共查询到20条相似文献,搜索用时 31 毫秒
1.
Katarzyna Chojnacka 《World journal of microbiology & biotechnology》2007,23(8):1139-1147
The paper discusses biosorption of Cr(III), Cu(II), Mn(II), Zn(II) and Co(II) to the biomass of Chlorella vulgaris, to produce a biologically bound, concentrated form of microelements. The kinetics of biosorption was described with a pseudo-second
order equation and equilibrium with the Langmuir isotherm. The mechanism of biosorption was identified as cation-exchange
with alkaline metals. Cation-exchange capacity was evaluated as 4.07 meq g−1. The effect of operation conditions, pH and temperature, on biosorption performance was investigated and the best operation
conditions for biosorption were selected (pH 5, temperature 25 °C). The maximum sorption capacity of microelements was determined
in single-metal system at pH 5 and 25 °C: Zn(II) 3.30 meq g−1, Cu(II) 1.77 meq g−1, Co(II) 1.75 meq g−1, Cr(III) 1.74 meq g−1, Mn(II) 0.764 meq g−1. Biosorption experiments were also carried out in multi-metal system. The biomass of C. vulgaris enriched with microelements via the process of biosorption in both single- and multi-metal system was discussed in terms
of preparation of feed supplement for laying hens and piglets. The experiments showed that 1 kg of conventional feed for laying
hens can be supplemented with 0.20 g of the biomass enriched with microelements and for piglets with 0.15 g of the preparation. 相似文献
2.
José Antonio Morillo Pérez Rafael García-Ribera Teresa Quesada Margarita Aguilera Alberto Ramos-Cormenzana Mercedes Monteoliva-Sánchez 《World journal of microbiology & biotechnology》2008,24(11):2699-2704
The biosorption of several toxic heavy metals (Pb, Cd, Co, Ni, Zn and Cu) by the exopolysaccharide (EPS) produced by Paenibacillus jamilae, a potential biosorbent for metal remediation and recovery was studied. Firstly, the biochemical composition of this bacterial
polymer was determined. Glucose was the most abundant neutral sugar, followed by galactose, rhamnose, fucose and mannose.
The polymer presented a high content of uronic acids (28.29%), which may serve as binding sites for divalent cations. The
presence of carboxylic groups was also detected by infrared spectroscopy. The EPS presented an interesting affinity for Pb
in comparison with the other five metals. Lead biosorption (303.03 mg g−1) was tenfold higher (in terms of mg of metal adsorbed per gram of EPS) than the biosorption of the rest of metals. Biosorption
kinetics, the effect of pH and the effect of competitive biosorption were determined. Finally, we found that the EPS was able
to precipitate Fe(III), but the EPS-metal precipitate did not form with Fe(II), Pb(II), Cd(II), Co(II), Ni(II), Cu(II) and
Zn(II). 相似文献
3.
Adeline Su Yien Ting Chuan Chun Choong 《World journal of microbiology & biotechnology》2009,25(8):1431-1437
In our study, we isolated the isolate Trichoderma SP2F1 from sediment samples from the Penchala River, heavily contaminated with effluents from nearby industrial areas. Qualitative
and quantitative screening using plate and broth assay, respectively, supplemented with various concentrations of Cu(II) showed
the isolate was able to tolerate 6 mM CuSO4, although growth was also detected in broths with 10 mM CuSO4. Trichoderma spp. was able to remove Cu(II) in aqueous solutions in both viable and non-viable cell forms. Bioaccumulation capacity of
viable SP2F1 cells removed 19.60 mg g−1 of Cu(II) after 168 h incubation, while the maximum Cu(II) biosorption capacity for non-viable SP2F1 cells was 28.75 mg g−1 of Cu(II). Results here showed that Trichoderma spp isolate SP2F1 has good potential for application in Cu(II) removal, can be used to treat sewage waste by applying either
in viable or non-viable cell forms. 相似文献
4.
