Biosorption of heavy metals by Saccharomyces cerevisiae

Abundant and common yeast biomass has been examined for its capacity to sequester heavy metals from dilute aqueous solutions. Live and non-living biomass of Saccharomyces cerevisiae differs in the uptake of uranium, zinc and copper at the optimum pH 4–5. Culture growth conditions can influence the biosorbent metal uptake capacity which normally was: living and non-living brewer's yeast: U > Zn > Cd > Cu; non-living baker's yeast: Zn > (Cd) > U > Cu; living baker's yeast: Zn > Cu (Cd) > U. Non-living brewer's yeast biomass accumulated 0.58 mmol U/g. The best biosorbent of zinc was non-living baker's yeast ( 0.56 mmol Zn/g). Dead cells of S. cerevisiae removed approximately 40% more uranium or zinc than the corresponding live cultures. Biosorption of uranium by S. cerevisiae was a rapid process reaching 60% of the final uptake value within the first 15 min of contact. Its deposition differing from that of other heavy metals more associated with the cell wall, uranium was deposited as fine-needle-like crystals both on the inside and outside of the S. cerevisiae cells.     

Biosorption of heavy metals by distillery-derived biomass

Biomass derived from the Old Bushmill's Distillery Co. Ltd., Northern Ireland was harvested and examined for its ability to function as a biosorbent for metals such as Cu, Zn, Fe, Pb and Ag. Binding studies were carried out using biosorption isotherm analysis. Although the material had previously been shown to be capable of efficient U biosorption, its affinity for Cu, Zn, Fe was lower. However, binding studies with Pb demonstrated that it had a maximum biosorption capacity for that metal of 189?mg/g dry weight of the biomass. In addition, the biomass exhibited a maximum biosorption capacity of 59?mg/g dry weight for Ag and this compared very favourably with previously quoted values for other industrial sources of Saccharomyces cerevisiae. On the basis of the biosorption isotherm analyses carried out in this study, preference for this series of metals by the biomass was found to be Pb?>?U?>?Ag?>?Zn?≥?Fe?>?Cu.     

解脂假丝酵母对重金属工业废水的吸附特性

利用解脂假丝酵母对Cr(Ⅵ)、Ni(Ⅱ)和Cu(Ⅱ)共存的模拟重金属废水及3种实际重金属废水进行了微生物吸附,结果表明,pH、吸附时间和菌浓度等均是显著的影响因素.Cr(Ⅵ)、Ni(Ⅱ)和Cu(Ⅱ)的去除均符合准一级和准二级动力学模型,其中准二级模型的拟合效果最理想,证明该菌种对重金属的吸附包括了多个步骤,其中化学吸附是限速步骤.解脂假丝酵母对共存重金属的生物吸附效果理想,1g·L^-1菌体在120min时,对18.7～37.86mg·L^-1Cr、2.39～9.21mg·L^-1Cu、2.27～9.87mg·L^-1Ni和0.43～1.32mg·L^-1Zn的去除率分别为81.6%～84.6%、84.0%～100%、84.1%～100%和93.9%～100%.菌体的蛋白质、脂质和多糖均参与了重金属吸附,起作用的主要功能团是-OH、-NH₂、-CH₂、-CH₃、-COOH、-CHO、C=C、-PO₄^3-和-SO₃H.     

Biosorption of heavy metals by Saccharomyces cerevisiae: a review

Heavy metal pollution has become one of the most serious environmental problems today. Biosorption, using biomaterials such as bacteria, fungi, yeast and algae, is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration complex wastewaters containing heavy metal(s) in the order of 1 to 100 mg/L. Among the promising biosorbents for heavy metal removal which have been researched during the past decades, Saccharomyces cerevisiae has received increasing attention due to the unique nature in spite of its mediocre capacity for metal uptake compared with other fungi. S. cerevisiae is widely used in food and beverage production, is easily cultivated using cheap media, is also a by-product in large quantity as a waste of the fermentation industry, and is easily manipulated at molecular level. The state of the art in the field of biosorption of heavy metals by S. cerevisiae not only in China, but also worldwide, is reviewed in this paper, based on a substantial number of relevant references published recently on the background of biosorption achievements and development. Characteristics of S. cerevisiae in heavy metal biosorption are extensively discussed. The yeast can be studied in various forms for different purposes. Metal-binding capacity for various heavy metals by S. cerevisiae under different conditions is compared. Lead and uranium, for instances, could be removed from dilute solutions more effectively in comparison with other metals. The yeast biosorption largely depends on parameters such as pH, the ratio of the initial metal ion and initial biomass concentration, culture conditions, presence of various ligands and competitive metal ions in solution and to a limited extent on temperature. An assessment of the isotherm equilibrium model, as well as kinetics was performed. The mechanisms of biosorption are understood only to a limited extent. Elucidation of the mechanism of metal uptake is a real challenge in the field of biosorption. Various mechanism assumptions of metal uptake by S. cerevisiae are summarized.     

