Exploring the characteristics of dissolved organic matter and succession of bacterial community during composting

The objective of this study was to explore the relationships among physico-chemical parameters, dissolved organic matters (DOM), and bacterial community during composting to better understand composting performances. The results showed total Kjeldahl nitrogen (TKN) (57%), temperature (39%), and pH (3%) were main factors driving the succession of bacterial communities. Firmicutes was a crucial phylum degrading organic matters for DOM formation, whereas the aromaticity and humification of DOM were closely related to Luteimonas (R2 = 0.971, p < 0.05) and Sphingobacteriaceae (R2 = 0.931, p < 0.05). Additionally, total phosphorus (TP), total potassium (TK), and TKN increased by 34.84%, 43.66%, and 65.91%, respectively, while organic matter decreased by 61.79%. The final compost had a C/N of 6.91 (<15) and a germination index of 97.81% (>80%), indicating that compost reached maturity and could be safely applied for soil amendment.