生物炭中持久性自由基对秀丽隐杆线虫的毒性

Neurotoxic effect of environmental persistent free radicals in rice biochar to Caenorhabditis elegans

为了评价生物炭的使用对生态系统,尤其是对土壤无脊椎动物的毒性影响,使用模式生物秀丽隐杆线虫(Caenorhabditis elegans, C. elegans)来评估生物炭的环境风险.观察了生物炭原样、生物炭颗粒物和生物炭浸提液对线虫神经行为学评价指标(身体摆动频率、相对运动长度、排泄间隔时间、碰触反应率和化学感知行为指数)的影响;并结合生物炭的理化性质、非金属元素组成和重金属元素含量以及环境持久性自由基(EPFRs)的强度,评估生物炭对线虫的生物毒性.结果显示,EPFRs信号强的生物炭和颗粒物对秀丽隐杆线虫有一定的毒物兴奋效应,EPFRs信号微弱的浸提液无显著性影响.因此,生物炭中的EPFRs对秀丽隐杆线虫有潜在的神经毒性作用.

As an effective soil amendment, biochars have attracted increasing research attention, while their environmental risks have not been fully explored. Studies on the effects of biochars on ecosystem, especially on soil invertebrates, are still scarce. The model organism, Caenorhabditis elegans(C. elegans, nematode), was used to assess the potential neurotoxicity of biochar. The neurobehaviors of C. elegans, including their body bends, relative move length, defecation, touch response and chemical index, were investigated after 24 h-exposed in biochars, the washed biochars and biochar supernatants. The contents of metallic and non-metallic elements, biochar physicochemical properties and the environmentally persistent free radicals(EPFRs) were characterized. The results showed a hormesis behavior of C. elegans when exposed in biochar particles with high EPFRs intensity. No significant effect to C. elegans was observed when exposed in supernatants. Compared to the other endogenous pollutants in biochars, EPFRs have a potential neurotoxic effects to nematodes. This study provides a new angle to assess the potential environmental risks of biochar application.