Biosorption of heavy metals in upflow sludge columns

The present study was carried out for evaluating the retention behavior of sanitary sewage and sand in relation to chromium and nickel ions in upflow reactors. It was found that the sludge presented a greater assimilation of the metals studied when compared to the inert material, probably due to the presence of anionic groups, which favors adsorption and complexation processes. Thermal analyses of the samples showed a shift in the decomposition peaks of the "in natura" sludge, when compared with those of the samples spiked with the metals, confirming the possibility of interactions between the heavy metals and the anionic groups present in the sludge.     

茶废弃物对溶液中重金属的生物吸附研究进展

茶废弃物是农业固体废弃物的一个重要组成部分,来源广泛,数量庞大.由于其具有吸附特性,利用茶废弃物作吸附剂去除废水中的重金属受到了国内外学者的广泛关注.本文从影响因素、吸附机理、吸附剂制备和脱附再生等方面综述了茶废弃物吸附去除溶液中重金属的最新研究进展,认为吸附机理、制备、脱附再生、工艺参数和后处理等是今后实现茶废弃物吸附剂工业化应用的主要研究方向.     

Biosorption of heavy metals from aqueous solutions with tobacco dust

A typical lignocellulosic agricultural residue, namely tobacco dust, was investigated for its heavy metal binding efficiency. The tobacco dust exhibited a strong capacity for heavy metals, such as Pb(II), Cu(II), Cd(II), Zn(II) and Ni(II), with respective equilibrium loadings of 39.6, 36.0, 29.6, 25.1 and 24.5 mg of metal per g of sorbent. Moreover, the heavy metals loaded onto the biosorbent could be released easily with a dilute HCl solution. Zeta potential and surface acidity measurements showed that the tobacco dust was negatively charged over a wide pH range (pH > 2), with a strong surface acidity and a high OH⁻ adsorption capacity. Changes in the surface morphology of the tobacco dust as visualized by atomic force microscopy suggested that the sorption of heavy metal ions on the tobacco could be associated with changes in the surface properties of the dust particles. These surface changes appeared to have resulted from a loss of some of the structures on the surface of the particles, owing to leaching in the acid metal ion solution. However, Fourier transform infrared spectroscopy (FTIR) showed no substantial change in the chemical structure of the tobacco dust subjected to biosorption. The heavy metal uptake by the tobacco dust may be interpreted as metal–H ion exchange or metal ion surface complexation adsorption or both.     

Biosorption of heavy metals using whole mold mycelia and parts thereof.

Biosorption of heavy metals was carried out using whole mycelia and selected components of Aspergillus niger, Rhizopus oryzae and Mucor rouxii. Binding of copper, cadmium, nickel and zinc was considerably improved by treating the cell wall fraction with 4 M NaOH at 121 degrees C. Chitosan contributed most to the biosorptive capacity. 0.96 mmol copper was bound by 1 g of the treated mycelium of M. rouxii DSM 1191.     

Biosorption of precious metals

Biosorption has emerged as a low-cost and often low-tech option for removal or recovery of base metals from aqueous wastes. The conditions under which precious metals such as gold, platinum and palladium are sorbed by biomass are often very different to those under which base metals are sorbed. This, coupled with the increasingly high demand for precious metals, drives the increase in research into efficient recovery of precious metal ions from all waste material, especially refining wastewaters. Common biosorbents for precious metal ions include various derivatives of chitosan, as well as other compounds with relatively high surface amine functional group content. This is generally due to the ability of the positively charged amine groups to attract anionic precious metal ions at low pH. Recent research regarding the biosorption of some precious metals is reviewed here, with emphasis on the effects of the biosorption environment and the biosorption mechanisms identified.     

