Decrease In Cu Research Articles

Mechanism of ATPase-mediated Cu+ Export and Delivery to Periplasmic Chaperones: THE INTERACTION OF ESCHERICHIA COLI CopA AND CusF

Cellular copper homeostasis requires transmembrane transport and compartmental trafficking while maintaining the cell essentially free of uncomplexed Cu(2+/+). In bacteria, soluble cytoplasmic and periplasmic chaperones bind and deliver Cu(+) to target transporters or metalloenzymes. Transmembrane Cu(+)-ATPases couple the hydrolysis of ATP to the efflux of cytoplasmic Cu(+). Cytosolic Cu(+) chaperones (CopZ) interact with a structural platform in Cu(+)-ATPases (CopA) and deliver copper into the ion permeation path. CusF is a periplasmic Cu(+) chaperone that supplies Cu(+) to the CusCBA system for efflux to the extracellular milieu. In this report, using Escherichia coli CopA and CusF, direct Cu(+) transfer from the ATPase to the periplasmic chaperone was observed. This required the specific interaction of the Cu(+)-bound form of CopA with apo-CusF for subsequent metal transfer upon ATP hydrolysis. As expected, the reverse Cu(+) transfer from CusF to CopA was not observed. Mutation of CopA extracellular loops or the electropositive surface of CusF led to a decrease in Cu(+) transfer efficiency. On the other hand, mutation of Met and Glu residues proposed to be part of the metal exit site in the ATPase yielded enzymes with lower turnover rates, although Cu(+) transfer was minimally affected. These results show how soluble chaperones obtain Cu(+) from transmembrane transporters. Furthermore, by explaining the movement of Cu(+) from the cytoplasmic pool to the extracellular milieu, these data support a mechanism by which cytoplasmic Cu(+) can be precisely directed to periplasmic targets via specific transporter-chaperone interactions.

Speciation of Cu and Zn in soil solution in a long-term fertilization experiment

Abstract The changes of the concentration of Cu and Zn in the soil solution and the percentage of particular forms of these elements in the soil solution were investigated in the long-term fertilization experiment. The soil solution was obtained following the vacuum displacement method. Speciation of copper and zinc ions was determined with MINTEQA2 for Windows software. The results of the investigation indicated that exclusive mineral fertilization (NPK) caused an increase of Cu and Zn concentration in the soil solution. Organic fertilization (FYM) resulted in a decrease of Cu and an increase of Zn concentration in the soil solution. Liming limited mobility of both analysed elements. The results of speciation analysis showed that regardless of the fertilization mode, the organo-mineral complexes are the main form of Cu occurring in soil solution. The percentage of Cu-DOC complexes ranges from 76.5 to 85.2% of the total concentration of Cu in the soil solution. The particular forms of copper can be sorted depending on the percentage in the soil solution as follows: Cu-DOC>Cu2+>Cu-CO3. The main form of Zn in the soil solution are active Zn2+ ions. The share of Zn2+ in total zinc concentration in the soil solution ranged from 76.9% to 86.4%. Forms of zinc in the soil solution can be arranged with regard to their percentage as follows: Zn2+>Zn-DOC>ZnCl+>ZnHCO3+.

Long-term assessment of the environmental fate of heavy metals in agricultural soil after cessation of organic waste treatments

The current study examined the anthropogenic accumulation and natural decrease in metal concentrations in agricultural soils following organic waste application. Three common organic wastes, including municipal sewage sludge, alcohol fermentation processing sludge, and pig manure compost (PMC), were applied annually to an agricultural soil under field conditions over 7 years (1994-2000) at a rate of 12.5, 25, and 50 ton ha(-1) year(-1) and the soil accumulation of three metals of concern (Cu, Pb, and Zn) was monitored. Subsequently, organic waste amendments ceased and the experimental plots were managed using conventional fertilization for another 10 years (2001-2010) and the natural decrease in metal concentrations monitored. Although Cu and Zn concentrations in all experimental plots did not exceed the relevant guideline values (150 mg kg(-1) for Cu and 300 mg kg(-1) for Zn), significant increases in metal concentrations were observed from cumulative application of organic wastes over 7 years. For instance, PMC treatment resulted in an increase in Cu and Zn from 9.8 and 72 mg kg(-1) to 108.2 and 214.3 mg kg(-1), respectively. In addition, the natural decrease in Cu and Zn was not significant as soils amended with PMC showed only a 16 and 19 % decline in Cu and Zn concentrations, respectively, even 10 years after amendment ceased. This research suggested that more attention must be paid during production of organic waste-based amendments and at the application stage.

