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1.
该研究以地衣体内分离培养的3种共生藻体(A、B、C)为材料,采用光学显微镜徒手切片技术,测定地衣体内藻细胞存活率;并采用BCO和双硫腙、二甲酚橙和碘化钾-罗丹明B分光光度法,测定培养液和藻体内不同重金属含量,分析3种共生藻体对重金属Cu^2+、Zn^2+、Pb^2+、Cd^2+的吸附特性及其耐受性差异,以明确地衣与重金属胁迫的关系,为重金属污染水体的生物修复提供理论依据。结果显示:(1)在不同重金属胁迫下,3种藻体对4种重金属的耐性大小均表现为Zn^2+>Pb^2+>Cu^2+>Cd^2+,重金属对3种藻体的毒性大小依次是Cu^2+(藻体B>藻体A>藻体C)、Zn^2+(藻体B>藻体A>藻体C)、Pb^2+(藻体B>藻体A>藻体C)、Cd2+(藻体B>藻体C>藻体A)。(2)3种藻体对Zn^2+、Pb^2+的吸附性均高于Cu2+和Cd2+,而且藻体B对不同重金属的吸附性能均高于藻体A和C。(3)3种藻体所吸附的重金属含量与其胁迫浓度及培养时间均呈极显著正相关关系(P<0.01),3种藻体对重金属的耐受性与吸附性呈正相关关系。研究发现,来自地衣体的3种藻体对Cu^2+、Zn^2+、Pb^2+和Cd^2+的耐受性和吸附性远远高于一些自由生长藻类,证明来自地衣体的藻类是修复重金属污染生物吸附剂的良好材料,该研究结果为地衣体内藻在水体重金属污染生物修复中的实际应用提供了理论依据。  相似文献   

2.
以拟南芥原生质体为实验体系,研究不同浓度的3种重金属离子对拟南芥原生质体的毒性和DNA损伤的差异。结果表明,用1-5mmol·L^-1的Zn^2+、Cd^2+和Cu^2+分别处理的拟南芥原生质体,2小时内活力逐渐下降,并表现出明显的浓度依赖性:与相同浓度的Cd^2+和Cu^2+相比,Zn^2+对拟南芥原生质体活力的影响程度较小,表现出较低的毒性。单细胞凝胶电泳检测发现,用0.1-0.8mmol·L^-1的Zn^2+、Cd^2+和Cu^2+分别处理拟南芥原生质体30分钟,以OTM值表示的原生质体DNA损伤量随重金属离子浓度的增加而递增:相同浓度(0.5mmol·L^-1)的3种重金属离子相比,Zn^2+对原生质体的遗传毒性明显低于Cu^2+和Cd^2+。综合原生质体活力和DNA损伤的单细胞凝胶电泳检测结果,发现ZnO^2+对拟南芥原生质体的遗传毒性较低,而CdO^2+和Cu^2+的遗传毒性较高。本研究建立的拟南芥原生质体实验体系,结合运用单细胞凝胶电泳技术,能够快速、灵敏地检测重金属对植物细胞的遗传毒性。  相似文献   

3.
小球藻生物富集锌、镉机制的研究   总被引:2,自引:0,他引:2  
林芃  刘艳  杨海波 《生物技术》2002,12(5):17-18
藻类对许多重金属具有较强的生物富集能力,小球藻(Chlorella spp.)分别在不同系列Zn^2 ,Cd^2 浓度下培养8d间隔2d,测定小球藻的生物量及Zn和Cd的含量。结果表明,小球藻随水体中Zn^2 和Cd^2 的浓度不同,在重重金属水体中暴露时间不同,具有不同的富集速率和能力。  相似文献   

