma irradiation was performed in an attempt to enhance the enzymatic hydrolysis for bioethanol production. The glucose yield was significantly affected by combined pretreatment (3% sulfuric acid-gamma irradiation), compared with untreated wheat straw and individual pretreatment. The increasing enzymatic hydrolysis after combined pretreatment is resulting from decrease in crystallinity of cellulose, loss of hemicelluloses, and removal or modification of lignin. Therefore, combined pretreatment is one of the most effective methods for enhancing the enzymatic hydrolysis of wheat straw biomass.