Pollutant removal from industrial discharge water using individual and combined effects of adsorption and ion-exchange processes: Chemical abatement

In this study, adsorption-oriented processes for pollutant removal from metal polycontaminated surface-finishing discharge water were applied individually as well as in combination with ion-exchange treatment to remove the remaining metal ions and organic load. Several materials were compared using batch experiments, namely an activated carbon, three ion-exchange resins (IRA 402Cl, IR 120H and TP 207), and two non-conventional cross-linked polysaccharide-based biosorbents (starch and cyclodextrin). This article presents the abatements obtained in chemical pollution as monitored by complete chemical analysis. For the same experimental conditions (similar discharge water, pollutant concentrations, stirring rate, contact time, and initial pH), the highest levels of pollutant removal were attained with the combined use of two materials, an activated carbon and a mixture of two ion-exchange resins. This physicochemical treatment effectively lowered the main pollutants present in the discharge water such as Cu, Ni and COD, by more than 96%, 79% and 74% respectively (average values for three samples), while the treatment with carbon alone lowered them by 58%, 9% and 70%, and resins alone by 85%, 61% and 16%. Similar interesting results were obtained with the cyclodextrin-based adsorbent and its use alone was sufficient to obtain decreases in Cu, Ni and COD of more than 94%, 77% and 67% respectively. The adsorption-oriented process using cyclodextrin polymer could be an advantageous approach for removing organic and metallic pollutants from metal surface-finishing discharge water due to the non-toxic character of CD to humans and the environment.

The influence of protein folding on the copper affinities of trafficking and target sites

The relative influence of protein unfolding on the Cu(I) affinity of trafficking and target sites for copper has been determined. For the copper metallochaperone Atx1 from Synechocystis PCC 6803 (a cyanobacterium), Saccharomyces cerevisiae and humans unfolding in urea results in a decrease in the Cu(I) affinity from (4-5) × 10(17) M(-1) to (1-3) × 10(16) M(-1) at pH 7. The affinities of the unfolded Atx1s are similar to those for CXXC-containing peptides. Partial unfolding, due to the loop 5 His61Lys mutation in Synechocystis Atx1, gives rise to a more limited decrease in Cu(I) affinity. For the copper target protein plastocyanin from Synechocystis, chemical unfolding results in the Cu(I) affinity decreasing by 5-orders of magnitude. This differential influence of protein unfolding on Cu(I) affinity is due to a more complex copper site structure in the target protein, including numerous interactions of non-coordinating residues with ligating amino acids. This second-coordination sphere is much simpler in the Atx1s with the main interaction provided by the loop 5 residue that tunes the Cu(I) affinity by altering the pK(a) of the C-terminal Cys ligand of the CXXC motif. This interaction and others are absent in the unfolded Atx1s and the two Cys ligands have pK(a) values reminiscent of free thiols (>8) resulting in lowered Cu(I) affinities at pH 7. Residues close to the active site of the thiol-disulfide oxidoreductase thioredoxin appear to lower the Cu(I) affinity of its CXXC motif to 3.1 × 10(15) M(-1) at pH 7, presumably to prevent copper binding in vivo. The structure of a copper site, including the number and relative position of ligands in the primary structure and the complexity of the second-coordination sphere, results in dramatically different effects of unfolding on Cu(I) affinity that has important implications for copper homeostasis.

