Novel Industrial Applications of Aspergillus oryzae Genomics
Keietsu Abe, Kentaro Furukawa, Tomonori Fujioka, Daisuke Hagiwara, Hiroshi Maeda, Jun-ichiro Marui, Osamu Mizutani, Toru Takahashi, Akira Yoshimi, Youhei Yamagata, Katsuya Gomi, and Fumihiko Hasegawa
from: Aspergillus: Molecular Biology and Genomics (Edited by: Masayuki Machida and Katsuya Gomi). Caister Academic Press, U.K. (2010)
The Aspergillus fungi include the industrial fungi A. oryzae and A. niger, a human pathogen A. fumigatus, an aflatoxin producer A. flavus, and the model fungus A. nidulans. Because these fungi are important from industrial, medical, and agricultural standpoints, their genome sequences have been determined. After or during the course of their genome sequencing projects, genomic tools such as DNA microarrays for each species and efficient gene targeting methods have been developed. The genomic tools are now available to support functional genomic analysis of each fungus and for discovering industrially, medically, and scientifically important genes in combination with bioinformatics and genomic information. This review describes three examples of novel industrial approaches to using A. oryzae genome information and DNA microarrays. (i) A. oryzae DNA microarrays have been used to monitor solid-state fermentation, and transcriptome analyses of the process have revealed how A. oryzae produces large amounts and a large variety of hydrolytic enzymes. (ii) A. oryzae DNA microarrays were used as discovery tools to screen novel proteins that can promote the degradation of biodegradable plastics in combination with hydrolytic enzymes. As a result of this screening, a hydrophobin protein (RolA) and a novel surfactant protein (HsbA) were found. The two proteins can bind tightly to the solid surface of plastics, and subsequently recruit a polyesterase (cutinase) onto the solid (plastic surface)?liquid interface to promote enzymatic hydrolysis of the plastics. (iii) DNA microarrays for Aspergillus spp. have been used in functional genomics studies of signal transduction pathways. Some pathway-specific target genes have been assigned by means of transcriptome analyses, and pathway-specific reporters have been constructed from the promoters of the target genes for use in screening antifungal drugs.