Zanaty R. Komy Rabei M. Gabar Ahmed A. Shoriet Rehab M. Mohammed 《World journal of microbiology & biotechnology》2006,22(9):975-982
Summary The ability of Pseudomonas
aeruginosa to accumulate Cd(II) ions from wastewater industries was experimentally investigated and mathematically modelled. From the potentiometric titration and non-ideal competitive analysis (NICA) model, it was found that the biomass contains three acidic sites. The values of proton binding (pK
i
=1.66±3.26×10−3, 1.92±1.63×10−4 and 2.16±3.79×10−4) and binding constant of cadmium metal ions (pK
M1=1.99±2.45×10−3 and pK
M2=1.67±4.08×10−3) on the whole surface of biomass showed that protonated functional groups and biosorption of Cd(II) ions could be attributed to a monodentate binding to one acidic site, mainly the carboxylic group. From the isothermal sorption experimental data and Langmuir model, it was also found that the value of Langmuir equilibrium (pK
f) constant is 2.04±2.1×10−5 suggesting that the carboxyl group is the main active binding site. In addition, results showed that the maximum cadmium capacity (q
max) and affinity of biomass towards cadmium metal ions (b) at pH 5.1 and 20 min were 96.5±0.06 mg/g and 3.40×10−3± 2.10×10−3, respectively. Finally, interfering metal ions such as Pb(II), Cu(II), Cr(III), Zn(II), Fe(II), Mn(II), Ca(II) and Mg(II) inhibited Cd(II) uptake. Comparing the biosorption of Cd(II) by various Pseudomonas isolates from contaminated environment samples (soil and sewage treatment plant) showed that maximum capacities and equilibrium times were different, indicating that there was a discrepancy in the chemical composition between biomasses of different strains. 相似文献
5.
Heavy metal sorption by released polysaccharides and whole cultures of two exopolysaccharide-producing cyanobacteria 总被引:1,自引:0,他引:1
The metal removal capacity of cultures of two capsulated, exopolysaccharide-producing cyanobacteria, Cyanospira capsulata and Nostoc PCC7936, were tested using copper (II) as the model metal. C. capsulata cultures removed the greatest amount of copper, with a maximum per unit of biomass (q
max) of 115.0±5.1 mg copper g−1 of protein, compared with 85.0±3.2 removed with Nostoc PCC7936 cultures. Water solutions of pure polysaccharides (RPSs) released into the culture medium by C. capsulata and Nostoc PCC7936 achieved q
max values of 20.2±0.8 mg g−1 copper per polysaccharide dry weight with C. capsulata RPS and 11.0±1.5 mg g−1 with Nostoc PCC7936 RPS. Cultures of the two cyanobacteria also removed Zn (II) and Ni (II), in both single-metal systems and in multimetal
systems with Cu; in the various single-metal systems more copper was removed than Zn or Ni, while in the multimetal systems
a smaller amount of each individual metal was removed but the overall amount of all metal ions sorbed or the amount of copper
sorbed in the copper-only system was almost the same with C. capsulata, and slightly higher with Nostoc PCC7936. 相似文献
6.
Microbial extracellular polymeric substances (EPS) are potential biosorbents for metal remediation and recovery. The Langmuir and Freundlich kinetics of Mn(II) binding by the EPS from a novel Mn(II) oxidising strain of Rhizobium etli were determined. Maximum manganese specific adsorptions (q
max) decreased in the sequence: sulphate (62 mg Mn per g EPS) > nitrate (53 mg g–1) > chloride (21 mg g–1). Consideration of the anion during kinetic studies is usually neglected but is important in providing more practical and comparable data between different biosorbent systems. 相似文献
7.
Sang Eun Oh Sedky H. A. Hassan Jin Ho Joo 《World journal of microbiology & biotechnology》2009,25(10):1771-1778
Biosorptive capacity of Pb(II), Cd(II) and Cu(II) by lyophilized cells of Pseudomonas stutzeri was investigated based on Langmuir and Freundlich isotherms. Biosorptive capacity for Pb(II), Cd(II) and Cu(II) decreased
with an increase of metal concentration, reaching 142, 43.5 and 36.2 mg/g at initial concentration of 300 mg/l, respectively.