4.
为了探讨同一菌根真菌不同菌株对重金属的耐受性,选用采集于内蒙古阴山山脉不同地区的粘盖牛肝菌(Suillus bovinus)的不同菌株进行研究。首先,在不同浓度Zn^2 、Cd^2 液体培养基中培养菌丝体,以了解各菌株菌丝体对重金属的耐受性及吸附能力,采用烘干法和原予吸收法分别测定菌丝体的生物量和菌丝体、培养液中Zn^2 、Cd^2 含量,结果表明:劈柴沟粘盖牛肝菌在Zn^2 、Cd^2 胁迫条件下,生物量、吸附能力约为其余各菌株的1.5~2倍。其次,为了探明油松(Pinus tabulaeformis)形成菌根后对Zn^2 、Cd^2 胁迫的耐受性及其耐受机理,采用一次性定量浇灌不同浓度Zn^2 、Cd^2 溶液的方法,测定了菌根化油松苗地上、地下生物量及Zn^2 、Cd^2 含量的分配,结果表明:菌根形成后能显著促进油松的生长及对Zn^2 、Cd^2 胁迫的耐受性,并且菌根能够帮助油松吸收基质中大量的Zn^2 、Cd^2 ,根中重金属的含量是茎叶中的2~3倍以上,非菌根苗在重金属浓度稍高(Zn^2 400mg/kg;Cd^2 40mg/kg)时就会死亡。经方差分析及多重比较证实,劈柴沟粘盖牛肝菌对Zn^2 、Cd^2 的耐受性及对油松的促生效果与其它各菌株存在显著的差异,这可能是它通过把吸收的Zn^2 、Cd^2 最大限度地输送到根中的同时,也输送到了茎叶中,使重金属在体内得到一定程度的稀释,使自身免受毒害。  相似文献   

5.
利用水培试验研究了在不同营养环境条件下几种二价金属营养元素与镉的互作关系及其水稻吸收运转镉的影响。研究结果表明,培养液中全部营养元素供应水平变化,二价金属元素浓度变化均对水稻吸收镉产生显著影响。Cd浓度保持为2μmol/L不变,随着全部必须元素浓度系数从0. 25提高到2. 0,水稻根系和茎叶Cd含量分别降低42. 5%和64. 5%。在没有其它二价阳离子干扰的情况下,Mg^(2+)、Fe^(2+)、Zn^(2+)、Mn^(2+)、Cu^(2+)均强烈抑制水稻对镉的吸收,水稻根系镉含量降低至对照的15. 4%~61. 6%,茎叶镉含量降低至对照的20. 2%~87. 5%。在木村B培养液中增量供应Zn^(2+)或Mn^(2+)均大幅度促进镉在根系、茎叶和稻谷积累,其中增量供应Zn^(2+)处理的水稻根、茎叶和稻谷镉含量分别比对照增加45. 5%、177. 4%、250. 8%,而增量供应Mn^(2+)处理的水稻根系、茎叶、稻谷镉含量分别比对照增加20. 2%、117. 4%、227. 1%。在所有二价金属元素中,Cu^(2+)对水稻吸收Cd^(2+)的拮抗作用最强,而且铜-镉拮抗关系受营养环境的影响较小。培养液中增量供应Cu^(2+)导致水稻吸收镉大幅减少,根系、茎叶、稻谷镉含量分别比对照降低51. 4%、45. 2%、52. 2%;培养液缺Cu^(2+)则导致根系和茎叶镉含量分别比对照增加177%和114%。研究结果表明,在镉污染稻田适度施用铜肥、控制锌锰的输入、在水稻生长发育期保持较高土壤营养水平可能是控制水稻积累镉的营养调控方法。  相似文献   

6.
胞外弹性蛋白酶产生菌的筛选及酶的纯化   总被引:7,自引:0,他引:7  
从土壤中筛选到132株能分泌胞外弹性蛋白酶的细菌,经复筛得5株产酶在100u/ml以上,其中No.17-87菌每毫升发酵液含酶120单位,经鉴定为芳香黄杆菌。该菌在26℃发酵21小时酶产量即达峰值。从发酵液中分离纯化得到聚丙烯酰胺凝胶电泳均一的酶制品。SDS-PAGE测得分子量为21300,最适作用温度为50℃,最适作用pH为7.4,在pH4.5—9.5范围内稳定,重金属离子Fe^(3+)、Zn^(2+)、Cu^(2+)、Cr^(3+)、CO^(2+)、Ni^(2+)、Hg^(2+)和Ag^+等严重抑制酶活性。  相似文献   

