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近年来,在环境中不断增加的塑料制品经不断碎裂、分化为粒径微小、难降解的微塑料(MPs), 广泛分布于土壤、水环境、大气[1 − 2]. Feng、Akdogan 等认为,MPs比表面积大、附着位点多,对土壤酸碱度、持水量、孔隙度、湿度、团聚结构、生物量、酶活性等均产生较为严重的不良作用,对植物、动物的生长产生毒性作用[3 − 4]. 胡晓婧认为,施用聚苯乙烯后土壤可溶性有机碳、氮、磷增加,微生物代谢通路会做出响应,种植的大豆干重降低、根直径减小[5]. 此外,国外学者发现微塑料引起土壤的容重、团聚体、持水性、微生物群落多样性等理化特性和生物学性质出现较大的变化,影响某些降解功能基因表达,加快了土壤中氮循环、碳循环,增强了对多种污染物吸附性,调控能力受到一定的影响,损害了生态环境健康[6]. 此外,作为新兴污染物的抗生素对生态环境、人类健康带来的潜在危害也是当下需要特别重点关注和彻底解除[7]. 抗生素在预防和治疗人类和动物疾病的同时,也残留在污水处理厂终端、养殖场、灌溉沟渠、垃圾处理厂等. 其中,聚乙烯(PE)是无味、无毒、耐侵蚀、电绝缘性高、应用性广的塑料产品. 四环素(TC)、环丙沙星( CIP )是目前在治疗多种疾病中应用较广、较多的药物,但是也可能影响酶活性、传递抗性基因,危害生命安全[8 − 9]. 进入土壤中的抗生素影响呼吸、矿化、硝化作用,并通过基因突变、基因转移、土著菌的变性,对生态环境、人类的造成不可逆转危害,迫切需要加大力度进行综合处理[10 − 11]. 已报道的研究表明,MPs和抗生素的复合污染产生的生态效应更为复杂、危害更为严重. 周曙仡聃等认为MPs改变ARGs的丰度、分布[12]. 目前有关MPs与抗生素的复合污染研究多集中于水培试验所获得研究结论,而对土壤的联合污染研究较少[13],分子水平的研究更为罕见,亟需从分子水平上阐明微塑料—抗生素在土壤富集、吸附、降解、响应效应[14].
基于项目组前期研究工作的基础上,选择在土壤中普遍存在且检出率较高的PE、TC、CIP为研究对象,开展复合污染对土壤的理化特性、酶活性、抗生素残留、四环素抗性菌( TC resistant bacteria,TCRB)抗性、环丙沙星抗性菌(CIP resistant bacteria,CIPRB)抗性、抗生素抗性基因(antibiotic resistance genes,ARGs)的研究,进一步探明了MPs对抗生素残留、ARGs传播、微生物群落演化特征等潜在影响,以期为消减污染物的危害、构建综合智能修复体系提供依据.
微塑料和多种抗生素胁迫下土壤环境因子的响应特性
Response characteristics of soil environmental factors under the stress of microplastics and antibiotics
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摘要: 为了深入探究微塑料(microplastics,MPs)、抗生素胁迫下土壤环境因子产生的响应特性,以聚乙烯(polyethylene,PE)、四环素 (tetracycline,TC)、环丙沙星(ciprofloxacin,CIP)为研究对象,通过单独、联合施用到土壤中4周后,开展了土壤的理化性质、酶活性、抗生素残留、抗生素抗性菌(antibiotics resistant bacteria,ARB)抗性、抗生素抗性基因(antibiotic resistance genes,ARGs)、微生物群落的多样性等方面研究. 结果显示,施用MPs与抗生素的容重比对照组分别增大了12.3%、16.9%、21.8%. 有机质含量由39.96 g·kg−1变化为53.21 g·kg−1,与对照组相比分别增大了9.16%、12.39%、14.09%、18.47%、32.03%、33.16%、36.04%. 阳离子交换量由对照组的44.36 cmol·kg−1显著变化为62.45 cmol·kg−1,与对照组相比分别增大了24.06%、30.09%、33.97%、36.49%、47.14%、50.93%、56.1%. 实验各组pH值在7.58 — 8.12之间变化. 实验各组的过氧化氢酶含量分别为1.653、 1.559、1.421、1.486、1.376、1.545、1.524、1.453 IU·g-1;脲酶含量分别为89.56、78.32、64.65、66.79、57.27、72.31、71.26、61.56 IU·g-1;蔗糖酶含量分别为158.69、149.61、134.56、131.87、123.65、137.26、136.83、126.34 IU·g−1. MPs-TC-CIP组的过氧化氢酶活性、脲酶活性、蔗糖酶活性分别下降12.1%、32.3%、26.7%. MPs-TC、MPs-CIP组与TC、CIP实验组相比,抗生素残留量有所降低,分别为187.1%、189.3%;MPs-TC-CIP实验组的抗生素残留则低于单一施用CIP、TC组,分别为182.6%、178.7%. 筛选的TC抗性菌(TC resistant bacteria,TCRB)和CIP抗性菌(CIP resistant bacteria,CIPRB)的抗性增加2倍以上. MPs-TC-CIP组与对照组相比,tet W、tet O的相对丰度比值分别为1.82、1.78;qnr A 、qnr S的相对丰度比值分别为1.68、1.71. 各组中相对丰度较高菌群依次为变形菌(Proteobacteria),放线菌(Actinobacteria)、酸杆菌(Acidobacteria)、芽单胞菌(Gemmatimonadetes)、厚壁菌(Fimicutes). 施用抗生素、MPs后Proteobacteria、Actinobacteria相对丰度增加、myxococcus相对丰度减少. 