Succession of the bacterial community and functional characteristics during continuous thermophilic composting of dairy manure amended with recycled ceramsite.

This study aimed to investigate variations of bacterial community and functional characteristics during the continuous thermophilic composting (CTC). Also their differences were discussed when amended with ceramsite and recycled ceramsite as the porous bulking agent. Results showed that the bacterial community shifted greatly and bacterial diversity increased as the CTC proceeded. Firmicutes and Chloroflexi was one of the major phyla at the active and late phase respectively. While Actinobacteria was the dominant phyla during the whole CTC. With the addition of ceramsite and recycled ceramsite, no significant difference was found of the overall bacterial variation trends. But the major phyla of Chloroflexi and Actinobacteria and major genes related to amino acid metabolism and carbohydrate metabolism increased significantly, especially when the recycled ceramsite was added. Redundancy analysis indicated that the succession of bacterial community was tightly related with the pH, water soluble organic carbon, NH4+-N, organic matter and germination index.