The epifaunal communities of Pelvetia canaliculata and Fucus spiralis

The distribution, size and abundance of Pelvetia canaliculata (L.) and Fucus spiralis L. and the epifaunal communities associated with these two high shore fucoid algae have been studied at several contrasting sites in North Wales. Several environmental parameters were measured at each site and correlated with the distribution of the algae and their associated fauna. These weeds, which occur in perhaps the harshest zone of the shore, support exceedingly impoverished epifaunal communities in which the amphipod Hyale nilssoni (Rathke), small littorinids and acarines predominate. This contrasts markedly with the extremely diverse epifaunal communities associated with algae situated lower in the intertidal zone.     

Biosorption behavior of heavy metals in bioleaching process of MSWI fly ash by Aspergillus niger

In this study, it was considered that the biosorption of heavy metals by biomass might occur during the bioleaching of fly ash. This work is focused on the biosorption behavior of Al, Fe, Pb and Zn by Aspergillus niger during the bioleaching process. The fungal biomass was contacted with heavy metals solution which extracted from fly ash by using gluconic acid as leaching agent. The equilibrium time for biosorption was about 120 min. The biosorption experiment data at initial pH 6.5 was used to fit the biosorption kinetics and isotherm models. The results indicated that the biosorption of Al, Fe and Zn by A. niger biomass were well described by the pseudo-first order kinetic model. The pseudo-second order kinetic model was more suitable for that of Pb. The Langmuir isotherm model could well describe the biosorption of Fe, Pb and Zn while the Freundlich model could well describe the biosorption of Al. Furthermore, the biosorption of metal ions decreased evidently in the presence of fly ash as compared to that in the absence of fly ash. This research showed that although the biomass sorption occurred during the bioleaching process, it did not inhibit the removal of Al, Fe, Pb and Zn evidently from fly ash.     

Biosorption of heavy metals by Bacillus thuringiensis strain OSM29 originating from industrial effluent contaminated north Indian soil

The study was navigated to examine the metal biosorbing ability of bacterial strain OSM29 recovered from rhizosphere of cauliflower grown in soil irrigated consistently with industrial effluents. The metal tolerant bacterial strain OSM29 was identified as Bacillus thuringiensis following 16S rRNA gene sequence analysis. In the presence of the varying concentrations (25–150 mgl⁻¹) of heavy metals, such as cadmium, chromium, copper, lead and nickel, the B. thuringiensis strain OSM29 showed an obvious metal removing potential. The effect of certain physico-chemical factors such as pH, initial metal concentration, and contact time on biosorption was also assessed. The optimum pH for nickel and chromium removal was 7, while for cadmium, copper and lead, it was 6. The optimal contact time was 30 min. for each metal at 32 ± 2 °C by strain OSM29. The biosorption capacity of the strain OSM29 for the metallic ions was highest for Ni (94%) which was followed by Cu (91.8%), while the lowest sorption by bacterial biomass was recorded for Cd (87%) at 25 mgl⁻¹ initial metal ion concentration. The regression coefficients obtained for heavy metals from the Freundlich and Langmuir models were significant. The surface chemical functional groups of B. thuringiensis biomass identified by Fourier transform infrared (FTIR) were amino, carboxyl, hydroxyl, and carbonyl groups, which may be involved in the biosorption of heavy metals. The biosorption ability of B. thuringiensis OSM29 varied with metals and was pH and metal concentration dependent. The biosorption of each metal was fairly rapid which could be an advantage for large scale treatment of contaminated sites.     

