On the way towards the understanding of suberin degradation by Aspergillus nidulans

Dissertation presented to obtain the Ph.D degree in Biochemistry.

Filamentous fungi ensure major recyclability cycles on Earth. Two tons of plant material are deposited per year and per hectare (average in temperate zones), of which biopolyesters are the third most abundant of the major plant polymers. Suberin, a complex aromatic-aliphatic cross-linked biopolyester, is a structural component of the plant cell wall. It builds an inner barrier which is ingrained between a primary and a tertiary cell wall (i.e. between a lignocellulose layer and a polysaccharide one, respectively). The suberin barrier is virtually impermeable to water and solutes and protects the plant from numerous biotic and abiotic stresses. It is thought to physically strengthen the cell wall, protecting it from microbial hydrolysis, and to exhibit antimicrobial properties. Hence, biopolyester degradation by filamentous fungi (in particular by Ascomycota strains - preliminary demonstrated in few studies) should be further considered.(...)