Protective effect of maifanite against cadmium-induced oxidative stress to rats hippocampus by regulating the balance and metabolism of metals

In this paper, the author reported the effect of maifanite on the learning and memory of rats suffering Cd poisoning by step-down and step-through test, analyzed the content of MDA, MT, SOD, and GSH-Px in the hippocampus of rats respectively, and assayed the content of Fe, Cu, Zn, Mn, Se, and Cd in the hippocampus of rats. In the step-down test, it is found that maifanite can reduce the number of electric shock, prolong step-down latency, and cut down error times when rats are exposed to Cd 24 h. In the step-through test, maifanite can obviously prolong the latency of entering the dark cabin of rats suffering Cd poisoning. The exogenous Cd can lead to the decrease of SOD and GSH-Px activity and the increase of MDA and MT content. The alternation of maifanite and Cd by the gavage can significantly increase the SOD and GSH-Px activity as well as MT content, while lessening the MDA content. The accumulation of exogenous Cd in hippocampus causes the increase of Zn, Fe, Mn, and Cd content, and the decrease of Cu and Se content. The intake of maifanite can regulate the imbalance of metals content and make its content near to the of level control group. The research shows that maifanite can improve the ability of learning and memory of rats suffering Cd poisoning, increase MT formation and lower hyperoxidative damage. Maifanite has the function of balancing the content of trace elements in rats suffering Cd poisoning, and meanwhile can alleviate the toxicity of Cd effectively.

Decreased copper in Alzheimer's disease brain is predominantly in the soluble extractable fraction.

Alzheimer's disease (AD) is the leading cause of dementia and represents a significant burden on the global economy and society. The role of transition metals, in particular copper (Cu), in AD has become of significant interest due to the dyshomeostasis of these essential elements, which can impart profound effects on cell viability and neuronal function. We tested the hypothesis that there is a systemic perturbation in Cu compartmentalization in AD, within the brain as well as in the periphery, specifically within erythrocytes. Our results showed that the previously reported decrease in Cu within the human frontal cortex was confined to the soluble (P < 0.05) and total homogenate (P < 0.05) fractions. No differences were observed in Cu concentration in erythrocytes. Our data indicate that there is a brain specific alteration in Cu levels in AD localized to the soluble extracted material, which is not reflected in erythrocytes. Further studies using metalloproteomics approaches will be able to elucidate the metabolic mechanism(s) that results in the decreased brain Cu levels during the progression of AD.

Structural Study of Cu-Deficient Cu2(1-x)ZnSnSe4Solar Cell Materials by X-ray Diffraction and X-ray Absorption Fine Structure

Cu-poor Cu2(1-x)ZnSnSe4 powders were prepared from elemental powders. The crystal structure of Cu-poor Cu2(1-x)ZnSnSe4 was examined by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) analyses. Kesterite-type Cu2(1-x)ZnSnSe4 could be prepared in the range of 0≤x ≤0.0750. The lattice parameters were refined by the Rietveld analysis of X-ray diffraction data. The lattice constants a and c decreased with a decrease in the Cu/(Zn+Sn) ratio. However, there was little change in c/a value. On the other hand, the position of the Se atom (u parameters) changed considerably. The XAFS study showed that the local structure of Sn in Cu2ZnSnSe4 (CZTSe) changed with a decrease in Cu/(Zn+Sn) ratio and the local structural changes in Cu, Zn, or Se could not be clearly observed. These local structural changes around Sn are due to the disordering of Cu, Zn, and Sn atoms. The diffuse reflectance spectra showed that the band gap of Cu2ZnSnSe4 is 0.98 eV and that the band gaps do not depend on Cu/(Zn+Sn) ratio in the range of 0≤x ≤0.0750.

