Consolidated bioprocessing of lignocellulosic biomass to itaconic acid by metabolically engineering Neurospora crassa

Neurospora crassa is a filamentous fungus potent in secreting cellulase and degrading lignocellulosic materials. Here, heterologous cis-aconitic acid decarboxylase was expressed in N. crassa to synthesize itaconic acid which is a high potential platform chemical with applications as an alternative for petroleum-based products. The present study demonstrated that itaconic acid can be produced directly from cellulose and other lignocellulosic materials by the engineered strain, with the highest production of 20.414 +/- 0.674mg/L. The multivariate data analysis methods were used in the parameter analysis of the conversion process. It was found by the hot map analysis that itaconic acid production can promote the secretion of cellulase in N. crassa. Principal component analysis suggested that itaconic acid production was closely related to the concentration of the glucose degraded from lignocelluloses, indicating that the secretion of cellulase is key to the direct conversion of cellulose to itaconic acid in the engineered N. crassa. This work demonstrates that N. crassa could be considered as a new platform in the application of cellulose conversion to itaconic acid.