设为首页  |   加入收藏
引用本文:
【打印本页】   【下载PDF全文】   查看/发表评论  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 79次   下载 43 本文二维码信息
码上扫一扫!
分享到: 微信 更多
不同金属离子对稻田自然生物膜磷酸酶活性的影响
蔡述杰, 邓开英, 李九玉, 徐仁扣
土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所)
摘要:
以稻田自然生物膜为研究对象,研究不同浓度金属离子对生物膜酸性和碱性磷酸单酯酶(ACPase和ALPase)活性与酶反应动力学参数的影响。发现K+ 和Na+ 在0 ~ 1.0 mmol/L浓度下均对ACPase和ALPase无明显影响,Ca2+ 和Mg2+ 对ACPase和ALPase活性均有激活效应,可使磷酸酶活性最大提高14.1% 和46.7%;Zn2+、Cu2+、Mn2+、Al3+ 和 Ag+ 对ACPase和ALPase活性均有抑制作用。Co2+ 在低浓度时对ACPase和ALPase活性有一定的激活作用,高浓度时变为抑制作用;Cr6+ 在 0.1 mmol/L时对ACPase活性有促进作用,而在离子浓度0.25 ~ 1 mmol/L的范围内,均对ACPase活性产生抑制作用。通过酶反应动力学分析发现,Mg2+ 的加入使ACPase与底物的亲和力与催化效率增强,Cu2+ 对ACPase和ALPase的抑制作用主要是非竞争性抑制作用,Zn2+ 虽然提高ACPase与底物的亲和力,但是降低了ALPase与底物的亲和力与催化效率。金属离子对酶活性的影响因金属离子种类、浓度和磷酸酶类型而异,主要通过与酶活性位点或底物结合,改变酶的活性、对底物的亲和力,以及影响酶基因的表达等实现的。研究结果将为评估自然生物膜在稻田磷的生物地球化学循环中的作用,以及稻田受重金属污染的可能风险提供理论依据。
关键词:  自然生物膜  磷酸酶活性  金属离子  酶动力学常数  稻田
DOI:10.13758/j.cnki.tr.2020.03.015
分类号:S511
基金项目:国家重点基础研究发展计划(973计划)青年科学家专题(2015CB158220),国家自然科学基金项目(41877102)和中国科学院创新交叉团队和创新促进会项目(2014272)资助。
Effects of Metal Ions on Phosphatase Activity of Periphytic Biofilm in Paddy Fields
CAI Shujie, DENG Kaiying, LI Jiuyu, XU Renkou
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Abstract:
The effects of metal ions on acidic and alkaline phosphatase (ACPase and ALPase) activities and kinetic parameters of periphytic biofilm in paddy fields were studied. The results suggested that both K+ and Na+ had no significant effect on ACPase and ALPase activities in the concentration range of 0-1.0 mmol/L while both Ca2+ and Mg2+ had activating effects on ACPase and ALPase activities, which increased phosphatase activity by 14.1% and 46.7%, respectively. The metal ions of Zn2+, Cu2+, Mn2+, Al3+ and Ag+ all had inhibitory effect on ACPase and ALPase activities. While Co2+ could promote ACPase and ALPase activities at low concentration, but inhibit them at high concentration. And Cr6+ promoted ACPase activity at 0.1 mmol/L, while inhibited ACPase activity in the concentration range of 0.25-1.0 mmol/L. The addition of Mg2+ enhanced the affinity and catalytic efficiency of ACPase with substrates. The inhibitory effect of Cu2+ on ACPase and ALPase activities was mainly considered as non-competitive inhibition. Although Zn2+ increased the affinity of ACPase with substrate, it reduced the affinity and catalytic efficiency of ALPase with substrate. The effect of metal ions on enzyme activity varied with the type and concentration of metal ions, and the type of phosphatase. It is mainly achieved by binding with the site or substrate of enzyme activity, changing the affinity between enzyme activity and substrate, and influencing the expression of enzyme genes. The results can provide a theoretical basis for assessing the role of periphytic biofilm in the biogeochemical cycle of phosphorus in paddy fields, and the possible risk of heavy metal contamination in paddy fields.
Key words:  Periphytic biofilm  Phosphatase activity  Metal ions  Enzyme kinetic constant  Paddy fields

您是第3186870位访问者
版权所有 © 《土壤》编辑部
本系统由北京勤云科技发展有限公司设计   京ICP备09084417号