Structural Study of Cu-Deficient Cu2(1-x)ZnSnSe4 Solar Cell Materials by X-ray Diffraction and X-ray Absorption Fine Structure

Cu-poor Cu2(1-x)ZnSnSe4 powders were prepared from elemental powders. The crystal structure of Cu-poor Cu2(1-x)ZnSnSe4 was examined by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) analyses. Kesterite-type Cu2(1-x)ZnSnSe4 could be prepared in the range of 0≤x ≤0.0750. The lattice parameters were refined by the Rietveld analysis of X-ray diffraction data. The lattice constants a and c decreased with a decrease in the Cu/(Zn+Sn) ratio. However, there was little change in c/a value. On the other hand, the position of the Se atom (u parameters) changed considerably. The XAFS study showed that the local structure of Sn in Cu2ZnSnSe4 (CZTSe) changed with a decrease in Cu/(Zn+Sn) ratio and the local structural changes in Cu, Zn, or Se could not be clearly observed. These local structural changes around Sn are due to the disordering of Cu, Zn, and Sn atoms. The diffuse reflectance spectra showed that the band gap of Cu2ZnSnSe4 is 0.98 eV and that the band gaps do not depend on Cu/(Zn+Sn) ratio in the range of 0≤x ≤0.0750.

Cd, Cu, Zn, Se, and Metallothioneins in Two Amphibians, Necturus maculosus (Amphibia, Caudata) and Bufo bufo (Amphibia, Anura)

The accumulation of cadmium, its affinity for metallothioneins (MTs), and its relation to copper, zinc, and selenium were investigated in the experimental mudpuppy Necturus maculosus and the common toad Bufo bufo captured in nature. Specimens of N. maculosus were exposed to waterborne Cd (85μg/L) for up to 40days. Exposure resulted in tissue-dependent accumulation of Cd in the order kidney, gills > intestine, liver, brain > pancreas, skin, spleen, and gonads. During the 40-day exposure, concentrations increased close to 1μg/g in kidneys and gills (0.64-0.95 and 0.52-0.76; n = 4), whereas the levels stayed below 0.5 in liver (0.14-0.29; n = 4) and other organs. Cd exposure was accompanied by an increase of Zn and Cu in kidneys and Zn in skin, while a decrease of Cu was observed in muscles and skin. Cytosol metallothioneins (MTs) were detected as Cu,Zn-thioneins in liver and Zn,Cu-thioneins in gills and kidney, with the presence of Se in all cases. After exposure, Cd binding to MTs was clearly observed in cytosol of gills as Zn,Cu,Cd-thionein and in pellet extract of kidneys as Zn,Cu,Cd-thioneins. The results indicate low Cd storage in liver with almost undetectable Cd in liver MT fractions. In field trapped Bufo bufo (spring and autumn animals), Cd levels were followed in four organs and found to be in the order kidney > liver (0.56-5.0μg/g >0.03-0.72μg/g; n = 11, spring and autumn animals), with no detectable Cd in muscle and skin. At the tissue level, high positive correlations between Cd, Cu, and Se were found in liver (all r > 0.80; α = 0.05, n = 5), and between Cd and Se in kidney (r = 0.76; n = 5) of autumn animals, possibly connected with the storage of excess elements in biologically inert forms. In the liver of spring animals, having higher tissue level of Cd than autumn ones, part of the Cd was identified as Cu,Zn,Cd-thioneins with traces of Se. As both species are special in having liver Cu levels higher than Zn, the observed highly preferential Cd load in kidney seems reasonable. The relatively low Cd found in liver can be attributed to its excretion through bile and its inability to displace Cu from MTs. The associations of selenium observed with Cd and/or Cu (on the tissue and cell level) point to selenium involvement in the detoxification of excessive cadmium and copper through immobilization.