7.
镉(cadmium,Cd)是环境中常见的一种重金属,Cd^(2+)可以通过穿透血脑屏障,产生神经毒性,从而诱发各种神经退行性疾病,雷公藤红素是雷公藤的一种有效成分,具有抗癌、抗炎等一系列药理作用,本文探究雷公藤红素对Cd^(2+)诱导的相应神经毒性的影响作用。通过细胞增殖实验、细胞膜完整性实验、细胞形态实验探索了Cd^(2+)对小胶质细胞HMC3活力的影响;通过一氧化氮(NO)检测实验、脂质过氧化(malondialdehyde,MDA)检测实验、蛋白免疫印迹实验分析了Cd^(2+)的神经毒性以及雷公藤红素对Cd^(2+)诱导的相应神经毒性的影响。结果表明:与对照组相比,当Cd^(2+)浓度达到40μmol/L时,对HMC3细胞增殖抑制率为(57.17±8.23)%(P<0.01,n=5),继续增大Cd^(2+)浓度,细胞活性将进一步降低;当Cd^(2+)浓度达到40μmol/L以上时,HMC3的细胞膜明显受到破坏,并且破坏作用与浓度呈剂量依赖性关系;随着Cd^(2+)浓度的增加,细胞形态开始变化,贴壁效果变差。Cd^(2+)使HMC3细胞释放的NO量显著增加,而雷公藤红素能够有效地抑制Cd^(2+)诱导的HMC3细胞NO的释放;Cd^(2+)使HMC3细胞脂质过氧化水平显著增加,加入10^(-7) mol/L雷公藤红素后,MDA的释放量显著减少;Cd^(2+)会使p-PI3K蛋白含量增加,而加入了雷公藤红素(10^(-7)、10^(-6) mol/L)后,p-PI3K蛋白和p-AKT蛋白的激活均被抑制,从而抑制了细胞凋亡。综上所述,雷公藤红素能够抑制Cd^(2+)诱导的小胶质细胞毒性,从而起到神经保护作用。  相似文献   

8.
采用饲料含毒法,测定了棕尾别麻蝇Boettcherisca peregrine 1日龄幼虫连续取食含不同浓度Cd^2+或Cu^2+的人工饲料,体内丙二醛含量的变化过程。实验结果表明:二种重金属离子能诱导昆虫的脂质过氧化反应,并且存在浓度依赖效应和时间依赖效应。在0—1600μg/g饲料浓度范围内,丙二醛(malondialdehyde,MDA)含量与幼虫取食Cd^2+和Cu^2+的浓度呈线性关系,所求回归方程分别为y=0.2789+0.0002x和y=0.3141+0.0002x。当处理浓度为800μg/g时,在0-120h时间内,MDA含量与幼虫取食Cd^2+和Cu^2+的时间呈线性关系,回归方程分别为y=0.3041+0.0042x和y=0.3251+0.0029x。  相似文献   

9.
转基因衣藻对重金属的抗性及对镉离子的富集   总被引:1,自引:0,他引:1  
邓旭  魏斌  胡章立 《生物技术》2007,17(6):66-68
目的:研究了转基因衣藻对不同重金属离子的抗性和对Cd^2+的富集行为。方法:将MT-like基因在莱茵衣藻细胞中的表达后通过摇瓶实验测试其对重金属离子的抗性和富集能力。结果:转基因衣藻对Pb^2+、Zn^2+和Cd^2+三种重金属离子的抗性得到明显增强,其中以对Zn^2+的抗性增强最为显著。转基因藻对Cd^2+的富集能力经MT-like蛋白表达后较野生藻细胞有较大增加,最大达到144.48μmol/g,为野生藻的8.3倍。结论:转基因衣藻对重金属离子的抗性和对Cd^2+的富集能力较野生衣藻有较大提高。  相似文献   