Biosorption capacity for metal ions increased with increasing pH. The optimum pH for biosorption rate of Cd(II) and Cu(II)
were 5.0, and 6.0 for Pb(II) biosorption. The experimental data showed a better fit with the Langmuir model over the Freundlich
model for metal ions throughout the range of initial concentrations. The maximum sorptive capacity (q
max) obtained from the Langmuir equation for Pb(II), Cd(II) and Cu(II) were 153.3 (r
2
= 0.998), 43.86 (r
2
= 0.995), and 33.16 (r
2
= 0.997) for metal ions, respectively. The selectivity order for metal ions towards the biomass of P. stutzeri was Pb(II) > Cd(II) > Cu(II) for a given initial metal ions concentration. The interactions between heavy metals and functional
groups on the cell wall surface of bacterial biomass were confirmed by FTIR analysis. The results of this study indicate the
possible removal of heavy metals from the environment by using lyophilized cells of P. stutzeri. 相似文献
8.
The model couples stomatal conductance (g
s) and net photosynthetic rate (P
N) describing not only part of the curve up to and including saturation irradiance (I
max), but also the range above the saturation irradiance. Maximum stomatal conductance (g
smax) and I
max can be calculated by the coupled model. For winter wheat (Triticum aestivum) the fitted results showed that maximum P
N (P
max) at 600 μmol mol−1 was more than at 350 μmol mol−1 under the same leaf temperature, which can not be explained by the stomatal closure at high CO2 concentration because g
smax at 600 μmol mol−1 was less than at 350 μmol mol−1. The irradiance-response curves for winter wheat had similar tendency, e.g. at 25 °C and 350 μmol mol−1 both P
N and g
s almost synchronously reached the maximum values at about 1 600 μmol m−2 s−1. At 25 °C and 600 μmol mol−1 the I
max corresponding to P
max and g
smax was 2 080 and 1 575 μmol m−2 s−1, respectively. 相似文献
9.
Experiments were conducted studying the removal of Cd2+ from water via biosorption using Rhodotorula sp. Y11. The effects of temperature and initial pH of the solution on biosorption were studied. Caustic and heat treatments showed different influences on the biosorption capacity, and the highest metal uptake value (19.38 mg g−1) was obtained by boiling treated yeast cells. The presence of competing cations, such as Ag+, Cu2+, and Mg2+, except Na+ ions, significantly interfered with the metal uptake. Results indicate that the Langmuir model gave a better fit to the experimental data than the Freundlich equation. The q
10 value was 11.38 mg g−1 for Cd2+ uptake by Y11. Chemical modifications of the biomass demonstrated that carboxyl and amide groups play an important role in Cd2+ biosorption. 相似文献
10.
The kinetic parameters Km and Vmax for urea uptake by Melosira italica were determined at 160 μeinsteins m−2 s−1 and in the dark. The transport systems showed an affinity for the substrate and a storing capacity in the dark (Km = 65.07 μM; Vmax = 2.18 nmoles 105 cells −1 h−1) greater than under 160 μE m−2 s −1 (Km = 111.2 μM; Vmax = 1.11 nmoles 105 cells−1 h−1). Similarly, a reduction in consumption rate of urea under increasing photon flux densities was observed. The use of an inhibitor
(potassium cyanide) indicated that the uptake process requires metabolic energy. That urea transport is more important in
darkness, may constitute a survival strategy in which this compound is utilized by cells mainly during heterotrophic growth. 相似文献
11.
Durmaz-Sam S Sayar NA Topal-Sarikaya A Sayar AA 《Bioprocess and biosystems engineering》2011,34(8):997-1005
The potential of the dried yeast, wild-type Schizosaccharomyces pombe, to remove Ni(II) ion was investigated in batch mode under varying experimental conditions including pH, temperature, initial
metal ion concentration and biosorbent dose. Optimum pH for biosorption was determined as 5.0. The highest equilibrium uptake
of Ni(II) on S. pombe, q
e, was obtained at 25 °C as 33.8 mg g−1. It decreased with increasing temperature within a range of 25–50 °C denoting an exothermic behaviour. Increasing initial
Ni(II) concentration up to 400 mg L−1 also elevated equilibrium uptake. No more adsorption took place beyond 400 mg L−1. Equilibrium data fitted better to Langmuir model rather than Freundlich model. Sips, Redlich–Peterson, and Kahn isotherm
equations modelled the investigated system with a performance not better than Langmuir. Kinetic model evaluations showed that
Ni(II) biosorption process followed the pseudo-second order rate model while rate constants decreased with increasing temperature.
