The active role of metabolic regulators in nitrogen loss reduction and organic nitrogen transformation during different materials composting

Abstract

The tricarboxylic acid cycle experienced will cause a lot of carbon and nitrogen (N) losses during aerobic composting, and the greenhouse gases produced will do great harm to ecological balance and human health. Thus, the purpose of this study was to investigate the role of metabolic regulators like adenosine triphosphate and malonic acid in the organic N transformation and N loss reduction in the composting of chicken manure (CM) and garden waste (GW). Results showed that the addition of metabolic regulators promoted organic N transformation and significantly increased organic N content during composting. Concurrently, adding metabolic regulators reduced N loss, especially in GWATP and GWMA compost, the N loss reduced by 27.99% and 29.10%, respectively. However, metabolic regulators played different roles due to different basic properties of materials. The amino acid N, amino sugar N and hydrolysable unknown N (HUN) were stored in GW, while only amide N and HUN were stored in CM. Moreover, adding metabolic regulators significantly increased the core bacterial community associated with organic N transformation. Ultimately, structural equation model and variance partitioning analysis proved that adding metabolic regulators strengthened the effects of environmental factors and bacterial communities on the transformation and content of organic N. Therefore, adding metabolic regulators had positive effect on promoting N cycle.