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漆酶广泛存在于自然界中,它是一种含铜氧化酶。于1883年Yoshida首次发现[1],1894年Bertrand将其命名为“漆酶”,在自然界中,按漆酶分为漆树漆酶(rhus laccase)和真菌漆酶(fungal laccase)两大类[2]。漆酶是二聚或者四聚糖蛋白,为了发挥其催化作用,漆酶依赖于分布在不同活性中心的4个铜离子[3]。漆酶的催化效率高、催化条件温和,漆酶的活性主要受环境的温度、pH值和其自身的等电点等影响,真菌漆酶的最适温度一般在25—50 ℃,最适pH值范围为4.0—6.0之间 [4-6]。漆酶催化机理是利用氧分子作为电子受体,催化氧分子还原为水用于降解不同的环境污染物[7],没有二次污染,已被广泛用于自然水体中多环芳烃、农药以及氯酚类污染物的降解[8]。
对乙酰氨基酚(acetaminophen,AAP),又称扑热息痛,最常用的非处方药之一,是一种快速有效的止痛和退烧药物[9-10]。人类及哺乳动物服用AAP后,药物大多以原形或初级代谢产物排泄到体外,最终通过多种途径进入环境。据报道,在地表水甚至地下水中,AAP普遍以μg·L−1的浓度存在水体中。数据显示,美国 139 条河流中,AAP 的最大浓度为 10 μg·L−1,英国泰恩河中 AAP 的浓度则达到了 65 μg·L−1[11-12]。在饮用水和废水的氯化消毒过程中大量的乙酰氨基酚很容易转化为1,4-苯醌和乙酰基对苯醌,两者都具有相当的毒性,AAP及其转换产物均容易导致肝脏和肾脏的损害[13]。当其在污水处理厂处理过程中会沉积在污泥里,污泥会作为肥料用到农田,进入土壤系统[14]。因此,对AAP去除技术的研究与开发已成为近期研究的热点。目前已经有研究发现在水生环境中胞外酶可以对AAP进行降解[15],但是对于土壤体系下AAP的降解转化研究却较少。关于真菌漆酶降解土壤中的多环芳烃已经有大量的研究[16],而对于实际土壤介质对漆酶降解AAP的影响却研究较少,所以有必要进行这方面的研究。
本文探究了不同地区土壤介质对漆酶降解AAP的影响,比较了不同土壤介质对AAP吸附性能的差异以及对漆酶酶活的影响,揭示了不同土壤介质对漆酶降解AAP效果差异的原因,为后续土壤介质体系胞外酶降解酚类污染物提供研究参考。
在不同土壤体系下漆酶催化降解对乙酰氨基酚的差异研究
Effects of laccase degradation on acetaminophen in different soil systems
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摘要: 漆酶广泛分布在天然环境中,可以有效催化降解水体和土壤中有机污染物。对乙酰氨基酚(Acetaminophen,AAP)是一种最常用的止痛和退烧药物,环境残留浓度较高,AAP及其转换产物均易导致肝脏和肾脏的损害。研究表明,在水体介质中漆酶可以有效降解AAP,但是对于土壤介质中漆酶降解AAP的研究却较少。本文系统地研究了不同地区土壤(江苏宜兴水稻土、陕西洛川黑垆土、江西鹰潭红土和广东德庆砖红土)体系下漆酶降解AAP的差异,包括其对AAP的吸附作用和对漆酶的酶活影响。结果表明,组成成分淤泥含量较高的江苏宜兴水稻土和陕西洛川黑垆土对AAP的吸附性能较大,平衡吸附量分别为12.03 mg·g−1和28.37 mg·g−1,而江西鹰潭红土和广东德庆砖红土对AAP无明显吸附。江西鹰潭红壤土介质中,酶的活性是最稳定的,同时在该土壤介质中漆酶对AAP的降解效果优异,而陕西洛川由于土壤介质pH值呈弱碱性,在该pH条件下漆酶的活性较低,因此对于污染物AAP的降解效率也较低。江苏宜兴水稻土介质中的酶活相对广东德庆砖红土较高,但是土壤介质中SOM的含量较多,综合在降解效果与广东德庆砖红土接近。本研究为评价实际土壤介质对漆酶降解环境污染物提供科学依据。Abstract: Laccase is widely distributed in the environment and can effectively degrade persistent pollutants in water. Acetaminophen (AAP) is one of the most commonly prescribed over-the-counter drugs to relieve pain and reduce fever, with high environmental residual concentrations. Both AAP and its conversion products are likely to affect human health. Previous studies have shown that laccase can effectively degrade AAP in aqueous media, but there are few studies on laccase degradation of AAP in soil media. This study systematically investigated the effects of soils from different site on the laccase-catalyzed removal of AAP, including the adsorption and enzyme activity. Four different soils were sampled from Yixing paddy soil in Jiangsu, Luochuan black soil in Shaanxi, Yingtan red soil in Jiangxi, and Deqing brick red soil in Guangdong. The results showed that Jiangsu Yixing paddy soil and Luochuan black soil in Shaanxi had higher adsorption capacity for AAP, with saturated adsorption capacities of 12.03 mg·g−1 and 28.37 mg·g−1, respectively. Yingtan red soil in Jiangxi and brick red soil in Deqing, Guangdong did not significantly adsorb AAP. The enzyme activity is the most stable in Yingtan red soil. At the same time, the degradation effect of laccase on AAP is excellent in this soil. In Luochuan black soil, the activity of laccase was low because the pH value was weakly alkaline, so the degradation efficiency of pollutant AAP was also low. However, the enzyme activity in the Yixing paddy soil in Jiangsu is relatively high, but the content of SOM in soil was high, so the degradation effect was similar to that in Deqing brick red soil. This study provides a scientific basis for evaluating soil for laccase degradation of environmental pollutants.
