Method and dna constructs for increasing the production level of carbohydrate degrading enzymes in filamentous fungi

Abstract

The invention is related to a method and DNA constructs for obtaining in a filamentous fungus host a higher production level of a carbohydrate degrading (CD) enzyme, having in its original state a catalytic module (CAT) and a carbohydrate binding module (CBM) separated by a linker region. The DNA construct comprising a truncated actinomycetes, preferably(NJ) derived DNA sequence encoding a truncated form of the CD enzyme, for example Nf Xyn11A, Nf Xyn10A, and is introduced into a filamentous fungal host. Said CD enzyme contains the catalytically active region of CAT but lacks part or all of the CBM, or all of the CBM and part or all of the linker region and is expressed and secreted under the control of regulatory sequences comprising at least a signal sequence, but also promoters, terminators and DNA sequences encoding a secretable carrier protein or domains thereof, preferably originating from filamentous fungi are included. The production level obtained with DNA sequence having the shortened DNA sequence encoding the truncated form of the CD enzyme is higher than the production level obtained with DNA construct encoding the corresponding full length CD enzyme.