Twenty six microorganisms were isolated from Iowan soil and horse manures and screened to test their cellulolytic activity. Plate count agar containing 1% (w/v) carboxymethyl cellulose (CMC) or oat spelt xylan instead of glucose was cultivated at 35 or 50°C. The cellulase and xylanase activities of bacterial strains were then tested using 1% (w/v) CMC or oat spelt xylan as substrates and measuring the concentration of reducing sugar by DNS method. It was found that they were all rod shape and gram positive strains. Among them, BEL-Kim-S3-1 and BEL-Kim-M6 strains have shown the highest performance in terms of cellulase and xylanase activities, respectively. The maximum cellulase and xylanase activities of 119.8 and 7054.4 IU were measured after growth of the strains with 1% (w/v) CMC at 35°C for 5 days and with oat spelt xylan at 35°C for 6 days, respectively. These selected strains were further tested with ammonia pretreated corn stover for the production of sugars and ethanol.