Genome-Wide Analysis and Expression Profiling of the Cellulase Genes in Aspergillus oryzae

One of the critical steps in lignocellulosic deconstruction is the hydrolysis of cellulose by cellulases. Aspergillus oryzae can produce and secrete a large amount of various extracellular enzymes, including cellulases. However, due to the lack of a comprehensive characterization of the cellulase genes in A. oryzae, the development and application of A. oryzae cellulase are greatly limited. In this study, a total of 219 glycosyl hydrolase genes were systematically identified from the A. oryzae 3.042 genome and classified into 40 glycosyl hydrolase families. Among these glycosyl hydrolase genes, 26 genes encoding the cellulases of endoglucanase, exoglucanase, and β-glucosidase were identified and functionally characterized. The chromosome localizations, gene structures, functional domains, and subcellular localizations of these 26 cellulases were analyzed by bioinformatics. In addition, analysis of the expression patterns revealed that the expression of A. oryzae cellulase genes was time-specific, and most of the cellulase genes were inhibited under low- and high-temperature stress and high salt stress, which had important guiding significance for understanding the transcription patterns of A. oryzae cellulase genes. These findings lay a foundation for our subsequent modification of cellulase activity to realize the industrial applications of A. oryzae cellulase genes in cellulose biorefineries.