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

Abstract

In composting, organic matter is degraded by cellulases and ligninolytic enzymes at temperatures typically above 50 °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 °C, respectively. Maximal cellulase activity was determined as 1.333 mg glucose released ml[superscript −1] min[superscript −1]. Maximal polyphenol oxidase activity attained was 5.111 nmol phenol ml[superscript −1] min[superscript −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.