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Key words:
- laccase /
- soil /
- acetaminophen /
- degradation /
- adsorption
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表 1 实验土壤及理化性质
Table 1. Experimental soil and physical and chemical properties
土样来源
Soil source土壤种类
Soil typepH SOM/(g·kg−1) 比表面积/(m2·g−1)
Specific surface area结构/%
Component黏粒
Clay淤泥
Silt沙粒
Sand江西鹰潭 红壤 4.50 12.40 36.17 6.65 30.98 62.37 江苏宜兴 水稻土 5.68 20.20 6.04 5.75 90.96 3.29 陕西洛川 黑垆土 7.71 12.90 16.28 7.25 76.61 16.14 广东德庆 砖红壤 4.85 4.14 20.97 12.69 66.81 20.50 表 2 AAP在受试土壤上的吸附动力学参数
Table 2. Adsorption kinetic parameters of AAP on the tested soil
土样来源
Soil source反应温度/℃
Reaction temperature准一级动力学
Pseudo-first-order准二级动力学
Pseudo-second-orderqe/(mg·g−1) k1/h−1 r2 qe/(mg·g−1) k2/(g·(mg·h)−1) r2 陕西洛川 25 28.37 0.038 0.981 39.97 0.0007 0.972 江苏宜兴 25 12.03 0.054 0.894 15.13 0.0036 0.893 -
[1] THURSTON, C F. The structure and function of fungal laccases [J]. Microbiology-Sgm, 1994, 140: 19-26. doi: 10.1099/13500872-140-1-19 [2] MAYER A M, STAPLES R C. Laccase: new functions for an old enzyme [J]. Phytochemistry, 2002, 60(6): 551-565. doi: 10.1016/S0031-9422(02)00171-1 [3] MATERA I, GULLOTTO A, TILLI S, et al. Crystal structure of the blue multicopper oxidase from the white-rot fungus trametes trogii complexed with p-toluate [J]. Inorganica Chimica Acta, 2008, 361: 4129-4137. doi: 10.1016/j.ica.2008.03.091 [4] MOUGIN C, JOLIVALT C, BRIOZZO P, et al. Fungal laccases: From structure-activity studies to environmental applications [J]. Environmental Chemistry Letters, 2003, 1(2): 145-148. doi: 10.1007/s10311-003-0024-9 [5] YANG J, YANG X, LIN Y, et al. Laccase-catalyzed decolorization of malachite green: Performance optimization and degradation mechanism [J]. Plos One, 2015: 10. [6] DWIVEDI U N, SINGH P, PANDEY V P, et al. Structure-function relationship among bacterial, fungal and plant laccases [J]. Journal of Molecular Catalysis B-Enzymatic, 2011, 68: 117-128. doi: 10.1016/j.molcatb.2010.11.002 [7] POLYAKOV K M, GAVRYUSHOV S, IVANOVA S, et al. Structural study of the X-ray-induced enzymatic reduction of molecular oxygen to water by Steccherinum murashkinskyi laccase: Insights into the reaction mechanism [J]. Acta Crystallographica. Section D, Structural Biology, 2017, 73(5): 388-401. doi: 10.1107/S2059798317003667 [8] ZHAO Y C, YI X, LI M H, et al. Biodegradation kinetics of DDT in soil under different environmental conditions by laccase extract from White Rot Fungi [J]. Chinese Journal of Chemical Engineering, 2010, 18(3): 486-492. doi: 10.1016/S1004-9541(10)60247-9 [9] DE GUSSEME B, VANHAECKE L, VERSTRAETE W, et al. Degradation of acetaminophen by delftia tsuruhatensis and pseudomonas aeruginosa in a membrane bioreactor [J]. Water