5854 Trends in Biosciences 8 (21), 2015 Isolation and Characterization of Compost Accelerating Microbes GAURI GOGOI 1 , PRANAMIKA SHARMA 2 , PREETI BURAGOHAIN 1 , AMRITA PHUKAN 1 AND RAJEN BARUAH 1 1 Department of Soil Science, AAU, Jorhat-13, Assam 2 Department of Plant Pathology, AAU, Jorhat-13, Assam Trends in Biosciences 8(21), Print : ISSN 0974-8431, 5854-5859, 2015 ABSTRACT A study was conducted to isolate compost accelerating microbes from rural composts. A total of five bacterial cultures and two fungal cultures were isolated in respective media and selected on the basis of qualitative & quantitative test. Qualitative screening was done on the basis of clear zone formation by growing the cultures in their respective media. The release of reducing sugars was estimated colorimetrically and was found to be highest in CDM B 1 (150 µg/ml/hr) followed by CDM B 2 (120 µg/ml/ hr) and CDM F 2 (205 µg/ml/hr) in case of bacteria and fungi respectively. In case of silicate solubilizing bacteria (SSB) the amount of silica release was recorded maximum in SSB 3 (55 µg/ml/hr). Key words CDM, SSB, Cellulose, Compost, Decomposition Composting is a bio-transformation process of organic wastes into partially mineralized organic matter mediated by certain groups of beneficial microorganisms. Hence, microorganisms are the essential factors for the successful operation of composting. The involvement of diverse microorganisms (both bacteria and fungi) growing under mesophilic or thermophilic conditions is prerequisite to compost formation. The composition of the microorganism communities depends, first and foremost, on the composition of components undergoing biodegradation and their relative contents in the mixtures. In order to effectively control the composting process, it is desirable to understand the beneficial microbial communities that are actively involved in biodegradation of hardy plant residues, viz., cellulose, hemicellulose and lignin which represent 40, 20-30 and 30 percent in plant residues respectivelyIn order to effectively control the composting process, it is desirable to understand the beneficial microbial communities that are actively involved in biodegradation of hardy plant residues, viz., cellulose, hemicellulose and lignin which represent 40, 20-30 and 30 percent in plant residues respectively. Cellulose being one of the important constituent in straw material, its degradation is primarily important in the process of composting. Wilson (2008) reported that aerobic microorganisms use the free cellulose mechanism to digest cellulose, although brown rot fungi appear to use different oxidative mechanism for degrading cellulose (Martioniz et al., 2009). Thermophilic microorganisms present during the thermophilic stage are largely represented by bacteria (Bacillus licheniformis, B. macerans and B. stearothermophilus) and, to a lesser extent, by fungi (Absidia corymbifera, Aspergillus fumigatus, Emericella nidulans, Penicillium diversum, Rhizomucor pusillis, Talaromyces thermophilus and Thermomyces lanuginosus), as well as by yeasts and basidiomycetes. The microbial process of biodegradation varies with the nature of substrates used for composting. For instance, rice straw when extensively used as substrate, needs another group of microorganisms having ability to solubilize silica bound with epidermal layers that exceed lignin content. Paddy straw is widely available substrate for compost making. However, due to wide C: N ratio (80: 1), high silica content, high tensile strength, high lignin & cellulose content and slow decomposition rate, straw is infrequently used as organic substrate (Kumar et al., 2006). Therefore, the most desirable approach is to accelerate the decomposition of straw using some effective microbes. MATERIALS AND METHODS The samples in bulk were collected randomly from different rural compost pits made with different substrates viz., plant residues, azolla, rice straw, weed residues, and partially decomposed compost pit. The individual sample was air dried to 10% moisture level. The Dubo’s cellulose enrichment technique was used to isolate the cellulose degrading microbes from the collected samples. Individual sample was serial diluted upto 10 -7 and each dubos media was inoculated with diluted test sample in triplicate. A long strip of sterile filter paper was inserted into each flask so that one