Genome characterization of the sugarcane-associated fungus Trichoderma ghanense CCMA-1212 and their application in lignocellulose bioconversion

Trichoderma spp. are producers of cellulolytic enzymes for industrial applications. The taxonomy of Trichoderma has been revised, and more than 100 species are known, many of which have superior capacity of production of cellulases in comparison with industrial strains. Saccharum officinarum is one of the main crops in Brazil, mainly due to the production of biofuels. The bioconversion of lignocellulosic biomass to ethanol and renewable chemicals can be achieved by using fungi capable of producing enzymes in high concentrations and grown on low cost substrates. The biotechnological potential of sugarcane-associated fungi has been little explored, especially regarding the production of enzymes. We screened 420 native strains of Trichoderma spp. isolated from rhizospheric soil of sugarcane cultivated in Brazil. One strain (CCMA-1212) was selected because it showed activity of total cellulases and laccases significantly superior to the industrial bioconversion fungus, T reesei Rut-C30, when grown on filter paper, delignified, and non-delignified pretreated sugarcane bagasse. Their enzymes were investigated for enzymatic saccharification of pretreated bagasse. We identified the CCMA-1212 as T. ghanense and sequenced their genome in an Illumina-based whole-genome shotgun combined with mate-pair sequencig approach. The acquired sequence reads were assembled into 50 scaffolds with N50 of 1.9 Mb. The resulting genome sequence has an estimated size of 31.7 Mb with a G+C content of 54%. The sctructural annotation yelded 10685 genes with 63.8% containing PFAM domains and 847 potentially secreted proteins. All of these efforts provide guidance for the better application of T. ghanense in lignocellulose bioconversion. The data confirm the hypothesis that sugarcane-associated fungi are a promising source of new strains with biotechnological potential, and that among the best selected strains are Trichoderma species that have not been exploited for industrial lignocellulose bioconversion. T. ghanense CCMA-1212 can be considered an alternative to T. reesei for the biomass saccharification process.