Intensive agriculture produces more than one million tons of organic waste mainly composed of lignocellulosic compounds. Though some management strategies have been lately adopted, many problems related to time and surface required for a proper treatment and final product quality remain unsolved. In this work, a staggered bioaugmentation process is proposed for the improvement of horticultural waste composting. Inocula were composed of 30 microbial strains previously isolated from identical composting piles, operated under the same conditions used in this work The high levels of biomass carbon at the beginning of the bio-oxidative phase and the parallel,evolution of reducing sugars reflected a quick adaptation of microbial inocula to the high temperatures reached during the process. Reducing sugar content during the process in the uninoculated pile was below 200 mu g g(-1), while a higher content was detected in the inoculated pile (2500 mu g g(-1)). Hemicellulose degraded at the end of the process in the inoculated pile was near to 85% whereas in the control pile was below 70%. Lignin degradation ratio was also higher in the inoculated pile (41% in comparison to 23% in the control pile). Moreover, several stabilization and humification indices supported that the bio-inoculation procedure here reported yields better quality products, earlier stabilized, from processes in which lignocellulosic carbon is more efficiently biotransformed. (C) 2014 Elsevier Ltd. All rights reserved.