Insights into the functionality of fungal community during the large scale aerobic co-composting process of swine manure and rice straw

Abstract

Composting is a cost-efficient method of transferring various unstable and complex organic matters into a stable and humus-like substance, during which various fungus play a critical role in the decomposition of organic matters. In this study, the rice straw and swine manure co-composting were carried out in a pilot-scale, and the evolution of various biochemical parameters and fungi community were detected at different time points. The results showed that most of the parameters fluctuated strongly at the thermophilic phase (THP), and the Canonical Correlation Analysis (CCA) results showed that Mycothermus spp. and Aspergillus spp. were with abundances of 47.82% and 3.51%, respectively, which were considered as the core fungi during the composting process. In addition, five culturable thermophilic filamentous fungi were isolated from the samples obtained at the high temperature stage, among which Aspergillus fumigatus were considered as the core specie at this special phase. The capacity of lignocellulose degradation of this strains was also evaluated by analyzing the secretomes in a coculture group with rice straw and crystalline cellulose as carbon sources, and the identified proteins illustrated that the enzymes were chiefly secreted by A. fumigatus in both treatments, with the abundances of 91.41% and 85.19%, respectively.