Work

Biochar and manganese dioxide regulate nitrogen transformation via quorum sensing of core microbiota in compost

Year: 2025

Type: article

Abstract: Improving the efficiency of element cycling and elucidating its microbiological mechanisms in aerobic composting is crucial for utilizing industrial and agricultural waste as a resource. This study aimed to analyze and compare the effects of two conditioners, biochar and manganese dioxide (MnO 2 ), on inorganic nitrogen transformation in the aerobic composting process of a mixture of flax retting liquor (FRW), straw, and chicken manure from the perspective of quorum sensing signaling molecules and two-component system (QSM-TCS). The results indicated that during the aerobic composting of a mixture of corn straw and chicken manure, the addition of FRW resulted in a 39.2 % increase in total nitrogen content. Additionally, adding conditioners, such as biochar and MnO 2 , continuously enhanced nitrogen transformation. Furthermore, biochar reduced NH 4 + -N loss by 32.26 %, and MnO 2 decreased NO 3 − -N loss by 2.10 %. Biochar improved temperature perception in core operational taxonomic units, promoting genera such as Ornithinicoccus and Thermobifida , and thereby enabling them to better use the luxQ - luxN , rpfC - rpfG , and qseC - qseF gene pathways to accelerate NH 4 + -N accumulation. In contrast, MnO 2 enhanced microbial adaptation to pH changes, increasing pH tolerance in bacteria such as Enterococcus and Bacillus , which stimulated genes involved in nitrification and anaerobic ammonium oxidation. This facilitated complementary effects in the QSM-TCS system, thereby stabilizing NO 3 − -N retention. The findings highlighted the critical role of microbial-driven inorganic nitrogen transformation pathways, offering insights into the optimization of aerobic composting systems for sustainable agriculture and environmental protection.

Source: Earth Critical Zone

DOI: 10.1016/j.ecz.2025.100037