研究结果表明,施用MPs能促进抗生素的富集;在共同胁迫下,对土壤理化特性和生物特性影响更为显著,进一步探明了MPs对抗生素残留、ARGs传播、微生物群落演化特征等潜在影响,以期为消减污染物的危害、构建综合智能修复体系提供依据.Abstract: In order to investigate the effects of microplastics and antibiotics on the response characteristics of soil environmental factors, MPs, Tetracycline (TC) and Ciprofloxacin (CIP) were applied into soil for 4 weeks separately or jointly. In this experiment, a large number of studies were carried out, such as the physicochemicalof soil, enzyme activity, antibiotic residues, resistance of antibiotics resistant bacteria (ARB), the antibiotic resistance genes (ARGs) and the diversity of microbial community. As a results, the unit weight of soil were increased 12.3%, 16.9% and 21.8%, respectively. Compared with the control group, the content of organic matter were changed from 39.96 g·kg−1 to 53.21 g·kg−1 by PE and antibiotic. They were increased 9.16%, 12.39%, 14.09%, 18.47%, 32.03%, 33.16% and 36.04%, respectively. So the cation exchange capacity was significantly changed from 44.36 cmol·kg−1 to 62.45 cmol·kg−1, and they were increased 24.06%, 30.09%, 33.97%, 36.49%, 47.14%, 50.93% and 56.1%, respectively. The pH of each group varied from 7.58 to 8.12. The catalase of each group were 1.653, 1.559, 1.421, 1.486, 1.376, 1.545, 1.524, 1.453 IU·g−1, respectively. The urease activity of soil was 89.56, 78.32, 64.65IU·g−1, 66.79, 1.57.27, 72.3, 71.26 and 61.56 IU·g−1, respectively. The sucrase activities were 158.69, 149.61, 134.56, 131.87, 123.65, 137.26 , 136.83 and 126.34 IU·g−1, respectively. The activity of catalase, urease and sucrase with MPs and two antibiotics were reduced 12.1%, 32.3% and 26.7%, respectively. Compared with the control group, the residues of antibiotics were 187.1% and 189.3% by MPs-TC and MPs-CIP, respectively.Additionally,they were lower than the control group, 182.6% and 178.7% by MPs-TC-CIP, respectively. The relative abundance ratios of tet W and tet O were 1.82 and 1.78, respectively. And the relative abundance ratios of qnr A and qnr S were 1.68 and 1.71, respectively. The relative abundance of microbial community were followed by Proteobacteria, Actinobacteria, Acidobacteria, Gemmatimonadetes and Fimicutes. After the application of antibiotics and MPs, the relative abundance of Proteobacteria and Actinobacteria were increased, while the relative abundance of Myxococcus were decreased.The results showed that MPs could promote the enrichment of antibiotics.Under co-stress with MPs-TC-CIP, the effect of physical, chemical and biological characteristics on soil were more significant than the MPs,TC, and CIP alone or mixed. Furtherly, the potential effects of MPs on were explored , such as antibiotic residues, transmission of ARGs and the microbial community diversity, which were laid a foundation for reducing the harm of pollutants and building a comprehensive intelligent remediation system.
