红壤中La的生物富集及其对玉米幼苗生长影响研究

Through a pot culture lanthanum nitrate was applied to maize seedlings grown in a red loamy soil to investigate the physiological and toxic effects of added La on the growth of crop seedlings and La bioaccumulation to help understand the environmental chemistry behaviors of rare earth element as fertilizers in soils. Compared to the control, La concentrations in shoots and especially in roots of maize seedlings increased with an increase of La in the soil. Also, with added concentrations of La 〉 0.75 g La kg-1 soil and ≥ 0.05 g La kg^-1 soil, the dry weight of shoots and roots of maize seedlings was significantly reduced （P ≤ 0.05）, respectively, compared with the control. Additionally, La ≥0.5 g kg^-1 in the soil significantly inhibited （P ≤ 0.05） primary root elongation. Roots were more sensitive to La stress than shoots and thus could be used as a biomarker to La stress. Overall, in the red loamy soil studied, La had no significant beneficial effects on the growth of maize at the added La levels above 0.1 g kg^-1 soil.     

Mycoremediation of Potentially Toxic Trace Elements——a Biological Tool for Soil Cleanup: A Review

Anthropogenic and geogenic activities release potentially toxic trace elements (PTEs) that impact human health and the environment.Increasing environmental pollution stresses the need for environmentally friendly remediation technologies.Physico-chemical treatments are effective,but are costly and generate secondary pollution on-or off-site.Phytoremediation is a biological treatment that provides positive results for PTE eradication with few limitations.Mycoremediation,a type of bioremediation to use macrofungi (mushrooms) for PTE extraction from polluted sites,is the best option for soil cleanup.This review highlights the scope,mechanisms,and potentials of mycoremediation.Mushrooms produce a variety of extracellular enzymes that degrade polycyclic aromatic hydrocarbons (PAHs),polychlorinated biphenyls (PCBs),pesticides,dyes,and petroleum hydrocarbons into simpler compounds.Cadmium (Cd),lead (Pb),mercury (Hg),chromium (Cr),copper (Cu),zinc (Zn),and iron (Fe) have been effectively extracted by Phellinus badius,Amanita spissa,Lactarius piperatus,Suillus grevillei,Agaricus bisporous,Tricholoma terreum,and Fomes fomentarius,respectively.Mycoremediation is affected by environmental and genetic factors,such as pH,substrate,mycelium age,enzyme type,and ecology.The bioaccumulation factor (BAF) can make clear the effectiveness of a mushroom for the extraction of PTEs from the substrate.Higher BAF values of Cd (4.34),Pb (2.75),Cu (9),and Hg (95) have been reported for Amanita muscaria,Hypholoma fasciculare,Russula foetens,and Boletus pinophilus,respectively,demonstrating their effectiveness and suitability for mycoremediation of PTEs.     

蔬菜对多氯代有机污染物富集转移特征初探

采用野外调查采样和室内培养、分析相结合的方法,探讨蔬菜对多氯代有机污染物（PCOPs）的富集和转移特征。结果表明：不同旱地蔬菜对不同PCOPs的富集能力和转移能力各不相同,主要体现在叶菜类对六六六（HCB）的富集系数最高,根菜类对滴滴涕（DDT）类的转移系数最高等特点;不同盆栽蔬菜的富集和转移特点和旱地蔬菜的基本一致,且随着土壤受污染程度的加剧会导致其富集系数和转移系数降低,这与蔬菜生物量较小而影响其对PCOPs的富集和转移能力有关。研究结论可为了解PCOPs由土壤环境进入蔬菜体内及其在体内的转移提供科学依据。     

Use of tissue and sediment‐based threshold concentrations of polychlorinated biphenyls (PCBs) to protect juvenile salmonids listed under the US Endangered Species Act

