(C1 combination (mg/ml) #1: 0.2 CBH Ia, 0 CBH Ib, 0.2 CBH IIb, 0.08 EG II, 0.02 BGL; #2: 0.2 CBH Ia, 0.2 CBH IIb, 0.07 EG II, 0.02 BGL, 0.01 Xyl II; #3: 0.2 CBH Ia, 0.2 CBH IIb, 0.04 EG II, 0.04 EG V, 0.02 BGL; #4: 0.1 CBH Ia, 0.1 CBH Ib, 0.2 CBH IIb, 0.03 EG II, 0.04 EG V, 0.02 BGL, 0.01 Xyl II.) This showed that the tested mixtures were significantly more effective on this substrate than the ... [Show full abstract] enzyme mixture naturally produced by the C1 strain i.e. the commercial enzyme mixtures (Fig. 2). In general, these type of mixing and matching studies revealed which enzymes were insufficiently present in the ligno-cellulose converting enzyme mixture produced by C1 strains. By means of overexpressing specific C1 genes, these enzyme activities were supplemented resulting in C1 strains that produce optimized enzyme mixtures for efficient saccharification of different types of plant biomass (Fig 3). The availability of a single strain producing the most suitable mix of enzymes allows for cost effective production.