Characteristics of Cellulolytic Enzymes of Bacillus licheniformis CY-24 Isolated from Button Mushroom Compost

Gyeong-Jin Min1   Hea-sung Park1   Een-ji Lee1   Chan-Jung Lee1,*   

1Mushroom Science Division, National Institute of Horticultural and Herbal Science, RDA, Eumseong 27709, Korea


The present study was performed to improve the technique used for fermenting the mushroom growth medium. Taxonomic analysis of 16S rDNA sequence from the predominant Bacillus strain CY-24 isolated during the fermentation phase of the rice straw medium identified it as Bacillus licheniformis. In addition, the growth environment of B. licheniformis was also examined in this study, which revealed the optimal growth temperature and pH to be 30 ℃ and 6.0, respectively. This study also revealed that carboxymethyl cellulase (CMCase) and polygalacturonase (PGase) enzymes isolated from B. licheniformis achieved their maximal activities at 50 ℃ and 60 ℃ respectively. Furthermore, the study confirmed that the two enzymes, i.e., CMCase and PGase in B. licheniformis are stable at temperatures above 60 ℃. The present study thus demonstrates that B. licheniformis CY-24 possesses excellent enzymatic properties. It also reveals that the action of enzymes during the production of growth mediums used for the cultivation of mushrooms is closely associated with the promotion of fermentation and softening of the rice straw. Overall, this study provides elementary information regarding the role of B. licheniformis enzymes during growth medium fermentation for Agaricus bisporus cultivation.

Figures & Tables

Fig. 1. Phylogenetic tree of Bacillus licheniformis CY-24 based on 16S rRNA sequence similarity. Branching values determined using 1,000 bootstraps. Bar, 1 substitution per 100 nucleotides.