title: Influence of exogenous lead pollution on enzyme activities and organic matter degradation in the surface of river sediment.
abstract: As lead is one of the most hazardous heavy metals in river ecosystem, the influence of exogenous lead pollution on enzyme activities and organic matter degradation in the surface of river sediment with high moisture content were studied at laboratory scale. The dynamic changes of urease, catalase, protease activities, organic matter content, and exchangeable or ethylenediaminetetraacetic acid (EDTA)-extractable Pb concentration in sediment were monitored during different levels of exogenous lead infiltrating into sediment. At the early stage of incubation, the activities of catalase and protease were inhibited, whereas the urease activities were enhanced with different levels of exogenous lead. Organic matter content in polluted sediment with exogenous lead was lower than control and correlated with enzyme activities. In addition, the effects of lead on the three enzyme activities were strongly time-dependent and catalase activities showed lower significant difference (P < 0.05) than urease and protease. Correlations between catalase activities and EDTA-extractable Pb in the experiment were significantly negative. The present findings will improve the understandings about the ecotoxicological mechanisms in sediment.
authors: College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China, huangdanlian@hnu.edu.cn.
authors: Danlian
authors: D
authors: Huang
authors: Juanjuan
authors: J
authors: Xu
authors: Guangming
authors: G
authors: Zeng
authors: Cui
authors: C
authors: Lai
authors: Xingzhong
authors: X
authors: Yuan
authors: Xiangying
authors: X
authors: Luo
authors: Cong
authors: C
authors: Wang
authors: Piao
authors: P
authors: Xu
authors: Chao
authors: C
authors: Huang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D002374:Catalase / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D007854:Lead / Q000737:chemistry* / Q000302:isolation & purification; D010447:Peptide Hydrolases / Q000737:chemistry; D045483:Rivers; D014510:Urease / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D002614:Chelating Agents; D014874:Water Pollutants, Chemical; D007854:Lead; D004492:Edetic Acid; D002374:Catalase; D010447:Peptide Hydrolases; D014510:Urease