Cellulases (CMCases) and polyphenol oxidases from thermophilic Bacillus spp. isolated from compost

In composting, organic matter is degraded by cellulases and ligninolytic enzymes at temperatures typically above 50 degrees C. This study isolated thermophilic microorganisms from a compost system that were then screened for cellulase and polyphenol oxidase activity. Temperature optima for the cellulases and polyphenol oxidases were determined as 70 and 40 degrees C, respectively. Maximal cellulase activity was determined as 1.333 mg glucose released ml(-1) min(-1). Maximal polyphenol oxidase activity attained was 5.111 nmol phenol ml(-1) min(-1). Cellulases were found to be stable over a period of 1 h. The isolated compost microorganisms were identified as strains of Bacillus using 16S ribosomal DNA sequence analysis. (c) 2006 Elsevier Ltd. All rights reserved.