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Key words:
- microplastics /
- antibiotics /
- antibiotics resistant bacteria /
- enzyme activity /
- microbial diversity
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表 1 实验分组设计
Table 1. Experimental group design
组别
Group添加物
Additives备注
NoteCK 未添加 将PE、TC、CIP配制浓度为1.0 g·kg−1,投加到土壤4 周,每组随机分离10株抗性菌,进行土壤的理化特性、抗生素残留、ARB、ARGs、微生物群落等检测. M1 PE M2 TC M3 CIP M4 TC+CIP M5 PE+TC M6 PE+CIP M7 PE+TC+CIP -
[1] 姬庆松, 孔祥程, 王信凯, 等. 环境微塑料与有机污染物的相互作用及联合毒性效应研究进展[J]. 环境化学, 2022, 41(1): 70-82. doi: 10.7524/j.issn.0254-6108.2020090303 JI Q S, KONG X C, WANG X K, et al. The interaction and combined toxic effects of microplastics and organic pollutants in the environment: A review[J]. Environmental Chemistry, 2022, 41(1): 70-82(in Chinese). doi: 10.7524/j.issn.0254-6108.2020090303
[2] 郝爱红, 赵保卫, 张建, 等. 土壤中微塑料污染现状及其生态风险研究进展[J]. 环境化学, 2021, 40(4): 1100-1111. doi: 10.7524/j.issn.0254-6108.2020083102 HAO A H, ZHAO B W, ZHANG J, et al. Research progress on pollution status and ecological risk of microplastics in soil[J]. Environmental Chemistry, 2021, 40(4): 1100-1111(in Chinese). doi: 10.7524/j.issn.0254-6108.2020083102
[3] FENG S S, LU H W, TIAN P P, et al. Analysis of microplastics in a remote region of the Tibetan Plateau: Implications for natural environmental response to human activities[J]. Science of the Total Environment, 2020, 739: 140087. doi: 10.1016/j.scitotenv.2020.140087 [4] AKDOGAN Z, GUVEN B. Microplastics in the environment: A critical review of current understanding and identification of future research needs[J]. Environmental Pollution, 2019, 254: 113011. doi: 10.1016/j.envpol.2019.113011 [5] 胡晓婧, 刘俊杰, 王浩, 等. 微塑料污染对土壤环境质量和微生物生态学特性的影响研究进展[J]. 土壤通报, 2021, 52(6): 1479-1485. doi: 10.19336/j.cnki.trtb.2021022501 HU X J, LIU J J, WANG H, et al. Impacts of microplastics on soil environmental quality and microbial ecological characteristics: A review[J]. Chinese Journal of Soil Science, 2021, 52(6): 1479-1485(in Chinese). doi: 10.19336/j.cnki.trtb.2021022501
[6] YAN Y Y, CHEN Z H, ZHU F X, et al. Effect of polyvinyl chloride microplastics on bacterial community and nutrient status in two agricultural soils[J]. Bulletin of Environmental Contamination and Toxicology, 2021, 107(4): 602-609. doi: 10.1007/s00128-020-02900-2 [7] 金明兰, 王悦宏, 郝新瑞, 等. 四环素类和磺胺类双重抗生素抗性菌的特性[J]. 科学技术与工程, 2020, 20(31): 13067-13071. doi: 10.3969/j.issn.1671-1815.2020.31.058 JIN M L, WANG Y H, HAO X R, et al. Characteristics of tetracycline and sulfonamide double antibiotics resistant bacteria, resistance genes in sewage treatment plants[J]. Science Technology and Engineering, 2020, 20(31): 13067-13071(in Chinese). doi: 10.3969/j.issn.1671-1815.2020.31.058
[8] 金明兰, 孟庆玲, 赵玉鑫, 等. 养殖场空气中E. coli磺胺类抗生素的抗性[J]. 环境化学, 2017, 36(3): 472-479. doi: 10.7524/j.issn.0254-6108.2017.03.2016070102 JIN M L, MENG Q L, ZHAO Y X, et al. Characterization of sulfa antibiotics resistance of E. coli from the air of poultry farms[J]. Environmental Chemistry, 2017, 36(3): 472-479(in Chinese). doi: 10.7524/j.issn.0254-6108.2017.03.2016070102
