Succession of the bacterial community structure and functional prediction in two composting systems viewed through metatranscriptomics.

• Bacterial community succession was detected in two different composting process. • Investigating bacterial communities was based on metatranscriptomics. • Succession of metabolism function of bacterial community was analyzed by PICRUSt. • Bacterial community succession was tightly related to AP in a bioreactor system. In this work, Illumina MiSeq sequencing of cDNA from metatranscriptomics RNA reverse transcription were employed in combination with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) to estimate the dynamic variations of bacterial community structures and metabolic functions in a bioreactor and traditional composting process. Results showed that the change of bacterial α-diversity in the first three stages exhibit opposite trends in the two composting systems. The four most abundant phyla were the same in both systems (Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria), but the most abundant genera were different. The five most abundant genus-level groups in the bioreactor were Psychrobacter, Galbibacter, Pseudomonas, Staphylococcus and Flavobacterium. Within the same phase, the functional bacteria were dramatically different in the two composting processes. In the bioreactor system both bacterial community structure and metabolism function were greatly affected by available phosphorus. [ABSTRACT FROM AUTHOR]