Research, 2011, 45: 1829-1837. doi: 10.1016/j.watres.2010.11.040 [10] SEBASTINE I M, WAKEMAN R J. Consumption and environmental hazards of pharmaceutical substances in the UK [J]. Process Safety and Environmental Protection:Transactions of the Institution of Chemical Engineers, Part B, 2003, 81(4): 229-235. doi: 10.1205/095758203322299743 [11] ROBERTS P H, THOMAS K V. The occurrence of selected pharmaceuticals in wastewater effluent and surface waters of the lower Tyne catchment [J]. The Science of the Total Environment, 2006, 356(1/2/3): 143-153. [12] SIM W J, LEE J W, OH J E. Occurrence and fate of pharmaceuticals in wastewater treatment plants and rivers in Korea [J]. Environmental Pollution, 2010, 158(5): 1938-1947. doi: 10.1016/j.envpol.2009.10.036 [13] BEDNER M, MACCREHAN W A. Transformation of acetaminophen by chlorination produces the toxicants 1, 4-benzoquinone and N-acetyl-p-benzoquinone imine [J]. Environmental Science & Technology, 2006, 40(2): 516-522. [14] LI J Y, YE Q F, GAN J. Degradation and transformation products of acetaminophen in soil [J]. Water Research, 2014, 49: 44-52. doi: 10.1016/j.watres.2013.11.008 [15] VEITCH N C. Horseradish peroxidase: A modern view of a classic enzyme [J]. Phytochemistry, 2004, 65(3): 249-259. doi: 10.1016/j.phytochem.2003.10.022 [16] WU Y C, TENG Y, LI Z G, et al. Potential role of polycyclic aromatic hydrocarbons (PAHs) oxidation by fungal laccase in the remediation of an aged contaminated soil [J]. Soil Biology and Biochemistry, 2008, 40: 789-796. doi: 10.1016/j.soilbio.2007.10.013 [17] Auriol M, Filali-Meknassi Y, Tyagi R D, et al. Laccase-catalyzed conversion of natural and synthetic hormones from a municipal wastewater [J]. Water Research, 2007, 41(15): 3281-3288. doi: 10.1016/j.watres.2007.05.008 [18] 石欢欢. 漆酶催化降解杀菌剂苄氯酚和双氯酚的机理研究[D]. 南京: 南京大学, 2016. SHI H H. Study on the mechanism of laccase-catalyzed removal of the antimicrobials chlorophene and dichlorophen [D]. Nanjing: Nanjing University, 2016(in Chinese).
[19] BOLEL P, HALDER M. Fluorescence quenching of carmoisine by viologens in neat methanol: Observation of inversion in quenching [J]. Chemical Physics Letters, 2011, 507: 234-239. doi: 10.1016/j.cplett.2011.03.054 [20] GONG Z, WANG G, SHI H, et al. Mn(Ⅱ)-Mn(Ⅲ)-Mn(Ⅳ) redox cycling inhibits the removal of methylparaben and acetaminophen mediated by horseradish peroxidase: New insights into the mechanism [J]. Science of the Total Environment, 2021, 788: 147788. doi: 10.1016/j.scitotenv.2021.147788 [21] 李建华. 模拟自然光照下胞外过氧化物酶去除水中典型内分泌干扰物机理研究[D]. 南京: 南京大学, 2017. LI J H. Removal mechansim of representative endocrine disruptors from water mediated by extracellular peroxidase under simulated solar light [D]. Nanjing: Nanjing University, 2017(in Chinese).
