International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 2 Number 6 (2013) pp. 162-175
Functional and genetic characterization of culturable bacteria associated with late phase of mushroom composting assessed by amplified rDNA restriction analysis
Abhinay Sharma1 , Ajay Veer Singh2* and Bhavdish N. Johri3
1Department of medical microbiology, Helmholtz center for infection research, Inhofenstrasse, 7, Braunschweig, Germany 2Department of Microbiology, College of Basic Sciences & Humanities, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar 263145, India. 3Department of Biotechnology, Barkatullah University, Bhopal 462 026, India *Corresponding author e-mail: ajaygbpuat@gmail.com
A B S T R A C T
The edible mushroom Agaricus bisporus is grown commercially on composted manure/straw mixtures. Mushroom composting is a fermentation process in which various groups of microorganisms play important role at different stages of composting. Present study was conducted to explore the mesophilic culturable bacterial diversity in late phases of mushroom composting. Morphologically all the isolated bacteria were gram positive rods. The functional diversity of the bacterial isolates was examined by plate enzyme assays, siderophore production, antagonistic property and quantitative enzyme assays. Good enzymatic activity for amylase, cellulase, xylanase and protease was reported for different bacterial isolates. Fifteen bacterial isolates showed siderophore production activity. During antibiosis assay most of the isolates inhibited growth of Verticillium fungicola but not of Mycogone perniciosa. However, Consortium of selected bacterial isolates produced good amounts of lytic enzymes (amylase, cellulase, xylanase and protease) in solid state fermentation experiment that might help in enhancing composting process. Amplified 16S-rDNA restriction analysis (ARDRA) showed that only two bacterial isolates (JCA and KCA) were 100% similar in all three restriction profiles (Sau 3AI, Msp I and Taq I) and two isolates (FC and HC) were 100% similar in two restriction profiles (Sau 3AI and Taq I). However, other isolates exhibited discriminatory relationship with each other when analyzed for combinations of restriction profiling. The present study reveals bacterial diversity and community succession in late phase of composting process as well as emphasizes on application of bacterial consortium to enhance composting process.
Keywords
Mushroom composting; Agaricus bisporus; ARDRA; 16S rDNA; Phylogenetic diversity