NOVELTY - A modified Family 5 cellulase comprising a substitution of an amino acid at position 363 with a non-native alanine, serine, or threonine, where the position is determined from alignment of the modified Family 5 cellulase with amino acids 71-397 of a Trichoderma reesei Cel5A amino acid sequence comprising fully defined 397 amino acids (SEQ ID NO. 1) given in the specification, and where the modified Family 5 cellulase exhibits an increase in specific activity of 1.2-fold relative to a parent Family 5 cellulase or a corresponding wild-type Family 5 cellulase, is new.    USE - The modified Family 5 cellulase is used for bio-stoning and depilling processes (all claimed). The modified Family 5 cellulase is also used for the production of biofuels or biogas. It is used to convert cellulose to glucose, which is subsequently converted to a biofuel or biogas. The glucose is subsequently fermented to a biofuel such as ethanol or butanol or a biogas such as methane. The enzyme mixture containing the modified Family 5 cellulase is also useful for improving the quality of animal feed, where plant material is treated with the enzymes prior to or during the feeding.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) an enzyme mixture comprising one or more cellulases and the modified T. reesei Cel5A enzyme having a substitution of a glycine to an alanine at position 363 as determined by TrCel5A numbering; (2) an enzyme mixture comprising one or more cellulases and the modified T. reesei Cel5A enzyme of SEQ ID NO. 17-19, not defined in the specification; (3) a process for bio-stoning comprises contacting denim fabric or denim garments with the enzyme mixture or the modified Family 5 cellulase; (4) a process for depilling comprises contacting cellulose-containing goods with the enzyme mixture or the modified Family 5 cellulase; (5) a detergent composition comprising the modified Family 5 cellulase; (6) a genetic construct comprising a nucleic acid sequence encoding the modified Family 5 cellulase; (7) a genetically modified microbe comprising the genetic construct; and (8) a process for producing the modified Family 5 cellulase or the enzyme mixture. Sequences not defined here may be found at ftp://ftp.wipo.int/pub/published_pct_sequences/publication.