• 1. Under the Endangered Species Act, the National Marine Fisheries Service has authority to protect listed species from any adverse actions that may jeopardize the population's ability to recover and increase to sustainable levels. Listed salmon species in the northwest United States are known to travel through urban areas in their migration from river to ocean. Species such as the chinook salmon (Oncorhynchus tshawytscha) often spend several weeks in these urban estuaries where they can be highly exposed to urban‐related contaminants that reside in the sediments and accumulate in their prey species. The concern is that these contaminants are bioaccumulated to levels that may impact the ability of individual salmon to grow and mature normally. This paper provides a framework for determining the tissue and sediment concentrations of polychlorinated biphenyls (PCBs) that are likely protective against adverse effects in listed salmonid species.
• 2. The relevant ecotoxicological literature was examined and 15 studies were selected that met the pre‐established criteria outlined here. For each study, the lowest tissue concentration (residue) of total PCBs associated with a biological response was selected. The tissue concentration associated with the 10th percentile of these 15 studies was chosen to represent the residue effect threshold (RET) above which wild juvenile salmonids would be expected to exhibit adverse sublethal effects from accumulated PCBs. This value (2.4 μg PCBs g^?1 lipid) is expressed in terms of the lipid‐normalized concentration because of the large effect lipid can have on the expressed toxicity and the substantial variability in lipid content observed in salmonids over their life cycle.
• 3. A sediment concentration that is expected to produce the RET was then determined using the biota‐sediment accumulation factor approach. The sediment effect threshold, which varies with the total organic carbon content in sediment, is the level above which adverse effects may be expected in juvenile salmonids due to accumulation of PCBs from environmental exposure. Bioaccumulation of PCBs was examined in one river system as a model for determining an appropriate bioaccumulation factor for wild juvenile chinook salmon.
• 4. Evaluation of exposure to potentially deleterious concentrations of PCBs based on tissue residues is the preferred approach; however, the sediment effect threshold may also be used in cases where bioaccumulation has been characterized in an estuary. The threshold values presented here are intended as interim guidelines that should be modified as more data become available. Additionally, because of the uncertainty around many of the factors and assumptions that comprise the single threshold effect values, it is recommended that future studies be employed to help determine a range of acceptable values that would afford protection under various environmental and biological conditions.

Published in 2002 by John Wiley & Sons, Ltd.     

不同污染背景生境中背角无齿蚌的重金属积累特征

以中国水产科学研究院淡水渔业研究中心南泉基地(无明显外源污染)、太湖梅梁湾(历史上污染较为严重)以及云南茈碧湖(高原洁净湖泊)生境中的背角无齿蚌(Anodonta woodiana)为对象,应用电感耦合等离子质谱仪(ICP-MS)分析了蚌样软组织中15种重金属(Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Mo、Ag、Cd、Ba、Tl和Pb)的积累特征.结果表明:南泉基地养殖蚌中Al、Cr、Mn、Fe、Ni、Cu、Zn、As、Cd和Ba的含量显著低于梅梁湾野生蚌(P＜0.05),茈碧湖野生蚌中Al、Mn、Ni、Cu、Zn、As、Cd、Ba和Pb的含量显著低于梅梁湾蚌样(P＜0.05),但前者Mo和Tl的含量显著高于后者(P＜0.05);南泉基地蚌样中Cr、Fe、Mo和Tl的含量显著低于茈碧湖蚌样(P＜0.05),而Cu、As和Pb的含量显著高于后者(P＜0.05).梅梁湾、南泉基地和茈碧湖蚌的金属污染指数(MPI)分别为11.1、1.8和1.0,显示出南泉基地养殖蚌重金属总体污染水平很低,与生活于洁净水体茈碧湖中蚌的情况相近,而远低于采自太湖梅梁湾蚌的水平.     

Growth and enzymatic activity of maize (Zea mays L.) plant: Solution culture test for copper dioxide nano particles

Copper (Cu) is an essential micronutrient for plants, which acts either as the metal component of enzymes or as a functional structural or a regulatory co-factor of a large number of enzymes. To understand the possible benefits of applying nanotechnology to agriculture, the first step should be to analyze penetration and transport of nano-particles in plants. The present study was conducted to test the hypothesis that copper nanoparticle would enter into the plant cell and govern the growth of maize plant.A solution culture experiment was conducted to investigate the effect of Cu nano-particles (<50nm) on the growth and enzymatic activity of maize (Zea mays L.) plant. Bioaccumulation of Cu nano-particles in plant was also investigated. Results showed that Cu nano-particles can enter into the plant cell through roots and leaves. Bioaccumulation increased with increasing concentration of Cu nano-particles (NPs), and agglomeration of particles was observed in the cells using transmission-electron microscopy. Application of Cu nano-particles through solution culture as well as spray enhanced the growth (51%) of maize plant in comparison to control. The different enzymatic activities like glucose-6-phosphate dehydrogenase, succinate dehydrogenase, superoxide dismutase, catalase, andguaiacol peroxidase were studied to find a possible pathway through which NPs may affect the enzymatic activity of plant. Amongst the enzymes, the activity of glucose-6-phosphate dehydrogenase was highly influenced by copper oxide (CuO)nano-particles application by spray as well as in solution. Experimental results revealed that CuOnano-particles affected the pentose phosphate pathway of maize plant. The obtained experimental results provided conclusive evidence to indicate that the nano-particles considered under this study could enter into the plant cell, easily be assimilated by plants and also enhanced its growth by regulating the different enzyme activities.     

