Introduction Agricultural residue burning represents a critical nexus between food security and climate crisis, with rice straw combustion alone contributing 141.15 Mt CO 2 equivalent emissions annually in India. This study addresses this issue by developing a microbial consortium approach to convert agricultural waste into a carbon-sequestering soil amendment, simultaneously mitigating climate impact and soil degradation. Methods Microbial cultures were isolated from cow dung, partially degraded straw, and forest soil, and screened for lignocellulolytic enzyme activity. Three efficient isolates were identified via 16S rRNA and ITS gene sequencing as Bacillus subtilis (IIRRSDB-6), Pseudomonas aeruginosa (IIRRSDB-7), and Mariannaea camptospora (IIRRSDF-3). These isolates were selected to develop a microbial consortium and evaluated under in vitro conditions for lignocellulose degradation efficiency. Results The microbial consortium exhibited strong enzymatic synergy, with B. subtilis showing peak lignin peroxidase activity (3.177 U/mL) and laccase production (4.245 U/mL), while M. camptospora recorded maximum laccase activity (5.547 U/mL). Rice straw decomposition was significantly enhanced, reducing the carbon-to-nitrogen ratio from 66.24 to 19.45 within 60 days (70.6% improvement). Nutrient enrichment was observed, with nitrogen increasing from 0.7 to 1.62% (131%), phosphorus from 0.17 to 0.28% (64.7%), and potassium from 1.53 to 2.09% (36.6%). Structural biomass degradation included reductions in acid detergent fiber (40.3%), cellulose (41.3%), and lignin (55.7%). Conclusion The developed microbial consortium effectively transforms agricultural residues into nutrient-rich, carbon-sequestering soil amendments. This provides a scalable and sustainable alternative to residue burning, promoting waste valorization, soil fertility improvement, and climate change mitigation.
Anveshitha et al. (Fri,) studied this question.