KOREASCHOLAR

The mannanase-producing bacteria, designated YJ17, was isolated from spent mushroom (Flammulina velutipes) substrates. The isolate YJ17 was a facultative anaerobic and was grown at temperatures ranging from 20oC to 50oC with an optimal temperature of 40oC. The DNA G+C content of the YJ17 was 44 mol%. The major fatty acids were anteiso-15:0 (38.9%), 17:0 (7.6%), and iso-15:0 (36.5%). The 16S rRNA gene sequence similarity between the isolate YJ17 and other Bacillus strains was from 98% to 99%. In the phylogenetic analysis based on these sequences, the isolate YJ17 and Bacillus amyloliquefaciens clustered within a group together and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate YJ17 was classified within the genus Bacillus as B. amyloliquefaciens YJ17. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens YJ17 were pH 7.0 and 50oC, respectively.

Introduction
 Materials and Methods
  Isolation of mannanase-producing bacteria fromspent mushroom substrates
  Morphological characteristics
  Fatty acid methyl ester analysis
  Utilization of carbon source
  DNA base composition
  Sequencing of 16S rRNA gene
  Sequence comparison and phylogenetic analysis
  Enzyme assays
 Results and Discussion
  Screening of mannan-degrading bacteria from fromspent mushroom substrates
  Morphological and physiological characteristics
  Chemotaxonomy
  16S rRNA sequence analysis
  Effect of temperature and pH on mannanase activity
 Acknowledgements
 References

• Hye Soo Kim(Dept. of Pharmaceutical Engineering, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea)
• Chul Hwan Kim(Dept. of Pharmaceutical Engineering, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea)
• Hyun Sook Kwon(Korea Promotion Institute for Traditional Medicine Industry, Gyeongsan, 712-260, Korea)
• Soo Jeong Cho(Dept. of Pharmaceutical Engineering, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea) Corresponding author