[9] LI S M, LI J, LI Z, et al. Toxic effects of norfloxacin in soil on fed and unfed Folsomia candida (Isotomidae: Collembola) and on gut and soil microbiota[J]. The Science of the Total Environment, 2021, 788: 147793. doi: 10.1016/j.scitotenv.2021.147793 [10] LYU J, YANG L S, ZHANG L, et al. Antibiotics in soil and water in China-a systematic review and source analysis[J]. Environmental Pollution (Barking, Essex: 1987), 2020, 266(Pt 1): 115147. [11] SCARIA J, ANUPAMA K V, NIDHEESH P V. Tetracyclines in the environment: An overview on the occurrence, fate, toxicity, detection, removal methods, and sludge management[J]. The Science of the Total Environment, 2021, 771: 145291. doi: 10.1016/j.scitotenv.2021.145291 [12] 周曙仡聃, 朱永官, 黄福义. 微塑料对海水抗生素抗性基因的影响[J]. 环境科学, 2021, 42(8): 3785-3790. doi: 10.13227/j.hjkx.202101009 ZHOU S, ZHU Y G, HUANG F Y. Microplastic-induced alterations to antibiotic resistance genes in seawater[J]. Environmental Science, 2021, 42(8): 3785-3790(in Chinese). doi: 10.13227/j.hjkx.202101009
[13] 刘璐, 孙启智, 刘章华, 等. 水环境中微塑料的迁移及其与有机污染物的复合毒性效应研究进展[J]. 环境化学, 2022, 41(5): 1504-1514. doi: 10.7524/j.issn.0254-6108.2021070904 LIU L, SUN Q Z, LIU Z H, et al. Migration of microplastics and their combined toxic effects with organic pollutants in water environment: A review[J]. Environmental Chemistry, 2022, 41(5): 1504-1514(in Chinese). doi: 10.7524/j.issn.0254-6108.2021070904
[14] 喻红霞, 刘晓薇, 汪慧香, 等. 微塑料生物膜11种AHLs类群体感应信号分子测定及其分泌特征[J]. 环境化学, 2022, 41(3): 785-792. doi: 10.7524/j.issn.0254-6108.2021101206 YU H X, LIU X W, WANG H X, et al. Determination and secretion characteristics of 11 N-acyl-homoserine lactones signal molecules of quorum sensing in microplastic biofilms[J]. Environmental Chemistry, 2022, 41(3): 785-792(in Chinese). doi: 10.7524/j.issn.0254-6108.2021101206
[15] 赵鑫宇, 剧泽佳, 陈慧, 等. 石家庄市土壤中喹诺酮类抗生素空间分布特征及其与微生物群落相关性[J]. 环境科学, 2022, 43(9): 4684-4696. doi: 10.13227/j.hjkx.202112104 ZHAO X Y, JU Z J, CHEN H, et al. Spatial distribution of quinolone antibiotics and its correlation relationship with microbial community in soil of Shijiazhuang City[J]. Environmental Science, 2022, 43(9): 4684-4696(in Chinese). doi: 10.13227/j.hjkx.202112104
[16] LI Y T, WANG J, YANG S, et al. Occurrence, health risks and soil-air exchange of phthalate acid esters: A case study in plastic film greenhouses of Chongqing, China[J]. Chemosphere, 2021, 268: 128821. doi: 10.1016/j.chemosphere.2020.128821 [17] WANG J, LIU X H, DAI Y X, et al. Effects of co-loading of polyethylene microplastics and ciprofloxacin on the antibiotic degradation efficiency and microbial community structure in soil[J]. Science of the Total Environment, 2020, 741: 140463. doi: 10.1016/j.scitotenv.2020.140463 [18] ZHAN R , FENG J , HUANG J , et al. Reponses of microbial community and antibiotic resistance genes to the selection pressures of ampicillin, cephalexin and chloramphenicol in activated sludge reactors [J] . Science of the Total Environment, 2020, 755(2): 142632. [19] ZHANG R, XU X, JIA D, et al. Sediments alleviate the inhibition effects of antibiotics on denitrification: Functional gene, microbial community, and antibiotic resistance gene analysis [J] . Science of the Total Environment, 2021, 150092. [20] 田其凡, 何玘霜, 陆安祥, 等. 农田土壤抗生素抗性基因与微生物群落的关系 [J] . 环境化学, 2020, 39(5): 192-201. doi: 10.7524/j.issn.0254-6108.2019060602 TIAN Q F, HE Q S, LU A X, et al. Relationship between antibiotic resistance genes and microbial communities in farmland soil [J]. Environmental Chemistry, 2020, 39 (5): 192-201 (in Chinese) . doi: 10.7524/j.issn.0254-6108.2019060602
