Hydrothermal pretreatment and fungal degradation to facilitate the enzymatic saccharification of Eucalyptus grandis

Effective pretreatment strategies are warranted to convert lignocellulose to renewable bioenergy to improve the conversion efficiency of enzymatic saccharification. In this study, we combined hydrothermal pretreatment (HTP) with wood-decaying fungal degradation to pretreat Eucalyptus grandis. Chemical composition analysis, X-ray diffraction, Fourier transform-infrared spectroscopy, cross-polarization/magic angle spinning ¹³C nuclear magnetic resonance spectroscopy, and scanning electron microscopy revealed the higher effectiveness of the brown rot fungus Antrodia bambusicola in removing hemicellulose with the aid of HTP. In contrast, the white rot fungus Trametes orientalis exhibited stronger delignification. Enzymatic saccharification analysis revealed a significant increase in the maximum glucose yields of HTP-pretreated E. grandis coupled with A. bambusicola and T. orientalis degradation from 7.19 % to 72.92 % and 77.63 %, respectively. The maximum glucose yield was further optimized to be 97.41 % through Box-Behnken design in response surface methodology. In conclusion, the combined pretreatment strategy of HTP and wood-decaying fungal degradation demonstrates promising performance in enhancing the enzymatic saccharification of E. grandis, further facilitating the broader implications and potential applications in bioenergy manufacturing.