Gibbs free energy changes (ΔG°) of the system at 25, 30, 35 and 50 °C were found as −1.47E + 4, −1.49E + 4, −1.51E + 4, and −1.58E + 4 J mol−1, respectively. Enthalpy change (ΔH°) was determined as −2.57E + 3 J mol−1 which also supports the observed exothermic behaviour of the biosorption process. Entropy change (ΔS°) had a positive value (40.75 J mol−1 K−1) indicating an increase in randomness during biosorption process. Consequently, S. pombe was found to be a potential low-cost agent for Ni(II) in slightly acidic aqueous medium. In parallel, it has been assumed
to act as a separating agent for Ni(II) recovery from its aqueous solution. 相似文献
12.
Arifa Tahir Rabia Shehzadi Bushra Mateen Saleh Univerdi Ozer Karacoban 《Engineering in Life Science》2009,9(6):462-467
In this study, Ni (II) biosorption capacity of immobilized cells of Bacillus sp. was investigated. Biosorption of Ni (II) was carried out in batch experiments and the important environmental conditions were optimized. The uptake of metal was rapid, and equilibrium was attained within 270 min. Bacillus strains (ten cultures) were isolated from nickel electroplating effluent by heat shock method. These isolates were grown up in nutrient broth supplemented with Ni (II)(50 mg/L). The culture, exhibiting maximum biosorption capacity (qmax: 118 mg/g), was selected and labeled Bacillus Bio‐4. In order to develop an economical biosorption process cell mass of Bacillus, Bio‐4 was immobilized in Na‐alginate. It was concluded from the results that biosorption of nickel is highly dependent on the type of sorbent and experimental conditions employed. Our results demonstrate that 6.0 mg immobilized cells (18 mg cell biomass in 3.0 mL of 1% Na alginate) had a maximum biosorption capacity of 113 mg Ni(II) per liter of suspension at pH 8.0, 100 rpm and 25°C. The Ni (II) removal was estimated to be 97.4%. 相似文献
13.
Alicia Suazo-Madrid Liliana Morales-Barrera Erick Aranda-García Eliseo Cristiani-Urbina 《Journal of industrial microbiology & biotechnology》2011,38(1):51-64
The present study reports the feasibility of using Rhodotorula glutinis biomass as an alternative low-cost biosorbent to remove Ni(II) ions from aqueous solutions. Acetone-pretreated R. glutinis cells showed higher Ni(II) biosorption capacity than untreated cells at pH values ranging from 3 to 7.5, with an optimum
pH of 7.5. The effects of other relevant environmental parameters, such as initial Ni(II) concentration, shaking contact time
and temperature, on Ni(II) biosorption onto acetone-pretreated R. glutinis were evaluated. Significant enhancement of Ni(II) biosorption capacity was observed by increasing initial metal concentration
and temperature. Kinetic studies showed that the kinetic data were best described by a pseudo-second-order kinetic model.
Among the two-, three-, and four-parameter isotherm models tested, the Fritz-Schluender model exhibited the best fit to experimental
data. Thermodynamic parameters (activation energy, and changes in activation enthalpy, activation entropy, and free energy
of activation) revealed that the biosorption of Ni(II) ions onto acetone-pretreated R. glutinis biomass is an endothermic and non-spontaneous process, involving chemical sorption with weak interactions between the biosorbent
and Ni(II) ions. The high sorption capacity (44.45 mg g−1 at 25°C, and 63.53 mg g−1 at 70°C) exhibited by acetone-pretreated R. glutinis biomass places this biosorbent among the best adsorbents currently available for removal of Ni(II) ions from aqueous effluents. 相似文献
14.
Kiviharju K Moilanen U Leisola M Eerikäinen T 《Applied microbiology and biotechnology》2007,73(6):1267-1274
The behavior of Streptomyces peucetius var. caesius N47 was studied in a glucose limited chemostat with a complex cultivation medium. The steady-state study yielded the characteristic
constants μ
max over 0.10 h−1, Y
XS 0.536 g g−1, and mS 0.54 mg g−1 h−1. The product of secondary metabolism, ɛ-rhodomycinone, was produced with characteristics Y
PX 12.99 mg g−1 and m
P 1.20 mg g−1 h−1. Significant correlations were found for phosphate and glucose consumption with biomass and ɛ-rhodomycinone production. Metabolic
flux analysis was conducted to estimate intracellular fluxes at different dilution rates. TCA, PPP, and shikimate pathway
fluxes exhibited bigger values with production than with growth. Environmental perturbation experiments with temperature,
airflow, and pH changes on a steady-state chemostat implied that an elevation of pH could be the most effective way to shift
the cells from growing to producing, as the pH change induced the biggest transient increase to the calculated ɛ-rhodomycinone
flux. 相似文献
15.