Chalcophile element systematics in volcanic glasses from the northwestern Lau Basin

The Lau Backarc Basin (S.W. Pacific) hosts numerous spreading centers and rifts, including the Rochambeau Rifts (RR), Northwest Lau Spreading Center (NWLSC), and Central Lau Spreading Center (CLSC). Samples from the NWLSC, RR and CLSC show no evidence for a subduction‐derived component in their mantle source regions or evidence for S loss during eruption. The contents of S in glasses from the NWLSC and many from the CLSC and the RR are lower than MORB at a given FeOTOT, indicating melts were initially sulfide‐undersaturated. During differentiation, the decrease in Cu and Ag contents at ∼7 wt% MgO and the concomitant change in chalcophile element ratios marks the onset of sulfide saturation. The initially sulfide‐undersaturated compositions of samples from the NWLSC are attributed to partial melting at pressures higher than parental MORB. The NWLSC and some of the CLSC and RR samples are strikingly enriched in Cu and Ag compared with MORB. This is a characteristic shared by basalts generated in many plume‐related tectonic settings. The only plume‐related samples that appear to be sulfide‐saturated during differentiation and plot within the MORB array are alkaline basalts from the nearby Samoan islands. RR and CLSC basalts have a range in Cu contents, which can be explained by variable mixing between a high‐Cu NWLSC‐type melt with low‐Cu sources from the Samoan plume (RR) and MORB‐type mantle (CLSC). The RR alone of these three suites have markedly positive Pb, As, Tl and subtle Mo anomalies, possibly related to assimilation of old, hydrothermally altered, Vitiaz Arc crust.

Quantitative Determination of Click Reaction in the Presence of Glycine Derivatives and in Dilute Solution

The click reaction is one of the latest techniques for the functional analysis of bioactive compounds and the analysis makes novel concepts and strategies for medicinal chemistry. N-methylated glycine derivatives have inhibitory activity for the click reaction in direct Cu(I) system because of decrease of Cu(I) concentration. The Cu(I) concentration recovered effectively by sodium ascorbate. Quantitative determination of click reaction at various ligand concentrations revealed that the decrease in reaction yields was observed in a substrate concentration-dependent manner.

Bio-imaging of metals in a mouse model of Alzheimer's disease by laser ablation inductively coupled plasma mass spectrometry

Quantitative mass spectrometry imaging (MSI) of metals in biological tissue sections by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) using matrix-matched laboratory standards has been established previously. Here an improved calibration strategy is proposed, correcting for variable section thickness by normalization of sample and standard ion intensities to the average 13 C + ion signal of all ablated sample and standard material, respectively. Altered metal metabolism is known in Alzheimer's disease of which amyloid precursor protein (APP) transgenic mice are a popular model. Quantitative distribution analysis of Fe, Zn, Cu and Mn in horizontal brain sections of 45 week old Tg2576 transgenic mice showed a 22% decrease of Cu and changes of Fe, Zn and Mn of −1%, −7% and −17%. Local evaluation across a set of anatomically defined regions of interest showed an increased circum-ventricular to parenchyma ratio of Cu pointing to a higher Cu efflux and a heterogeneous pattern of Fe changes pointing to clearance of Fe at the sites of early pathology. Congruencies to synchrotron X-ray fluorescence data on distinct types of APP mice are discussed. MSI by LA-ICP-MS thus proved as a valuable and versatile tool for studying the cerebral metallo-architecture and the validation of animal models.

Nickel Accumulation in Rape Shoots (Brassica napus L.) Increased by Putrescine

Application of exogenous putrescine (Put) increases nickel accumulation in rape shoots (Brassica napus), improving potential for phytoremediation of contaminated soils. Plants were grown within a growth chamber in water culture for five weeks, then 250–500 μM NiCl2 was added to rooting media. Within 5 days of treatment, damaging effects of nickel manifested as a reduction of root system size and a decrease of Cu and especially Fe content in young leaves. Spraying leaves of adult plants with Put markedly reduced toxic effects of Ni on root growth, enhanced leaf supply with Fe, and increased Ni content in young leaves by 2.5 times. Plant growth in medium with elevated levels of Ni stimulated accumulation of endogenous spermidine (Spd), spermine (Spm), and especially Put (by 4 times as compared with the control). Results suggest that Ni-induced accumulation of endogenous polyamines in rape leaves is caused by activation of long-distance metal transport within the plant and reduction of its toxicity due to Put chelating action.

