纳米银对小麦秸秆还田土壤中酶活性及微生物群落功能多样性的影响

Effect of silver nanoparticles on soil enzyme activity and functional diversity of microbial communities in wheat-straw-returned soil

采用室内培养的方式,设置空白对照组(无添加,CK)、土壤+小麦秸秆组(SW)、土壤+小麦秸秆+纳米银组(AgSW),探究纳米银对秸秆还田农田土壤的呼吸作用,碳循环相关酶包括过氧化物酶、多酚氧化酶和纤维素酶的活性,微生物群落功能多样性的影响。结果显示:与CK组相比,添加小麦秸秆的SW组提升了土壤呼吸速率,使CO2累计释放量增加了9.9%;与SW组相比,添加纳米银的AgSW组抑制了土壤呼吸作用,CO2累计释放量减少36.8%,同时3种酶活性显著降低,过氧化物酶、多酚氧化酶和纤维素酶的活性可分别最高降低25.1%、27.1%和14.3%;微生物群落水平生理特征(CLPP)分析结果发现,纳米银显著降低了微孔板平均孔颜色变化率(与SW组相比下降了73.8%)和微生物多样性与丰富度。研究认为纳米银通过抑制土壤酶与微生物活性改变了土壤有机质分解的生态学过程,使微生物群落功能多样性降低。

An indoor cultivation system was used to study the environmental impact of nano silver on various soil characteristics,such as soil respiration,carbon-conversion-related enzyme activities,and functional diversity of microbial community.The experimental sample was set as blank control boil(untreated,CK),wheat-straw-returned soil(SW),nano silver amended soil(AgSW).The results showed that when compared with blank control soil,wheat-straw-returned soil had increased the soil respiration rate,cumulative release of CO2 was increased by 9.9%.Further,nano-silver amendment inhibited soil respiration in comparison with wheat straw treatment,and cumulative release of CO2 was reduced by 36.8%,the activities of peroxidase,polyphenol oxidase,and cellulase were considerably reduced highest by 25.1%,27.1%,and 14.3%,respectively.The results of microbial community level physiological characteristics revealed that nano silver significantly reduced the average well color development(AWCD)(reduced by 73.8%compared with SW)as well as microbial diversity and richness.The results show that nano silver alters the ecological process of soil organic matter decomposition by inhibiting soil microbial activity and reduces the functional diversity of microbial communities.