Assessment of the structural factors controlling the enzymatic saccharification of rice straw cellulose

•The factors governing the enzymatic hydrolysis of rice straw cellulose were verified.•The cellulose surface area of rice straw governs the initial reaction rate.•The long-term cellulose conversion is largely affected by the lignin removal rate.•Silica is not the crucial factor controlling the enzymatic saccharification.

In this study, the structural factors controlling the enzymatic saccharification of rice straw cellulose were examined by preparing structure-modified rice straw samples such as dewaxed, alkali-treated, oxidized, and swollen rice straw. It was found that the initial enzymatic saccharification rate of the various structure-modified samples was largely controlled by the initial cellulose surface area of the cellulose unit. Although the presence of lignin limited the cellulose surface area, there was no strong relationship between the lignin content and the initial reaction. On the other hand, the long-term enzymatic saccharification of rice straw cellulose highly depended on the lignin removal rate (lignin content). It was also found that silica is not a crucial factor in controlling the enzymatic saccharification.