Decrease of Cu and Fe concentrations from broiler droppings using dietary organometallic compounds

The purpose of this study was to determine the effect of the partial or total replacement of the inorganic Cu and Fe salts by organic forms of these elements on broiler performance and on the elimination of minerals through broiler droppings. A study was conducted for 42 days on 240 broiler chicks treated with trace elements chelates with amino acids: B-TRAXIMRTEC Cu-I30; BTRAXIMRTEC Fe-120. The broiler chicks were housed in cages (10 chicks per cage, 6 cages per group) and assigned to 4 groups (C, E1, E3 and E3) fed on the same corn-soybean meal-based diet. Phased-feeding was used according to the developmental stages of the broilers (starter, grower and finisher). Feed intake and the amount of droppings were recorded daily. The daily records of droppings and their chemical analysis was used to determine the trace elements load of the droppings. The total or partial replacement of the inorganic Cu and Fe salts by chelates of these minerals with amino acids in broiler diets didn?t affect broiler performance. The inclusion of Cu chelates in broiler diets at the level recommended by the manufacturer of by NRC decreased by at least 34% the level of Cu (environmentally toxic element) in the droppings. The corresponding decrease was of 5-21% for Fe.

Influence of annealing conditions on the structure and compositions of electrodeposited CuInSe 2 films

The synthesis of highly crystalline CuInSe 2 films through one-step electrodeposited CuInSe 2 precursors followed by annealing under selenium vapor is a promising approach for fabricating low cost, high efficiency solar cells. In this study, the phase structure and crystallinity of annealed samples prepared by electrodeposition were investigated using X-ray diffraction, Raman spectroscopy and scanning electron microscopy. A detailed Raman scattering analysis showed that the formation of the Cu–Se compound and crystalline quality of the CuInSe 2 can be controlled through varying the annealing temperature and annealing profile. Both the enhancement of the annealing temperature and the increase of the heating rate can lead to a significant decrease in Cu–Se compound and a remarkable increase in the grain size of the CuInSe 2.

Biosorption of copper(II) from aqueous solutions by Pleurotus cornucopiae

Pleurotus cornucopiae was used as biosorbent for the adsorption of Cu(II) ions in water. The adsorption process was carried out in a batch process and the effects of contact time, initial pH, initial Cu(II) ion concentration, adsorbent amount on the adsorption were investigated. The removal percentage of Cu(II) was increased with an increase in pH, biomass concentration and a decrease in Cu(II). Pleurotus cornucopiae exhibited the highest Cu(II) uptake of 25.25 mg · g−1 of biomass at pH 5 in the presence of 100 mg l−1 Cu(II) at 298°K. The experimental isotherm data were analysed using the Langmuir, Freundlich and Temkin equations. It was observed that Langmuir model exhibited the best fit to experimental data. The experimental data were analysed using four sorption kinetic models the pseudo first and second order equations, and the Elovich and the Intraparticle diffusion equation to determine the best fit equation for the biosorption of Cu(II) ions onto Pleurotus cornicopiae. Pseudo second order model des...

Effect of 1-1 electrolyte concentration on the adsorption/desorption of copper ion on synthetic birnessite