[21] ZANG H D, ZHOU J, MARSHALL M R, et al. Microplastics in the agroecosystem: Are they an emerging threat to the plant-soil system?[J]. Soil Biology and Biochemistry, 2020, 148: 107926. doi: 10.1016/j.soilbio.2020.107926 [22] AWET T T, KOHL Y, MEIER F, et al. Effects of polystyrene nanoparticles on the microbiota and functional diversity of enzymes in soil[J]. Environmental Sciences Europe, 2018, 30(1): 11. doi: 10.1186/s12302-018-0140-6 [23] 何玉洁, 周凯萍, 饶怡璇, 等. 土壤中抗生素的环境风险及污染土壤的生物修复技术[J]. 生物工程学报, 2021, 37(10): 3487-3504. doi: 10.13345/j.cjb.210421 HE Y J, ZHOU K P, RAO Y X, et al. Environmental risks of antibiotics in soil and the related bioremediation technologies[J]. Chinese Journal of Biotechnology, 2021, 37(10): 3487-3504(in Chinese). doi: 10.13345/j.cjb.210421
[24] ZHOU Y F, HE G, JIANG X L, et al. Microplastic contamination is ubiquitous in riparian soils and strongly related to elevation, precipitation and population density[J]. Journal of Hazardous Materials, 2021, 411: 125178. doi: 10.1016/j.jhazmat.2021.125178 [25] 鞠志成, 金德才, 邓晔. 土壤中塑料与微生物的相互作用及其生态效应[J]. 中国环境科学, 2021, 41(5): 2352-2361. doi: 10.3969/j.issn.1000-6923.2021.05.043 JU Z C, JIN D C, DENG Y. The interaction between plastics and microorganisms in soil and their ecological effects[J]. China Environmental Science, 2021, 41(5): 2352-2361(in Chinese). doi: 10.3969/j.issn.1000-6923.2021.05.043
[26] 胡志娥, 肖谋良, 王双, 等. 地膜覆盖对农田土壤养分和生态酶计量学特征的影响[J]. 环境科学, 2022, 43(3): 1649-1656. doi: 10.13227/j.hjkx.202107005 HU Z E, XIAO M L, WANG S, et al. Effects of plastic mulch film on soil nutrients and ecological enzyme stoichiometry in farmland[J]. Environmental Science, 2022, 43(3): 1649-1656(in Chinese). doi: 10.13227/j.hjkx.202107005
[27] KWAK J I, AN Y J. Microplastic digestion generates fragmented nanoplastics in soils and damages earthworm spermatogenesis and coelomocyte viability[J]. Journal of Hazardous Materials, 2021, 402: 124034. doi: 10.1016/j.jhazmat.2020.124034 [28] 周雨婷. 中国农田土壤中抗生素抗性基因分布及典型污染物浓度特征、对其影响与风险评估[D]. 杭州: 浙江大学, 2020. ZHOU Y T. Distribution of antibiotic resistance genes and concentration characteristics, influence on antibiotic resistance genes, and risk assessments of typical pollutants in agricultural soils in China[D]. Hangzhou: Zhejiang University, 2020(in Chinese).
[29] FEI Y F, HUANG S Y, ZHANG H B, et al. Response of soil enzyme activities and bacterial communities to the accumulation of microplastics in an acid cropped soil[J]. Science of the Total Environment, 2020, 707: 135634. doi: 10.1016/j.scitotenv.2019.135634 [30] ZHANG L L, ZHANG C, LIAN K T, et al. Effects of chronic exposure of antibiotics on microbial community structure and functions in hyporheic zone sediments[J]. Journal of Hazardous Materials, 2021, 416: 126141. doi: 10.1016/j.jhazmat.2021.126141 [31] CHEN H P, WANG Y H, SUN X, et al. Mixing effect of polylactic acid microplastic and straw residue on soil property and ecological function[J]. Chemosphere, 2020, 243: 125271. doi: 10.1016/j.chemosphere.2019.125271 [32] 李嘉, 余松国, 沈林恩, 等. 微塑料对土壤吸附土霉素的影响初探[J]. 环境化学, 2021, 40(10): 3133-3143. doi: 10.7524/j.issn.0254-6108.2020101504 LI J, YU S G, SHEN L N, et al. Influence of microplastics on sorption behaviors of oxytetracycline onto soils: A preliminary study[J]. Environmental Chemistry, 2021, 40(10): 3133-3143(in Chinese). doi: 10.7524/j.issn.0254-6108.2020101504
[33] GAO B, YAO H Y, LI Y Y, et al. Microplastic addition alters the microbial community structure and stimulates soil carbon dioxide emissions in vegetable-growing soil[J]. Environmental Toxicology and Chemistry, 2021, 40(2): 352-365. doi: 10.1002/etc.4916 [34] 脱霞霞. 环丙沙星对土壤抗性基因和微生物群落的影响[D]. 杨凌: 西北农林科技大学, 2018. TUO X X. Effect of ciprofloxacin on diversity of resistance genes and bacterial communities in soil[D]. Yangling: Northwest A & F University, 2018(in Chinese).