Multivariate characterization of elements accumulated in Wolfiporia extensa mushroom from Yunnan province of China

ABSTRACT

Dried sclerotia of Wolfiporia extensa have been used as medicine in Asia from Eastern Han Dynasty, and also used as traditional snack called “fulingjiabing” in Beijing, China. In this paper, 18 macro and trace elements (Ag, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Li, Mn, Ni, Pb, Rb, Se, Sr, V, and Zn) in both flesh and peel of Wolfiporia extensa from seven sites of Yunnan province in China were determined by inductively coupled plasma mass spectrometer. The average recovery rates of certified reference materials for GBW10015 (spinach leaves) ranged from 90.5 to 113%, for GBW10028 (citrus leaves) from 92.8 to 106%, and for GBW07603 (bush branch and leaves) from 83.3 to 114.6%. Generally speaking, the concentration of all elements determined was at common level. The results of this survey indicate that mineral compositions in peel were higher than in flesh. In peel, the contents of investigated trace metals in mushroom samples were found to be in the range of 1,660–13,400 µg·g^?1 dry matter (dm) for Fe and 29.6–710 µg·g^?1 dm for Mn. The mean contents of Cr, Cu, Rb, V, and Zn in peel were between 10 and 20 µg·g^?1 dm, followed by As, Co, Li, Ni, Pb, Se, and Sr with mean contents between 1 and 10 µg·g^?1 dm, while Ag, Cd, and Cs had mean contents of <1 µg·g^?1 dm. In flesh, the concentration of Fe was in the range of 54–900 µg·g^?1 dm, and it was 1.5–49 µg·g^?1 dm for Mn, followed by Ba, Cu, Rb, and Zn in the range of 1 to 10 µg·g^?1 dm, while for Ag, As, Cd, Co, Cr, Cs, Li, Ni, Pb, Se, Sr, and V it was <1 µg·g^?1 dm. The concentration of toxic elements, such as As, Cd, and Pb, in both flesh and peel was below the permissible limits of World Health Organization. However, As and Pb contents in peel were higher than the limits permitted in the Chinese Pharmacopoeia. The results of principal component analysis showed that the flesh of Wolfiporia extensa from all the seven sites of the Yunnan province tend to cluster together, most probably because the origin of mineral elements in both flesh and peel is wood substrate (old and dead pine trees).     

Inorganic elemental concentrations in birch bolete mushroom (Leccinum scabrum) and top soil: contamination profiles,bioconcentation and annual variations

Abstract

Analysis of inorganic and organic contaminants in foodstuffs aids in understanding the human exposure to these compounds via consumption. In this study, an edible mushroom species (Leccinum scabrum) and top soil samples were analysed for essential and toxic substances including phosphorus and inorganic elements over a period of three fruiting seasons. Analysis of silver (Ag), aluminium (Al), barium (Ba), calcium (Ca), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), phosphorus (P), lead (Pb), rubidium (Rb), strontium (Sr) and zinc (Zn) in mushrooms and topsoil were performed using inductively coupled plasma optical emission spectroscopy (ICP-OES) with ultrasonic cross flow nebulizer. Total mercury was determined by cold-vapour atomic absorption spectroscopy (CV-AAS). The results exhibited wide variation in concentrations of metals between soil and mushroom (cap and stipes) during three fruiting seasons. Positive bioconcentration factors (BFCs) indicate on bioaccumulation of several metals including, Cd, Cu, Hg, K, Mg, Na, P, Rb and Zn in caps and stipes of fruitbodies of this mushroom, while other metals such as Al, Ba, Ca, Co, Fe, Mn, Ni, Pb and Sr were not exhibiting significant positive BFCs. Over a period studied, the caps were characterised by different (p?<?0.05) concentrations of Al, Co, Cu, Hg, Mn, Ni, P, Pb and Sr. Contamination profiles, temporal fluctuations, BCFs should be taken into consideration when assessing the nutritional value of this mushroom.     