Purpose Oxides are ubiquitous in nature and play an important role in scavenging metal ions from soils and sediments. At the common pH range of the natural environment the well-studied Fe and Al oxides mostly carry a positive charge and adsorbed amounts of heavy metals, and their desorption percentages decrease with increasing ionic strength. The less well studied but also important Mn oxides possess negative charges in the natural environment and this will lead to a different behavior. Therefore, it is useful to further investigate how the electrolyte concentration and type affect the metal ion adsorption/desorption by Mn oxides. Materials and methods The phyllomanganate birnessite was synthesized with hydrochloric acid and potassium permanganate, and characterized by X-ray diffraction and transmission electron microscopy. The point of zero charge and specific surface area (SSA) were determined by, respectively, the rapid potentiometric titration method and BET-N2 method. The adsorption was measured after shaking the samples in contact with Cu(NO3)2 solution for 2 h and further equilibration for 22 h at pH 4.5 and 25± 1°C. The 1-1 electrolyte concentrations were adjusted to 0, 0.001, 0.01, 0.1, 0.5, and 1 mol L −1 KNO3 or KCl. Results and discussion The PZC and SSA of synthetic birnessite were 2.5 and 75 m 2 g −1 , respectively. The birnessite consisted of small needle-like particles. A maximum amount of Cu 2+ adsorbed on birnessite of 208±8 mmol kg −1 and 2.77±0.11 µmol m −2 by using the BET area is obtained. The adsorption amount decreased gradually with increasing ionic strength. This is primarily due to screening of the electrostatic attraction. For the same reason the percentage of desorption of Cu 2+ previously adsorbed on birnessite increased with increasing electrolyte concentration. Furthermore, the decrease of Cu 2+ adsorption with increasing ionic strength was higher in KCl solution than in KNO 3 solution. This difference is most likely related to Cu 2+ –Cl − complexation.

Adsorption and desorption of Cu(II) and Cd(II) in the tropical soils during pedogenesis in the basalt from Hainan, China

Adsorption and desorption of Cu(II) and Cd(II) in the soils derived from basalts aged 10, 1,330, and 2,290 kiloyears (ky) in the tropical regions of Hainan, China were investigated. X-ray diffraction analysis indicated that the clay minerals were dominated by smectite, halloysite, and kaolinite mixed with montmorillonite in the soil derived from 10 ky-basalt and by kaolinite, halloysite, and gibbsite in the soils derived from 1,330 and 2,290 ky-basalt. Soil cation exchange capacity (CEC) decreased with the increase in basalt age, while the content of soil-free iron oxides decreased for such increase in basalt age. The amount of Cu(II) and Cd(II) adsorbed by the soil derived from 10 ky-basalt was much higher than that adsorbed by the other two soils. A similar trend was observed for the desorption of Cu(II) and Cd(II) pre-adsorbed to these soils in 1 M KNO3. The desorption rate of Cu(II) decreased with the increase in age of basalts. This indicated that the electrostatic adsorption of Cu(II) decreased with the increase in degree of soil development. Similarly, the specific adsorption of Cu(II) increased with increase in degree of soil development. The desorption rate of Cd(II) showed much higher than the Cu(II), which ranged from 87.5% to 92.6%. This indicated that Cd(II) was adsorbed mainly through the electrostatic attraction. Removal of soil organic matter leads to the decrease in Cu(II) adsorption and the increase in Cu(II) desorption. The overall effect of organic matter removal on the adsorption and desorption of Cd(II) and desorption rate of Cd(II) was smaller compared to Cu(II).

Nutrient and anti-nutrient potentials of brown pigeon pea (Cajanus cajan var bicolor) seed flours.

Brown pigeon pea (Cajanus cajan var bicolor ) seeds purchased from Nsukka main market were processed into flours. The samples were sprouted, boiled or roasted. A cleaned, washed and dried sample served as control. Sprouting was done for 48h, boiling for 20 min androasting at 200 C for 5min. The boiled and sprouted samples were dehulled manually by rubbing in between palms. The roasted and control samples were dehulled using disc mill. All the samples were milled into flour using a hammer mill with 70mm mesh screen. Standardassay methods were used for sample analysis. Sprouting increased crude protein level of the control (19.74%) to 28.42% (P.0.05). All treatments significantly decreased crude fat level from 2.19 to1.76% in the boiled sample. Crude fiber level of the control (5.29%) decreasedafter processing to 3.04, 4.11 and 3.27% in the sprouted, boiled and roasted samples, respectively. Sprouting decreased Ca level. All the treatments led to decreases in Cu, Zn, and pro-vitamin A levels. Mg level of the control (137.91mg/100g) increased significantly to 148.63mg /100g in the sprouted sample (P.0.05). Sprouting androasting were more effective in decreasing tannin and trypsin inhibitor levels, respectively.