CAJ | 학술논문

铬是环境中四大污染元素之一,其不同价态间对生物的生态毒性差异较大.采用模拟方法对Cr~(3+)和Cr~(6+)的土壤碱性磷酸酶效应进行了研究.结果表明,铬显著抑制了土壤碱性磷酸酶活性,其中Cr~(3+)的抑制作用远强于Cr~(6+),土壤轻度Cr~(3+)和Cr~(6+)污染时的临界浓度分别为151和1132 mg·kg~(-1),二者相差6.5倍;碱性磷酸酶活性及动力学特征参数V_(max)、k等与Cr浓度间达显著或极显著负相关,揭示土壤磷酸酶活性及V_(max)、k可作为土壤Cr污染的监测指标之一;模型U=β_0/(β_1×C+1)揭示酶与铬间的机理为完全抑制,动力学则进一步细化为非竞争性抑制;计算获得的抑制常数K_i为Cr~(3+)<Cr~(6+),反映出Cr~(3+)与土壤酶活性位点的亲合力远强于Cr~(6+).
락시배경중사대오염원소지일,기불동개태간대생물적생태독성차이교대.채용모의방법대Cr~(3+)화Cr~(6+)적토양감성린산매효응진행료연구.결과표명,락현저억제료토양감성린산매활성,기중Cr~(3+)적억제작용원강우Cr~(6+),토양경도Cr~(3+)화Cr~(6+)오염시적림계농도분별위151화1132 mg·kg~(-1),이자상차6.5배;감성린산매활성급동역학특정삼수V_(max)、k등여Cr농도간체현저혹겁현저부상관,게시토양린산매활성급V_(max)、k가작위토양Cr오염적감측지표지일;모형U=β_0/(β_1×C+1)게시매여락간적궤리위완전억제,동역학칙진일보세화위비경쟁성억제;계산획득적억제상수K_i위Cr~(3+)<Cr~(6+),반영출Cr~(3+)여토양매활성위점적친합력원강우Cr~(6+).
Chromium is was one of four heavy metals to pollute environment. However, its ecological toxicity to organism varies considerably for different species of chromium. In this paper, by simulative, soil alkaline phosphatase parameters are applied to study the effect of different valences chromium, Results showed that the Soil alkaline phosphatase activity was remarkably inhibited by chromium. Cr~(3+) was more seriously inhibited than Cr~(6+),the critical concentrations were 151 mg·kg~(-1) and 1 132 Mg·kg~(-1) for Cr~(3+) and Cr~(6+) respectively when soil is slightly polluted,6.5 times difference between Cr~(3+) and Cr~(6+). Alkaline phosphatase activity, V_(max) and k could he indexes to monitor soils polluted by chromium, because there were significant or remarkably significant correlation between soil alkaline phosphatase parameters and chromium concentrations. Their reaction mechanism was fully inhibited by model U=β_0/(β_1×C+1), and non-competitive inhibition by soil enzyme kinetic further. The inhibition constant K_i was Cr~(3+)<Cr~(6+), Cr~(3+) had stronger affinity than Cr~(6+) with active sites of alkaline phoshatase.