Effectiveness of inoculation with isolated Geobacillus strains in the thermophilic stage of vegetable waste composting

• Published in: Bioresource technology 2010-04, Vol.101 (8), p.2892-2895
• Main Authors: Sarkar, Sutripta, Banerjee, Rajdeep, Chanda, Sunanda, Das, Pradeep, Ganguly, Sandipan, Pal, Subrata
• Format: Article
• Language: English
• Subjects: 16S rRNA gene; Agronomy. Soil science and plant productions; Animals; Base Sequence; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biotechnology; Carbon - metabolism; Cattle; cattle manure; cellulolytic microorganisms; composting; Dehydrogenase activity; Environment and pollution; enzyme activity; Flow Cytometry; food wastes; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Geobacillus; Geobacillus - genetics; Geobacillus spp; Industrial applications and implications. Economical aspects; Inoculum development; Manure - microbiology; Molecular Sequence Data; MSW composts; Nitrogen - metabolism; organic wastes; Oryza; Oryza sativa; oxidoreductases; Refuse Disposal - methods; rice straw; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Soil; Soil Microbiology; solid wastes; thermophilic bacteria; Use of agricultural and forest wastes. Biomass use, bioconversion; Vegetables; Waste management
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2009.11.095

An inoculum containing two amylolytic and three cellulolytic thermophilic bacteria, isolated from a preceding compost pile and identified as Geobacillus species by 16S rRNA gene sequencing, was applied to a mixture of market waste, rice straw and cow dung (5:1:0.2) so that the initial cell density was 2 × 10 8 colony forming unit (CFU) per gram dry weight at 55 °C. The inoculation increased the total cell count particularly in the thermophilic stage as determined by flow cytometry. Concomitantly, there was a significant rise in microbial metabolism in the compost pile as reflected by the dehydrogenase activity. As a result, the C/N ratio dropped more rapidly in the inoculated mixture than that in the control without inoculum. The study, therefore, suggested that inoculation by thermophilic bacteria would be effective in the composting process at least in the thermophilic stage.