[22] HU J Q, YANG S Z, GUO L, et al. Microscopic investigation on the adsorption of lubrication oil on microplastics [J]. Journal of Molecular Liquids, 2017, 227: 351-355. doi: 10.1016/j.molliq.2016.12.043 [23] 刘鹏, 王焓钰, 吴小伟, 等. 粒径对聚苯乙烯微塑料吸附环丙沙星的影响 [J]. 环境化学, 2020, 39(11): 3153-3160. doi: 10.7524/j.issn.0254-6108.2019082802 LIU P, WANG H Y, WU X W, et al. Effects of particle size on the adsorption of ciprofloxacin on polystyrene microplastics [J]. Environmental Chemistry, 2020, 39(11): 3153-3160(in Chinese). doi: 10.7524/j.issn.0254-6108.2019082802
[24] LIU P, QIAN L, WANG H Y, et al. New insights into the aging behavior of microplastics accelerated by advanced oxidation processes [J]. Environmental Science & Technology, 2019, 53(7): 3579-3588. [25] 田世烜, 张萌, 陈亮, 等. 3种污泥对磺胺二甲基嘧啶的吸附性能 [J]. 环境工程学报, 2012, 6(3): 1020-1024. TIAN S (H /X), ZHANG M, CHEN L, et al. Adsorption characteristics of sulfamethazine by three kinds of sludge [J]. Chinese Journal of Environmental Engineering, 2012, 6(3): 1020-1024(in Chinese).
[26] 仉春华, 孙红杰, 冯福绿等. 活性污泥对2种喹诺酮类抗生素的吸附特征 [J]. 辽宁工程技术大学学报(自然科学版), 2021, 40(4): 360-366. ZHANG C H, SUN H J, CHEN F L, et al. Adsorption characters of two Quinolone antibiotics inactivated sludge [J]. Journal of Liaoning Technical University, 2021, 40(4): 360-366(in Chinese).
[27] 仇付国, 王肖倩, 童诗雨, 等. 给水厂污泥改性活性炭对硝酸根的吸附性能[J]. 应用化工, 2022, 51(2): 354-359. QIU F G, WANG X Q, TONG S Y, et al. The adsorption characteristics of nitrate on activated carbon modified by metals extracted from water treatment residual [J]. Applied Chemical Industry, 2022,51(2): 354-359 (in Chinese) .
[28] 张凌霄, 于洁, 吕阳, 等. 污泥基吸附剂对亚甲基蓝和环丙沙星的吸附性能研究 [J]. 宁波大学学报(理工版), 2021, 34(3): 47-53. ZHANG L X, YU J, LÜ Y, et al. Adsorption of methylene blue and ciprofloxacin by activated sludge-derived adsorbent [J]. Journal of Ningbo University (Natural Science & Engineering Edition), 2021, 34(3): 47-53(in Chinese).
[29] 郑红婷, 张秀霞, 钟哲森, 等. 石油污染土壤中漆酶活性的影响因素 [J]. 环境工程学报, 2017, 11(10): 5703-5707. doi: 10.12030/j.cjee.201611066 ZHENG H T, ZHANG X X, ZHONG Z S, et al. Influence factors of laccase activity in oil-contaminated soil [J]. Chinese Journal of Environmental Engineering, 2017, 11(10): 5703-5707(in Chinese). doi: 10.12030/j.cjee.201611066
[30] KEUM Y S, LI Q X. Fungal laccase-catalyzed degradation of hydroxy polychlorinated biphenyls [J]. Chemosphere, 2004, 56(1): 23-30. doi: 10.1016/j.chemosphere.2004.02.028 [31] 张阳. pH值及温度对杂色云芝漆酶活性的影响 [J]. 资源节约与环保, 2015(3): 86. doi: 10.3969/j.issn.1673-2251.2015.03.067 ZHANG Y. Effects of pH and temperature on laccase activity of Yunzhi versicolor [J]. Resources Economization & Environment Protection, 2015(3): 86(in Chinese). doi: 10.3969/j.issn.1673-2251.2015.03.067
[32] EICHLEROVÁ I, ŠNAJDR J, BALDRIAN P. Laccase activity in soils: Considerations for the measurement of enzyme activity [J]. Chemosphere, 2012, 88(10): 1154-1160. doi: 10.1016/j.chemosphere.2012.03.019 [33] MATHUR S P, 唐咏. 热带、亚热带和温带地区土壤酶在有机质降解中的作用 [J]. 土壤学进展, 1985(5): 20-23. MATHUR S P, TANG Y. The role of soil enzymes in the degradation of organic matter in tropical, subtropical and temperate regions [J]. Advances in Soil Science, 1985(5): 20-23(in Chinese).
[34] 梁小兵, 朱建明, 刘丛强, 等. 贵州红枫湖沉积物有机质的酶及微生物降解 [J]. 第四纪研究, 2003, 23(5): 565-572. doi: 10.3321/j.issn:1001-7410.2003.05.012 LIANG X B, ZHU J M, LIU C Q, et al. Enzymatic and microbial degradation of organic matter in Lake Hongfeng of Guizhou Province [J]. Quaternary Sciences, 2003, 23(5): 565-572(in Chinese). doi: 10.3321/j.issn:1001-7410.2003.05.012