镉对草海湿地沉积物中酸性磷酸酶活性的影响研究

Analysis of acid phosphatase activity in Guizhou Caohai sediments under the influence of exogenous cadmium

磷酸酶是水解性酶的一种,可以将含磷化合物去磷酸化,水解有机磷的磷酸酯或磷酸酐,在土壤的有机磷矿化过程中发挥重要作用。土壤pH值、土壤磷及重金属含量均会影响酸性磷酸酶活性的大小。目前关于重金属镉对酸性磷酸酶活性影响的研究罕见报道。该研究选取贵州草海湿地沉积物为研究对象,设置4个镉处理水平(0 mg/kg、10 mg/kg、20 mg/kg、40 mg/kg DW)以开展浓度梯度实验,培养不同时间(12 h,24 h,36 h,48 h)来开展时间梯度实验,采用对硝基苯磷酸盐法,研究沉积物中酸性土壤磷酸酶在不同浓度镉水平以及不同培养时间下的响应情况。结果表明,酸性土壤磷酸酶的活性与重金属镉处理浓度间存在显著相关性,随着镉处理浓度的增加,酸性磷酸酶活性逐渐降低;培养时间对镉处理沉积物的酸性磷酸酶活性也有显著影响,随着培养时间的延长,酸性磷酸酶活性逐渐降低。该研究丰富了目前对土壤酸性磷酸酶活性的认识,为进一步理解土壤环境及其对磷酸酶活性的影响提供了理论依据,也对土壤磷素的管理具有指导意义。

Phosphatase is one of the hydrolytic enzyme,which can dephosphorylate phosphorus compounds,hydrolyze organophosphorus phosphate and phosphoric acid anhydride.It plays an important role in the process of soil organic phosphate mineralization.Phosphorus,pH and heavy metal contents will affect the acid phosphatase activity.Current research on the impact of heavy metals on acid phosphatase activity are rare.In this study,Guizhou Caohai wetland sediments were selected as the research object,and four cadmium levels(0 mg/kg,10 mg/kg,20 mg/kg,40 mg/kg DW)were included in order to develop a concentration gradient experiment,different incubation time(12 h,24 h,36 h,48 h)were set up to carry out time gradient experiment,p-nitrophenyl phosphate method was adopted in order to study the response of the acidic soil phosphatase activity in sediments under different cadmium concentrations with levels under different incubation time.Results showed there was significant correlation between heavy metal cadmium pollution concentration and acidic soil phosphatase activity,and with the increasement of cadmium concentration,acid phosphatase activity gradually decreased;Cultivation time has significant influence on acid phosphatase activity,and with the extension of incubation time,the acid phosphatase activity was gradually reduced.The study enriches the understanding of soil acid phosphatase activity at present,and provides theoretical basis for further understanding the soil environment and the influence on phosphatase activity,which is of guiding significance to the management of soil phosphorus.