纳米富勒烯对土壤酶活性和微生物群落的影响

Effects of nano-fullerene on soil enzyme activities and microbial community

采用室内暗培养试验,研究了纳米富勒烯对土壤呼吸强度、酶活性及微生物结构群落多样性的影响.结果表明,添加纳米富勒烯抑制了土壤呼吸强度(p<0.05),较对照处理CO2累积量降低了1.2%~11.3%.纳米富勒烯显著抑制了土壤脲酶活性(p<0.05),与对照相比,降低了19.1%~33.7%,土壤脱氢酶活性整体上表现为随纳米富勒烯添加量增加先增加后降低的趋势.与之相反,添加不同剂量纳米富勒烯整体上提高了土壤碱性磷酸酶活性,但差异不明显(p>0.05).利用磷脂脂肪酸(Phospholipid Fatty Acids,PLFAs)分析发现,添加纳米富勒烯(10~500 mg·kg^-1)后土壤总PLFAs含量较对照降低了3.6%~27.3%,在低剂量(≤50 mg·kg^-1)纳米富勒烯处理下革兰氏阳性细菌、革兰氏阴性细菌、真菌、细菌含量均有所提升,而当纳米富勒烯剂量达到500 mg·kg^-1时,土壤微生物数量在不同程度上受到抑制.土壤微生物生态学指数(Shannon、Simpson和Pielou指数)、聚类分析(Cluster analysis)、主成分分析(Principal component analysis)均显示纳米富勒烯对土壤中微生物群落多样性产生了负面影响.

The effects of nano-fullerene(NF)on soil respiration,enzyme activity and microbial community diversity were studied by in-house dark culture experiments.The results show that the addition of NF inhibited the soil respiration intensity(p<0.05),with a decrease of 1.2%~11.3%,and the Soil urease activity was significantly inhibited(p<0.05),with 19.1%~33.7%reduction,when compared with control.With the increase of NF content,the activities of soil dehydrogenase initially increased slightly and then decreased,while the alkaline phosphatase activity increased,and both of them were not obviously significant(p>0.05).In contrast to the control,the mount of total phospholipid fatty acids(PLFAs)and actinomycetes in the soil decreased by 3.6%~27.3%with the addition of NF.Under lower NF content(≤50 mg·kg^-1),the population of gram-positive bacteria,gram-negative bacteria,fungi and bacteria enhanced;but when NF was up to 500 mg·kg^-1,all the above mentioned microbial communities were inhibited.Soil microbial ecological indices(Shannon,Simpson and Pielou index),cluster analysis,and principal component analysis results indicate that NF had a negative impact on soil microbial community diversity.