NOVELTY - A biological material comprises an isolated anaerobic thermophilic cellulolytic and xylanolytic bacterium, where the bacterium comprises an endogenous gene having at least 99.9% sequence identity with sequence isolated from Clostridium sp. strain.    USE - As biological material; for conversion of a biomass to bioconversion products (preferably lactic acid, formic acid, acetic acid and/or ethanol or their salts, where the acetic acid/ethanol ratio is at least 13.2); for bioconversion of lignocellulose to fuels, chemicals, protein, silage and biogas.    ADVANTAGE - The Clostridium sp. strain serves as a source of thermostable xylanases and cellulases for industrial applications resulting in increased bioprocessing efficiency and economy. The cellulolytic and xylanolytic strains serve as potential source of previously unknown thermo stable xylanases and cellulases for plant biomass conversion and other industrial applications. The thermophilic organism Clostridium sp. strain contributes significant savings in lignocellulosic biomass to ethanol conversion due to their ability to utilize cellulose, xylose and xylan.    DETAILED DESCRIPTION - A biological material comprises an isolated anaerobic thermophilic cellulolytic and xylanolytic bacterium, where the bacterium (A1) comprises an endogenous gene having at least 99.9% sequence identity with sequence isolated from Clostridium sp. strain (SEQ ID No. 2), not given in specification. INDEPENDENT CLAIMS are included for the following:    (1) conversion of a biomass to bioconversion product involving contacting the biomass with an isolated thermophilic cellulolytic and xylanolytic bacterium, where the bacterium comprises an endogenous gene having at least 99.9% sequence identity with (SEQ ID No: 2);    (2) a transgenic organism comprising a transgene, where the transgene comprises a polynucleotide having at least 80% sequence identity with (SEQ ID No: 4), not given in specification;    (3) new isolated biologically pure culture of an anaerobic thermophilic cellulolytic and xylanolytic bacterium bearing ATCC Deposit No. PTA-10114;    (4) new isolated cellulolytic and xylanolytic bacterium bearing ATCC Deposit No. PTA-10114; and    (5) a protein molecule having at least 95% sequence identity with the enzyme encoded by the polynucleotide sequence of (SEQ ID No: 4).