On-Site Enzyme Production by Trichoderma asperellum for the Degradation of Duckweed

The on-site production of cell wall degrading enzymes is an important strategy for the development of sustainable bio-refinery processes. This study concerns the optimization of production of plant cell wall-degrading enzymes produced by Trichoderma asperellum. A comparative secretome analysis was performed on T. asperellum growing on PDA agar, wheat bran and duckweed, respectively. T. asperellum proved to be able to produce a wide enzyme profile, including both depolymerization and debranching enzymes, mainly consisting of hemi-cellulases. The secretome analysis showed specific glycoside hydrolase-induction on duckweed compared with growth on wheat bran and PDA, including a GH62 $-L-arabinofuranosidase, a promising candidate enzyme for the degradation of duckweed. The enzyme cocktail from T. asperellum proved capable of degrading pretreated duckweed, obtaining up to 60% of the theoretical glucose yield, making it a potential candidate for on-site enzyme production.