摘要
With increasing environmental application,biochar(BC)will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA(eDNA),which however still remains to be studied.Herein,the adsorption/desorption and the degradation by nucleases of eDNA on three aromatized BCs pyrolyzed at 700℃were firstly investigated.The results show that the eDNA was irreversibly adsorbed by aromatized BCs and the pseudo-second-order and Freundlich models accurately described the adsorption process.Increasing solution ionic strength or decreasing pH below 5.0 significantly increased the eDNA adsorption on BCs.However,increasing pH from 5.0 to 10.0 faintly decreased eDNA adsorption.Electrostatic interaction,Ca ion bridge interaction,andπ-πinteraction between eDNA and BC could dominate the eDNA adsorption,while ligand exchange and hydrophobic interactions were minor contributors.The presence of BCs provided a certain protection to eDNA against degradation by DNase I.BC-bound eDNA could be partly degraded by nuclease,while BC-bound nuclease completely lost its degradability.These findings are of fundamental significance for the potential application of biochar in eDNA dissemination management and evaluating the environmental fate of eDNA.
基金
supported by the National Natural Science Foundation of China(Nos.21976158,21525728,and 21677129)。
