NOVELTY - Saccharification (M1) of cellulosic feedstock involves: (A) maintaining a slurry comprising i) a pretreated cellulosic feedstock and ii) endoglucanse under first saccharification conditions for a time sufficient to reduce the yield stress of the slurry; and (B) then combining the slurry with beta-glucosidase and cellobiohydrolase enzymes and maintaining the slurry under second saccharification conditions for a time sufficient to increase the amount of soluble sugars in the slurry.    USE - For saccharification of cellulosic feedstock; for converting a biomass substrate to fermentable sugars (all claimed); in the hydrolysis of biomass feedstock and in the pulp and paper industry; in textile industry; as detergent components, and as additives in animal feeds; for treating textiles for treating pulp or paper; in a cleaning composition e.g. detergent composition; as a feed additive; in industrial application; for producing sugar (e.g. glucose syrups) or biofuels; for textile processing or cleaning e.g. stonewashing, deputing, defuzzing, color clarification, harshness reduction, modifying the texture, feel or appearance of cellulose-containing fabrics or other techniques used during manufacturing or cleaning/reconditioning of cellulose-containing fabrics; in deinking of different recycled papers and paperboards having neutral or alkaline pH, in improving the fiber quality, or increasing the drainage in paper manufacture.    ADVANTAGE - The slurry in step a) is free of cellobiohydrolase and beta-glucosidase activities. The composition is free of beta-glucosidase and cellobiohydrolase enzymes. The variant endoglucanase has improved properties over wild-type endoglucanse; has improved property; and is superior to naturally occurring endoglucanases under conditions required for saccharification of cellulosic feedstock. The method reduces the yield stress of a cellulose-containing mixture by treatment with endoglucanase, followed by treatment with other cellulase enzymes; provides signal peptides that are useful for expression and secretion of heterologous proteins, such as endoglucanses, in host cells, such as Bacillis species.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: 1) a variant endoglucanase polypeptide (v1) comprising: catalytic domain comprising at least 80 (preferably at least 88) % sequence identity to the Streptomyces avermitilis endoglucanase catalytic domain defined in amino acid sequence having 222 amino acids (SEQ ID NO:1) as given in the specification; and an amino acid substitution at a position corresponding to at least one of position Asp1, Ser10, Thr12, Gln14, Gly15, Ala29, Thr33, Asp36, Ser37, Ile41, Gln43, Val48, Thr50, Asn51, Ala53, Val60, Asn68, Ser74, Ala77, Gln78, Leu79, Ser80, Thr81, Val82, Ser83, Tyr91, Ser95, Met98, Ala102, Thr110, Arg118, Ile121, Val131, Ser136, Ala141, Thr142, Gln147, Ser152, Ala165, Ser167, Ser171, Gln182, Val184, Ser185, Gly187, Leu188, Gln190, Asn191, Val198, Pro204, Gln206, Asn207, Thr219 and/or Thr222 in the (SEQ ID NO: 1); 2) a variant endoglucanase polypeptide (v2) comprising a sequence with at least 95% sequence identity to defined amino acid sequence having 222 amino acids (SEQ ID NO: 7) as given in the specification and having an amino acid substitution at any at least one of the following positions Thr12, Val48, Asn68, Gln78, Leu79, Thr81 , Ser152, Ser185, and/or Gln206 in the (SEQ ID NO: 7); 3) an enzyme composition comprising the variant endoglucanase (v1) and (v2); 4) a recombinant polynucleotide encoding the variant endoglucanase polypeptide (v1) and (v2); 5) an expression vector comprising the polynucleotide; 6) a host cell (h1) comprising the polynucleotide; 7) a recombinant host cell that secretes an endoglucanase polypeptide of the variant (v1) and (v2); 8) producing (M2) a variant endoglucanase polypeptide involving: culturing the host cell under conditions sufficient for secretion of the endoglucanase polypeptide by the cell; 9) converting (M3) a biomass substrate to fermentable sugars involving: contacting the variant endoglucanase (v1) and (v2) with the biomass under suitable conditions for the production of fermentable sugars; 10) a fusion protein comprising a first amino acid sequence encoding a signal peptide and second amino acid sequence encoding a heterologous polypeptide, where the first sequence is at the amino terminus of the fusion protein and is defined amino acid sequence having 29 amino acids (SEQ ID NO: 9) as given in the specification and the second sequence does not encode a Bacillus megaterium polypeptide; 11) a recombinant nucleic acid comprising a protein encoding sequence encoding the fusion protein; 12) a recombinant expression vector comprising the nucleic acid; 13) a host cell (h2) comprising the nucleic acid; 14) producing (M4) a heterologous polypeptide in a Bacillus megaterium host cell involving: culturing a host cell (h2) under conditions in which the heterologous protein is secreted; and 15) producing (M5) soluble sugars from a pretreated cellulosic feedstock involving: culturing host cell (h2) under conditions in which the heterologous polypeptide is secreted into a culture medium, where the heterologous polypeptide is a cellulase; and contacting the pretreated cellulosic feedstock with the secreted heterologous polypeptide.