空心莲子草对污泥重金属的响应与吸附效应

植物修复（Phytoremediation）是解决越来越突出的重金属污染问题的一种较好的方法,已成为生态学和环境学研究的重要课题,而植物对重金属的响应和吸附效应是该问题的科学基础。为此,本研究采用盆栽方法,设定污泥与沙壤土的不同体积配比（无污泥、5%污泥、10%污泥和20%污泥）作为生长基质,测定在含不同重金属的基质中生长不同时间（3-6月）的空心莲子草（Alternanthera philoxeroides）叶片的生理指标[叶绿素含量、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性]和在含重金属基质中生长6个月后的空心莲子草根、茎、叶中重金属元素（Cd、Cr、Mn、Ni、Pb、Cu、Zn）含量。结果表明,空心莲子草叶片中叶绿素含量总体上随生长基质中污泥体积比例升高而升高;空心莲子草叶片中SOD活性、POD活性总体随生长基质中污泥体积比例升高而升高,但在含重金属的生长基质中生长5个月后,叶绿素含量、SOD活性和POD活性均明显下降;在各处理下,空心莲子草对Mn、Ni、Cr、Pb、Cu和Zn的吸收主要分布在叶片,且空心莲子草的转运系数大于1。研究结果说明,空心莲子草对污泥重金属有较好的耐受性,且转运系数大于1。虽然该植物根、茎、叶的富集系数均小于1,不属于超富集植物,但在受重金属污染的土壤植物修复中仍有一定的参考作用。     

黑曲霉对重金属Cu（Ⅱ）和Zn（Ⅱ）的抗性及富集特性

以黑曲霉(Aspergillus niger)为实验菌株,探讨不同pH值、重金属离子初始浓度、孢子液接种量和重金属离子共存对菌体生长量和富集能力的影响。结果表明:Cu(Ⅱ)和Zn(Ⅱ)对黑曲霉的最低抑菌浓度分别为250、700mg·L-1;菌株最佳生长和富集条件为pH5.0、孢子液体积1mL,黑曲霉对Cu(Ⅱ)和Zn(Ⅱ)的富集分别在4d和5d达到平衡。在重金属共存系统中,Cu(Ⅱ)/Zn(Ⅱ)浓度越高,黑曲霉对Cu(Ⅱ)/Zn(Ⅱ)富集能力越强;Cu(Ⅱ)和Zn(Ⅱ)的富集量分别在其浓度为150、250mg·L-1时达到最大(8.89、22.80mg·g-1)。采用扫描和透射电镜观察富集前后菌体表面形态和内部结构变化,表明菌体生长受重金属毒害作用可能破坏菌丝表面结构,A.niger富集Cu(Ⅱ)和Zn(Ⅱ)由表面吸附和胞内富集两部分组成,Zn(Ⅱ)作用下菌丝的完整性较好,菌株对Zn(Ⅱ)具有较强的抗性和适应能力。     

蟛蜞菊对污泥重金属的响应、吸收与富集作用

植物修复(phytoremediation)是解决越来越突出的重金属污染问题的一种较好方法,成为生态学和环境学研究的重要课题。而植物对重金属的响应、吸收与富集作用是该课题的科学基础。为此,本研究采用盆栽实验方法,设定污泥与砂壤土的不同体积配比(0%污泥、10%污泥、20%污泥和40%污泥)作为生长基质,测定在含重金属基质中生长不同时间(3、4、5和6个月)的蟛蜞菊(Wedelia trilobata)叶片的生理指标(叶绿素含量、POD活性、SOD活性)和在含重金属基质中生长6个月后的蟛蜞菊根、茎、叶中重金属(Cd、Cr、Mn、Ni、Pb、Cu和Zn)含量。研究结果显示,总体上,蟛蜞菊叶片中叶绿素含量随着生长基质中污泥体积比例升高而显著(P<0.05)升高;随着生长基质中污泥体积比例升高,蟛蜞菊叶片中SOD活性、POD活性变化显著(P<0.05),在含重金属的生长基质中生长5个月后,SOD活性和POD活性都显著(P<0.05)下降;在含较高浓度的污泥重金属的生长基质(20%污泥和40%污泥处理)中生长6个月后,蟛蜞菊叶片中Ni、Cu、Cr含量较高。研究结果说明污泥对蟛蜞菊叶绿素含量有促进作用;蟛蜞菊对污泥重金属有较强的耐受性,叶片对Ni、Cu、Cr具有超富集作用。     

Environmental Arsenic and Selenium Contamination and Approaches Towards Its Bioremediation Through the Exploration of Microbial Adaptations: A Review

Bioaccumulation of selenium and arsenic resulting from geogenic activities and aggravated by anthropogenic actions has now become a serious environmental issue. Different parts of the world are experiencing issues of selenium and arsenic contamination, especially in soil and groundwater. The present selenium and arsenic contamination scenario has been well represented in contemporary literature, and there are an array of remediation techniques targeting the decontamination of environmental contamination. The use of microbe-mediated remediation of selenium and arsenic contamination is gaining scientific attention for sustainable environmental bioremediation. The present review elucidates the different aspects of selenium and arsenic contamination, bioaccumulation, and bioremediation with implications for successful decontamination of these heavy metals.