In-situ synthesis of TiO2 rutile/anatase heterostructure by DC magnetron sputtering at room temperature and thickness effect of outermost rutile layer on photocatalysis

TiO_2 rutile/anatase heterostructure thin films with varying rutile thickness have been in-situ synthesized via DC magnetron sputtering with Ar gas at room temperature. The crystal texture, surface morphology, energy gap and optical properties of the films have been investigated by X-ray diffraction meter, grazing incidence X-ray diffraction meter, Raman spectroscopy, scanning electron microscopy, and UV–visible spectrophotometer, which indicates that the rutile/anatase heterostructure films are successfully fabricated. The further degradation experiments display that the photocatalytic activity can be dramatically affected by the thickness of the outmost rutile layer and the 100 nm thickness exhibits the best performance in all of the TiO_2 thin films. With the increase of the outmost rutile layer, the optical band gap of TiO_2 film displays a systematic decrease slightly. However,the change in photocatalytic activity does not coincide with that in the band gap. The photoresponse and electrochemical properties of the thin films have been characterized to understand the mechanism of the varied photocatalytic activity.     

锑胁迫下丛枝菌根真菌对玉米生长与锑吸收及抗氧化酶的影响

为了探讨AM(arbuscular mycorrhizal,丛枝菌根)真菌在Sb(锑)胁迫下对农作物生长及吸收Sb的影响,采用盆栽试验研究了在不同Sb添加量[即w(Sb)分别为0、500、1 000 mg/kg]下,接种AM真菌对玉米植株生物量以及N、P和Sb的吸收、膜脂过氧化[MDA(丙二醛)]和抗氧化酶活性的影响.结果表明:随着土壤中Sb添加量的增加,玉米植株的生物量、w(TN)和w(TP)均呈显著下降趋势,植株体内的w(Sb)和Sb积累量、MDA含量、CAT(过氧化氢酶)以及POD(过氧化酶)活性均显著上升.与未接种组相比,接种AM真菌显著促进了玉米植株的生长,提高了玉米植株地上部分的w(TN)和w(TP).在3个Sb添加量处理下,接种显著增加了玉米植株地下部分的w(Sb)、地上和地下部分的Sb积累量以及地上部分的CAT活性,增幅分别为8.90%~23.30%、18.87%~28.37%、27.68%~78.95%及14.92%~88.52%;同时,接种降低了玉米植株中Sb的转运率、玉米植株地上部分的w(Sb)和MDA含量,在1000 mg/kg Sb添加量下差异达显著水平,三者分别降低了36.35%、22.81%和24.29%.研究显示,在Sb污染环境下,接种AM真菌能够减轻玉米植株膜脂过氧化程度,在提高玉米植株地下部分w(Sb)的同时,也会降低Sb向地上部分的转运,减轻Sb对玉米的毒害作用.      

镧-铅复合污染下AM真菌对玉米生长和镧、铅吸收的影响

采用温室盆栽试验的方法,模拟不同程度的镧-铅复合污染土壤(50、200、800 mg·kg~(-1)),研究接种丛枝菌根(arbuscular mycorrhizal,AM)、真菌Claroideoglomus etunicatum(CE)和Rhizophagus intraradices(RI)对玉米(Zea mays L.)菌根侵染率、生物量、矿质营养元素吸收、C∶N∶P生态化学计量比、稀土镧(La)和重金属铅(Pb)吸收、转运的影响,旨在为稀土-重金属复合污染土壤的治理和修复提供科学依据.结果表明,AM真菌CE和RI均与玉米建立了共生关系,平均菌根侵染率为26.7%~95.8%;随着La-Pb复合污染含量的增加,玉米植株菌根侵染率、地上部和根部生物量以及N、P、K、Ca、Mg这5种矿质营养元素含量显著降低,而玉米植株C∶P和N∶P以及地上部和根部La、Pb含量显著增加.接种2种AM真菌使玉米植株生物量显著提高了17.8%~158.9%,地上部和根部P含量显著提高了24.5%~153.8%,降低了C∶P和N∶P,符合生长速率假设.在3种程度La-Pb复合污染含量土壤上,AM真菌使玉米植株根部Pb含量显著增加了51.3%~67.7%,地上部Pb含量显著降低了16.0%~67.7%,Pb从玉米根部向地上部的转运率降低了31.5%~54.7%;同时,接种AM真菌显著增加了轻度LaPb复合污染土壤上玉米植株的La含量,在中度La-Pb复合污染土壤上却显著减少了玉米地上部的La含量,增加了玉米根部的La含量,抑制了La从根部向地上部的转运,重度La-Pb复合污染土壤上均没有显著影响.试验结果初步证明,AM真菌具有促进稀土-重金属复合污染土壤植物修复的潜力,对于稀土-重金属复合污染土壤生态系统的植被恢复具有潜在应用价值.     

