Effectiveness of microbial pretreatment by Ceriporiopsis subvermispora on different biomass feedstocks

Different types of feedstocks, including corn stover, wheat straw, soybean straw, switchgrass, and hardwood, were tested to evaluate the effectiveness of fungal pretreatment by Ceriporiopsis subvermispora. After 18-d pretreatment, corn stover, switchgrass, and hardwood were effectively delignified by the fungus through manganese peroxidase and laccase. Correspondingly, glucose yields during enzymatic hydrolysis reached 56.50%, 37.15%, and 24.21%, respectively, which were a 2 to 3-fold increase over those of the raw materials. A further 10–30% increase in glucose yields was observed when pretreatment time extended to 35 d. In contrast, cellulose digestibility of wheat straw and soybean straw was not significantly improved by fungal pretreatment. When external carbon sources and enzyme inducers were added during fungal pretreatment of wheat straw and soybean straw, only glucose and malt extract addition improved cellulose digestibility of wheat straw. The cellulose digestibility of soybean straw was not improved.

► Corn stover, switchgrass, and hardwood were effectively delignified by Ceriporiopsis subvermispora, but wheat straw and soybean straw were not.
► After fungal pretreatment, the glucose yields reached 56.50%, 37.15%, and 24.21% for corn stover, switchgrass, and hardwood, respectively.
► Glucose or malt extract addition improved cellulose digestibility of wheat straw in fungal pretreatment.
► External carbon sources and enzyme inducers addition did not improve the digestibility of soybean straw.
► Fungal degradation by white rot fungi is feedstock selective.