铜胁迫对农田土壤酶活性、细菌和古菌数量的影响

为了研究铜矿周边农田土壤中不同Cu含量对土壤酶活性、细菌和古菌基因拷贝数的影响,在铜矿周边农田土壤中采集了8个不同Cu含量的土壤,测定土壤的酶活性、细菌和古菌基因拷贝数,结果表明,土壤总Cu含量为28.30~1 019.27mg·kg~(-1),酸可提取态Cu含量为335~415.11 mg·kg~(-1),细菌16S rRNA基因拷贝数在每克干土3.10×10~(10)~1.84×10~(11)个之间,古茵16S rRNA基因拷贝数在每克干土737×10~8~6.82×10~9个之间。土壤总Cu和酸可提取态Cu含量对土壤脲酶活性影响较大,但对土壤脱氢酶和转化酶活性影响不显著。土壤细菌基因拷贝数均与总Cu含量、各形态Cu含量呈极显著的负相关关系,同样土壤古菌基因拷贝数与总Cu含量、各形态Cu含量也均呈极显著的负相关关系,说明Cu胁迫对土壤细菌和古菌活性具有较大的抑制作用。

Effects of Cu Stress on Enzyme Activity, Bacteria and Archaea Quantity in Soils

To study different Cu contents in surrounding soils of a copper smelting on soil enzyme activity, bacterial and archaeal quantity, eight soil samples were collected, and enzyme activity, bacterial and archaeal quantity in soils were determined. The results showed that the concentrations of total Cu and acid extractable Cu were in the ranges of 28.3-1 019.27 mg·kg^-1 and 3.35-415.11 mg·kg^-1, respectively. The ranges of gene copies numbers of bacteria and archaea were 3.10×10¹⁰-1.84×10¹¹ and 7.37×10⁸~6.82×10⁹ copies per gram of dry soil, respectively. The soil urease activity was significantly affected by total Cu and acid extractable Cu in soils, while soil dehyrogenase and incertase activity were not affected by them. There was significant negative relationship between gene copies of bacteria (or archaea) and total Cu (or different forms Cu), suggesting that the activities of bacteria and archaea could be inhibited by Cu stress.