RESEARCH ARTICLE Analysis of Genomic Regions of Trichoderma harzianum IOC-3844 Related to Biomass Degradation

Trichoderma harzianum IOC-3844 secretes high levels of cellulolytic-active enzymes and is therefore a promising strain for use in biotechnological applications in second-generation bioethanol production. However, the T. harzianum biomass degradation mechanism has not been well explored at the genetic level. The present work investigates six genomic re-gions (~150 kbp each) in this fungus that are enriched with genes related to biomass con-version. A BAC library consisting of 5,760 clones was constructed, with an average insert length of 90 kbp. The assembled BAC sequences revealed 232 predicted genes, 31.5 % of which were related to catabolic pathways, including those involved in biomass degradation. An expression profile analysis based on RNA-Seq data demonstrated that putative regula-tory elements, such as membrane transport proteins and transcription factors, are located in the same genomic regions as genes related to carbohydrate metabolism and exhibit simi-lar expression profiles. Thus, we demonstrate a rapid and efficient tool that focuses on spe-cific genomic regions by combining a BAC library with transcriptomic data. This is the first BAC-based structural genomic study of the cellulolytic fungus T. harzianum, and its findings provide new perspectives regarding the use of this species in biomass degradation processes