Dynamic changes of the dominant functioning microbial community in the compost of a 90-m3 aerobic solid state fermentor revealed by integrated meta-omics

The dynamic changes in the composition and function of both bacterial and fungal communities over time and at various depths in the compost of a 90-m3 industrial-scale fermentor were explored using integrated meta-omics. The microbial communities in the middle layer (1.2 m) of the compost developed a stable and simple structure over time, which was mainly composed of Thermobifida, Bacillus, Thermomyces and Aspergillus. According to the metaproteomic results, the bacterial community was more focused on cellulose degradation, characterized by 44% of the cellulases that were secreted by Thermobifida, while the fungal community was more likely to degrade hemicellulose, mainly via Thermomyces and Aspergillus. The results revealed that, under artificial control of the temperature and oxygen concentration, the efficiency of organic waste degradation was greatly increased and the fermentation cycle was shortened to 11 days.