Optimization of Organic Waste Composting Using the Effective Microorganisms Klebsiella oxytoca, Sphingomonas paucimobilis, and Pantoea spp.

Inadequate management of urban organic waste generates significant environmental impacts, including the accumulation of biodegradable residues and greenhouse gas emissions. Composting represents a key biotechnological strategy for the valorization of organic waste; however, its efficiency may be limited by long stabilization periods. This study evaluated the effect of a microbial consortium composed of Klebsiella oxytoca, Sphingomonas paucimobilis, and Pantoea spp. on the composting of organic waste generated at a higher education institution in Colombia using the Earthgreen SAC-2250 Autonomous Composting System. Four treatments based on different proportions of organic waste (OW) and sawdust (DM) were evaluated, and the best-performing formulation was subsequently inoculated with the microbial consortium and compared with a non-inoculated control pile. The 3:1 ratio (OW:DM) showed the best performance, reaching compost stabilization within 45 days. Inoculation with the microbial consortium reduced the stabilization time by approximately 20 days compared with the control treatment. These results demonstrate that microbial bioaugmentation using selected environmental isolates can significantly accelerate organic matter degradation and improve the efficiency of composting systems, providing a promising strategy for sustainable organic waste management in institutional environments.