NOVELTY - Isolated or purified polypeptide having an improved endoglucanase (EG) activity as compared to the EG activity of a reference protein EG1, is new, where the polypeptide has e.g. an amino acid sequence of any one of SEQ ID NO: 4 (comprising a fully defined sequence of 442 amino acids as given in the specification), SEQ ID NO: 6 (comprising a fully defined sequence of 445 amino acids as given in the specification) or SEQ ID NO: 8 (comprising a fully defined sequence of 376 amino acids as given in the specification).    USE - The isolated or purified polypeptide is useful in an enzyme composition for hydrolysis of cellulose to produce biofuel (all claimed) including ethanol.    ADVANTAGE - The isolated or purified polypeptide provides the biofuel with improved yield and purity, in a simple and economical manner.    DETAILED DESCRIPTION - Isolated or purified polypeptide having an improved endoglucanase (EG) activity as compared to the EG activity of a reference protein EG1, is new, where the polypeptide has: an amino acid sequence of any one of SEQ ID NO: 4 (comprising a fully defined sequence of 442 amino acids as given in the specification), SEQ ID NO: 6 (comprising a fully defined sequence of 445 amino acids as given in the specification), SEQ ID NO: 8 (comprising a fully defined sequence of 376 amino acids as given in the specification), SEQ ID NOs: 10, 12, 22 and 26 (each comprising a fully defined sequence of 439 amino acids as given in the specification), SEQ ID NOs: 14, 18 and 20 (each comprising a fully defined sequence of 440 amino acids as given in the specification), or SEQ ID NOs: 16 and 24 (each comprising a fully defined sequence of 438 amino acids as given in the specification); or an amino acid sequence having sequence identity of at least 70%, preferably at least 99% to the amino acid sequence of any one of SEQ ID NOs: 4, 6, 8, 10, 12, 14 16, 18, 20, 22, 24 or 26 INDEPENDENT CLAIMS are also included for:    (1) a purified or isolated nucleic acid encoding at least one the polypeptide;    (2) a vector comprising the purified or isolated nucleic acid;    (3) an isolated host cell comprising the nucleic acid or the vector;    (4) an enzyme composition capable of acting on a lignocellulosic biomass and produced by filamentous fungi, comprising at least one of the polypeptide; and    (5) producing a biofuel from a biomass, comprising either: hydrolyzing a lignocellulosic biomass suspended in an aqueous phase in the presence of the enzyme composition to produce a hydrolyzate containing glucose, fermenting the hydrolyzate to produce a fermentation broth, and separating the biofuel from the fermentation broth; or hydrolyzing a lignocellulosic biomass suspended in an aqueous phase, simultaneously adding the enzyme composition and a fermenting organism to produce a fermentation broth, and separating the biofuel from the fermentation broth; or hydrolyzing a lignocellulosic biomass suspended in an aqueous phase, adding at least one host cell with a fermenting organism and/or the enzyme composition to produce a fermentation broth, and separating the biofuel from the fermentation broth.