Zn biosorption by Rhizopus arrhizus and other fungi 总被引:1,自引:0,他引:1
J. L. Zhou 《Applied microbiology and biotechnology》1999,51(5):686-693
Biosorption of zinc ions by inactivated fungal mycelia was studied. Of the six fungal species, Rhizopus arrhizus, Mucor racemosus, Mycotypha africana, Aspergillus nidulans, Aspergillus niger and Schizosaccharomyces pombe, R. arrhizus exhibited the highest capacity (Q
max = 213 μmol g−1 dry weight). Further experiments with different cellular fractions of R. arrhizus showed that Zn was predominantly bound to cell-wall chitin and chitosan (Q
max = 312 μmol g−1 dry weight). Adsorption data were best modelled by the Langmuir isotherm, although they can be modelled by the Freundlich
equation as well at relatively low aqueous concentrations. Biosorption generally decreased with increase in biosorbent particle
size and its concentration. Low pH reduced Zn sorption, because of the strong competition from hydrogen ions for binding sites
on fungi. The presence of ligands reduced metal uptake, chiefly by forming metal complexes of a less biosorbable nature.
Received: 2 November 1998 / Received revision: 12 January 1999 / Accepted: 17 January 1999 相似文献
16.
Candida utiilis NRRL Y-900 was grown on pineapple cannery waste as the sole carbon and energy source in a chemostat at dilution rates ranging
between 0.05 and 0.65 h−1 to determine the growth kinetics. The cell yield coefficient varied with dilution rate and a maximum value of 0.662 ± 0.002
gx/gcarb was obtained at a dilution rate of 0.4 h−1. At steady state, the concentrations of carbohydrate, reducing sugar, and chemical oxygen demand (COD) appeared to follow
Monod kinetics. At maximum specific growth rate (μmax) 0.65 h−1, the saturation constants for carbohydrate, reducing sugar and COD were 0.51 ± 0.02 gcarb/1, 0.046 ± 0.003 grs/1, and 1.036 ± 0.001 gCOD/1, respectively. Maximum biomass productivity (Q
x max) 2.8 ± 0.03 gx/1 h was obtained at a dilution rate of 0.5 h−1. At this dilution rate, only 71.0 ± 0.41% COD was removed whereas at a dilution rate of 0.1 h−1, 98.2 ± 0.35% reduction in COD was achieved. At a dilution rate of 0.4 h−1, the optimal yeast productivity and reduction in COD were 2.7 ± 0.13 gp/1 h, and 84.2 ± 0.42%, respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Çiğdem Ay Asiye Safa Özcan Yunus Erdoğan 《International journal of phytoremediation》2017,19(4):327-339
The aim of the present study was to enhance the biosorption capacity of a waste biomass of Punica granatum L. peels (PGL) using various chemical modification agents. Among these agents, hexamethylenediamine (HMDA) indicated the best performance with regard to the improvement of lead(II) ions removal from aqueous solution. The characterization of HMDA-modified P. granatum L. peels (HMDA-PGL) was achieved by using elemental analysis, FT-IR, thermogravimetric (TG) analysis and zeta potential measurement techniques. Based on FT-IR study, the chemical modification of P. granatum L. peels take place with its carboxyl, carbonyl, hydroxyl, etc. groups and these groups are responsible for the biosorption of lead(II) ions onto modified biomass. Biosorption equilibrium and kinetic data fitted well the Langmuir isotherm and the pseudo-second-order kinetic models, respectively. The highest biosorption capacity obtained from Langmuir isotherm model was 371.36 mg g?1. Biosorption process was spontaneous and endothermic in nature according to the thermodynamic results and it quickly reached the equilibrium within 60 minutes. The validity of kinetic models used in this study can be quantitatively tested by using a normalized standard deviation Δq(%). 相似文献
18.