10.
[目的]利用球孢白僵菌进行固定化生物转化,将底物R-(+)-2-苯氧基丙酸(D-PPA)转化合成产物R-(+)-2-(4-羟基苯氧基)丙酸(D-HPPA)。[方法]利用海藻酸钠和聚乙烯醇对球孢白僵菌进行包埋处理,并对包埋条件进行累积优化。[结果]4%海藻酸钠和4. 5%聚乙烯醇混合后,再加入2. 5%的氯化钙作为交联剂交联8 h。在此包埋条件下制备的白僵菌凝胶珠,置于30 g/L的D-PPA进行固定化生物转化。反应5 d后,产物浓度最终为29. 9 g/L,平均生产强度为5. 98 g/(L·d),底物转化率为99. 7%。[结论]海藻酸钠和聚乙烯醇可用于白僵菌的固定化,且较游离菌体的生物转化的反应周期缩短28. 6%,平均生产强度增加64. 7%,底物转化率提高17. 7%。  相似文献   

11.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

12.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

13.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

14.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

15.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

16.
17.
Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.  相似文献   

18.
We report 19 new species records for the faunal list of Coleoptera in New Brunswick, Canada, six of which are new records for the Maritime provinces, and one of which is new Canadian record. We also provide the first recent records for five additional species in New Brunswick. One new species of Stenotrachelidae, Cephaloon ungulare LeConte, is added to the New Brunswick faunal list. Additional records are provided for Cephaloon lepturides Newman, as well the first recent record of Nematoplus collaris LeConte. Two species of Oedemeridae, Asclera puncticollis (Say) and Asclera ruficollis (Say), are newly reported for New Brunswick, and additional locality and bionomic data are provided for Calopus angustus LeConte and Ditylus caeruleus (Randall). The records of Ditylus caerulus are the first recent records for the province. Three species of Meloidae, Epicauta pestifera Werner, Lytta sayi LeConte, and Meloe augustcollis Say are reported the first time for New Brunswick; Epicauta pestifera is newly recorded in Canada. Lacconotus punctatus LeConte and the family Mycteridaeis newly recorded for New Brunswick. The first recent records of Borus unicolor Say (Boridae) are reported from the province. One new species of Pythidae, Pytho siedlitzi Blair, and the first recent records of Pytho niger Kirby are added to the faunal list of New Brunswick. Three species of Pyrochroidae are newly reported for the province, including Pedilus canaliculatus (LeConte) and Pedilus elegans (Hentz), which are new for the Maritime provinces. Five species of Anthicidae and the first recent record of Anthicus cervinus LaFerté-Sénectére are newly reported for New Brunswick. Anthicus melancholicus LaFerté-Sénectère, Sapintus pubescens (LaFerté-Sénectère), Notoxus bifasciatus (LeConte), and Stereopalpus rufipes Casey are new to the Maritime provinces faunal list. Ambyderus granularis (LeConte) is removed from the faunal list of the province. Three species of Aderidae, Vanonus huronicus Casey, Zonantes fasciatus (Melsheimer), and Zonantes pallidusWerner, are newly recorded for New Brunswick; Zonantes fasciatus and Vanonus huronicus are new for the Maritime provinces' faunal list. Collection data, bionomic data, and distribution maps are presented for all these species.  相似文献   

19.
We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.  相似文献   

20.
Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera. The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents and shown to be controlled by three alleles,C 12,C 25, andC . A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled by six codominant alleles (G 10.19.20,G 10.19,G 10.20,G 10,G 19,G 20) and a recessive allele (G ). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively. This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, New South Wales 2031, Australia.  相似文献   

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