The changes in functional marker genes associated with nitrogen biological transformation during organic-inorganic co-composting

In this article, the changes in the functional marker genes associated with nitrogen biological transformation during the organic-inorganic co-composting process with adding biochar or not were studied. Results showed that the addition of biochar increased the abundance of ureC, AOA amoA and AOB amoA gene while decreased the abundance of nirK gene. The addition of 10% biochar by weight ratio was better for the optimization of nitrogen biological transformation process. The correlation analysis showed that the ureC gene was highly correlated with NH₄⁺-N concentration while the AOA amoA and AOB amoA genes were moderately correlated with NH₄⁺-N concentration. Similarly, the nirK gene was moderately correlated with NO₃^--N concentration. This work would contribute to understanding the mechanisms underlying in the nitrogen bio-transformation further at the molecular level during organic-inorganic co-composting.