Sorption of Cu(II) and Cd(II) by extracellular polymeric substances (EPS) from Aspergillus fumigatus
Yurong Yin Yongyou Hu Fen Xiong 《International biodeterioration & biodegradation》2011,65(7):1012-1018
Sorption of Cu(II) and Cd(II) onto the extracellular polymeric substances (EPS) produced by Aspergillus fumigatus was investigated for the initial pH of the solution, EPS concentrations, contact time, NaCl concentration, initial metal ion concentration and the presence of other ions in the solution. The results showed that the adsorption of metal ions was significantly affected by pH, EPS concentrations, initial metal concentration, NaCl concentration and co-ions. The sorption of Cu(II) and Cd(II) increased with increasing pH and initial metal ion concentration but decreased with an increase in the NaCl concentration. The maximum sorption capacities of A. fumigatus EPS calculated from the Langmuir model were 40 mg g−1 EPS and 85.5 mg g−1 EPS for Cu(II) and Cd(II), respectively. The binary metal sorption experiments showed a selective metal binding affinity in the order of Cu(II) > Pb(II) > Cd(II). Both the Freundlich and Langmuir adsorption models described the sorption of Cu(II) and Cd(II) by the EPS of A. fumigatus adequately. Fourier transform infrared spectroscopy (FTIR) analysis revealed that carboxyl, amide and hydroxyl functional groups were mainly correlated with the sorption of Cu(II) and Cd(II). Energy dispersive X-ray (EDX) system analysis revealed that the ion-exchange was an important mechanism involved in the Cu(II) and Cd(II) sorption process taking place on EPS. 相似文献
19.
The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution
delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried
out at the optimal pH 5.0. The metal removal rates were conspicuously rapid wherein 90% of the total sorption occurred within
90 min. Biomass treated with CaCl2 demonstrated the highest potential for the sorption of the metal ions with the maximum uptake capacities i.e. 1.71 and 1.79 mmol g−1 for Cd(II) and Pb(II), respectively. Kinetic data were satisfactorily manifested by a pseudo-second order chemical sorption
process. The process mechanism consisting of both surface adsorption and pore diffusion was found to be complex. The sorption
data have been analyzed and fitted to sorption isotherm of the Freundlich, Langmuir, and Redlich–Peterson models. The regression
coefficient for both Langmuir and Redlich–Peterson isotherms were higher than those secured for Freundlich isotherm implying
that the biosorption system is possibly monolayer coverage of the L. variegata surface by the cadmium and lead ions. FT-IR studies revealed that Cd(II) and Pb(II) binding to L. variegata occurred primarily through biomass carboxyl groups accompanied by momentous interactions of the biomass amino and amide groups.
In this study, we have observed that L. variegata had maximum biosorption capacity for Cd(II) and Pb(II) reported so far for any marine algae.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
In the present paper, the possibility of the application of marine macroalga Ulva (Enteromorpha) prolifera, as microelemental feed supplement for livestock, was evaluated. The concept was based on two facts: the natural macroalga
contains high concentrations of microelements and there is a possibility to greatly increase this content via biosorption.
In order to characterize the biosorption process of metal ions by U. prolifera, preliminary experiments were conducted with Cr(III) ions. The effect of temperature, pH and the biomass concentration on
the equilibrium of biosorption was investigated. For further experiments (biosorption of Mn(II), Zn(II), Cu(II), Co(II)),
the following experimental conditions were chosen: pH 5, 25°C, the biomass concentration 1.0 g l−1. Equilibrium of the biosorption process could be described by the Langmuir equation. The theoretical maximum biosorption
capacity was also determined by potentiometric titration of the biomass. The investigation of the external structure of the
macroalga and atomic concentration of elements on the surface of the biomass was analyzed using scanning electron microscopy.
The content of microelements in the biomass after biosorption increased 110,555; 44,228; 21,177; 2,281 and 1,458 times for
Co(II), Cr(III),Cu(II), Zn(II), Mn(II), respectively. Therefore, biomass of U. prolifera enriched with individual microelements, mixed in the proper proportion could be used as feed supplement in animal feeding
to cover the nutrient requirements for microelements. 相似文献