Comparative paddy straw degradation potential of Psychrotrophic Fungal Consortia and Pusa Decomposer at low temperatures

Low temperatures impose a major limitation on microbial activity, restricting nutrient utilization and slowing the decomposition of crop residues in cold regions. This study investigated the degradation potential of psychrotrophic fungal consortia in comparison with Pusa Decomposer (PD) at 10, 15, and 20 °C. Among the tested consortia, MC 1 comprising Penicillium aethiopicum LTF 1, Penicillium echinulatum LTF 13, and Penicillium chrysogenum LTF 21 proved the maximum degradation efficiency. MC 1 attained a Relative Degradation Rate (RDR) of 43.63 ± 4.61 % and a C:N ratio of 46.33 ± 1.52 on finely chopped straw (2–3 cm) after 42 days which outperforms PD and other consortia. Significant reductions in straw Cutting Strength, Total Cellulose (TC), Total Lignin (TL), and Total Hemicellulose (THC) contents were recorded, alongside the highest mineralizable carbon and decay rates as indicated by cumulative CO₂ evolution assays. Temperature quotient (Q₅) values confirmed optimum degradation efficiency at 15–20 °C. Scanning electron microscopy revealed clear structural modifications in MC 1 treated straw, consistent with advanced degradation. Collectively, the results highlight MC 1 as a promising psychrotrophic consortium for efficient paddy straw decomposition under low temperature conditions, with potential applications in sustainable residue management and nutrient recycling in cold agroecosystems.