Biodegradation by bioaugmentation of dairy wastewater by fungal consortium on a bioreactor lab-scale and on a pilot-scale

A fungal consortium including Aspergillus niger, Mucor hiemalis and Galactomyces geotrichum was tested for the treatment of dairy wastewater. The bio-augmentation method was tested at lab-scale (4 L), at pilot scale (110 L) and at an industrial scale in Wastewater Treatment Plants (WWTP). The positive impact of fungal addition was confirmed when fungi was beforehand accelerated by pre-culture on whey (5 g/L lactose) or on the dairy effluent. Indeed, chemical oxygen demand (COD) removal yields increased from 55% to 75% for model medium, diluted milk. While after inoculation of an industrial biological tank from a dairy factory with the fungal consortium accelerated by pre-cultivation in a 1000 L pilot plant, the outlet COD values decreased from values above the standard one (100 mg/L) to values in the range of 50-70 mg/L. In addition, there was a clear impact of fungal addition on the ’hard’ or non-biodegradable COD owing to the significant reduction of the increase of the COD on BOD 5 ratio between the inlet and the outlet of the biological tank of WWTP. It was in the range of 451%-1111% before adding fungal consortium, and in the range of 257%-153% after bio-augmentation with fungi. An inoculated bioreactor with fungal consortium was developed at lab-scale and demonstrated successfully at pilot scale in WWTP.     

水中脲类除草剂Chlortoluron氯化产物鉴定、降解途径探究

对不同pH下Chlortoluron氯化后生成的非挥发性中间产物和挥发性产物进行了研究。对Chlortoluron氯化后的非挥发性中间产物的UPLC-ESI-MS鉴定发现了m/z为213、229、263、281、和247的离子,分析表明它们分别是Chlortoluron及其一羟基、一氯羟基、二氯和一氯衍生物。对Chlortoluron氯化后的挥发性产物采用吹扫补集-GC-MS进行分析鉴定发现了三氯甲烷(CF)、二氯硝基甲烷(DCNM)、二氯乙腈(DCAN)、1,1-2-二氯丙酮(1,1-DCP)、三氯硝基甲烷(TCNM)和1,1,1-2-三氯丙酮(1,1,1-TCP)六种消毒副产物。根据本研究中的实验结果分析和推测,在Chlortoluron的氯化过程中,苯环上和脲基链上都经历了羟基化、氧化和取代反应,接着苯环被打破,随后生成了更为有害的副产物,基于此,本文推断了Chlortoluron的氯化降解途径。     

丛枝菌对转Bt基因棉根际土壤营养物质及酶活性的影响

转Bt基因抗虫棉已在全球范围内广泛种植,然而Bt棉根际分泌物是否会影响土壤理化性质及土壤功能尚缺乏深入研究。通过盆栽实验方法,设计不同的棉花品种与是否接种丛枝菌总共4个处理,以此研究Bt棉和接种丛枝菌根真菌对植物根际土壤营养物质含量以及土壤酶活性的影响。结果显示:丛枝菌可以使non-Bt棉和Bt棉根际土壤营养物质中的土壤有机质和土壤总氮含量显著增加,但是对根际土壤全磷却鲜有影响。转基因对于不同品种棉花根际土壤酶,丛枝菌均能有效增强其活性。由此表明,丛枝菌对Bt棉和non-Br棉根际土壤环境均具有改善作用。     

染料废水处理技术现状与发展

介绍了染料废水的物理、化学和生物处理技术,分析了其去除原理和工艺优缺点,提出了未来染料废水处理技术的发展走向——高效、经济、适应性强、清洁性的废水处理技术。     

金属矿山废弃地类型划分与生态退化特征

由于矿山开采中地表结构扰动、环境污染等因素导致矿山废弃地生态系统极度退化。通过对其产生原因和占地现状、特征的分析,将金属矿山废弃地划分为5大类15个类型,对其生态退化特征进行了评价;其中地表结构的不稳定性、土壤和植被的缺失及重金属离子污染是生态退化的主要限制性特征,也是生态恢复的难点和重点,并对不同类型金属矿山废弃地的生态治理措施进行了探讨。