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Two genes encoding lytic polysaccharide monooxygenases (LPMOs) CsLPMO9A and CsLPMO9B were cloned from the white-rot fungus Ceriporiopsis subvermispora and successfully expressed in Komagataella phaffii. The oxidative degradation of phosphoric acid swollen cellulose by the LPMOs was conducted using ascorbic acid as an electron donor. Analysis with high performance anion-exchange chromatography and matrix assisted laser desorption/ionization-time-of-flight mass spectrometry indicated that the two enzymes cleaved the polysaccharides by oxidization of the C1 carbon atom of the glucose unit. Synergistic effects between CsLPMO9A or CsLPMO9B and a commercial cellulase cocktail from Trichoderma reesei were observed in the saccharification of delignified wheat straw. The amounts of glucose, cellobiose and xylose released from the substrate by the combined enzymes were increased by 83 %, 16 % and 47 % (for CsLPMO9A), or 79 %, 52 % and 81 % (for CsLPMO9B), compared to the cellulase alone, respectively. The two new enzymes displayed promising potential in industrial bioconversion of lignocellulosic biomass.

AIMS To characterize the hemicellulolytic and cellulolytic enzymes from novel fungi, and evaluate the potential of novel enzyme system in releasing ferulic acid (FA) from biomass resource. METHODS AND RESULTS A hemicellulolytic and cellulolytic enzyme-producing fungus 4-14 was isolated from soil by Congo red staining method, and identified as Eupenicillium parvum based on the morphologic and molecular phylogenetic analysis. The optimum temperature of fungal growth was 37°C. Hemicellulolytic and cellulolytic enzymes were produced by this fungus in solid-state fermentation (SSF), and their maximum activities were 554, 385, 218, 2·62 and 5·25 U g(-1) for CMCase, xylanase, β-glucosidase, FPase and FAE respectively. These enzymes displayed the best catalytic ability at low pH values (pH 4·5-5·0). The optimum temperatures were 70°C, 70°C, 75°C and 55°C for CMCase, β-glucosidase, xylanase and FAE respectively. CMCase, xylanase and FAE were stable at different pHs or high temperature (60°C). Enzymatic hydrolysis experiment indicated that the maximum (76·8 ± 4)% of total alkali-extractable FA was released from de-starched wheat bran by the fungal enzyme system. CONCLUSIONS High activities of thermotolerant CMCase, β-glucosidase, xylanase and FAE were produced by the newly isolated fungus E. parvum 4-14 in SSF. The fungal enzyme system displayed high efficiency at releasing FA from wheat bran. SIGNIFICANCE AND IMPACT OF THE STUDY This study provides a new fungal strain for researches of novel hemicellulolytic and cellulolytic enzymes and will improve the bioconversion and utilization of agricultural by-products.