酿酒酵母吸附重金属离子的研究进展

重金属污染成为当今最重要的环境问题之一。生物吸附法是处理大体积低浓度重金属废水的一种理想方法,近年来有关的研究报道不断增多,但尚未实现工业化应用。酿酒酵母(Saccharomyces cerevisiae)不仅是具有实用潜力的生物吸附剂,也是研究重金属生物吸附机理的良好材料。结合自己的研究成果,总结了酿酒酵母作为生物吸附材料的优点、研究中的表现形式和吸附性能,重点讨论了酿酒酵母生物吸附机理,介绍了等温吸附平衡模型和动力学模型在酵母生物吸附中的应用情况。最后提出生物吸附进一步的研究方向。     

Inhibition of photosynthesis by heavy metals

Inhibition of photosynthesis by heavy metals is well documented. In this review the results are compared between in vitro experiments on isolated systems (chloroplasts, enzymes ­.), experiments on excised leaves and intact plants and algae in vivo. In vitro experiments suggest potential sites of heavy metal interaction with photosynthesis at several levels of organisation, which are not necessarily confirmed in vivo. Analytical data on subcellular heavy metal level are generally missing to discuss their mechanism of action in the intact organism. In the field factors such as soil characteristics and air pollution have to be taken into account for assessing the mechanism of action of heavy metals on photosynthesis in plants, growing in a polluted erea.paper presented at the FESPP meeting in Strasbourg (1984)     

Biosorption behavior and mechanism of heavy metals by the fruiting body of jelly fungus (Auricularia polytricha) from aqueous solutions

The aim of this study was to investigate the biosorption characteristics of Cd(2+), Cu(2+), and Pb(2+) by the fruiting body of jelly fungus Auricularia polytricha. Batch experiments were conducted to characterize the kinetics, equilibrium, and mechanisms of the biosorption process. Optimum values of pH?5, biomass dosage 4?g?L(-1), and contact time 60?min provided maximum biosorption capacities of A. polytricha for Cd(2+), Cu(2+), and Pb(2+) of 63.3, 73.7, and 221?mg?g(-1), respectively. The maximum desorption was achieved using 0.05?mol?L(-1) HNO(3) as an elute. The fruiting body was reusable at least for six cycles of operations. The pseudo-second-order model was the best to describe the biosorption processes among the three kinetic models tested. Freundlich and Dubinin-Radushkevich models fitted the equilibrium data well, indicating a heterogeneous biosorbent surface and the favorable chemisorption nature of the biosorption process. A Fourier transform infrared spectroscopy analysis indicated that carboxyl, amine/hydroxyl, amino, phosphoryl, and C-N-C were the main functional groups to affect the biosorption process. Synergistic ion exchange and surface complexation were the dominant mechanisms in the biosorption process. The present work revealed the potential of jelly fungus (fruiting body of A. polytricha) to remove toxic heavy metals from contaminated water.     

Arrested development in Fucus spiralis (Phaeophyceae) germlings exposed to copper

Exposure of Fucus spiralis germlings to precise copper concentrations (0 to 844?nM?Cu²⁺) in chemically defined medium demonstrated a relationship between ultrastructural changes and growth retardation with increasing copper concentration. Electron-translucent vesicles, present in ova, which normally disappear after fertilization, accumulated in germlings exposed to Cu²⁺ above 10.6?nM, suggesting that copper may inhibit a metabolic pathway involved in cell wall formation which is initiated by fertilization. No membrane damage was observed during the exposure period. During a post-exposure period in copper-free medium, recovery occurred (rhizoid extension, apical hair formation) in germlings previously exposed to concentrations below 106?nM?Cu²⁺ and electron-translucent vesicles became granular and disappeared. It is proposed that the electron-translucent vesicles contain a cell wall precursor and that copper inhibits its incorporation into the cell wall, preventing growth and development of the zygote.     

Biosorption of heavy metals by the exopolysaccharide produced by <Emphasis Type="Italic">Paenibacillus jamilae</Emphasis>

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).     

Biosorption of heavy metals by lyophilized cells of <Emphasis Type="Italic">Pseudomonas stutzeri</Emphasis>

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.     

Biosorption and growth inhibition of wetland plants in water contaminated with a mixture of arsenic and heavy metals

The potential of wetland plants as an onsite biosorbent and a biomonitor for combined pollution of arsenic and four heavy metals from non‐point sources was investigated in this study. Ceratophyllum demersum, Hydrilla verticillata, Hydrocharis dubia, and Salvinia natans were exposed to a water containing mixture of As, Cr, Cu, Pb, and Zn. Growth inhibition and biosorption potential of the wetland plants in artificially contaminated conditions were studied. These contaminants significantly reduced the growth of the plants. The tested wetland plants accumulated appreciable amounts of the contaminants in the following order: Pb>Cr>Cu>Zn>As. H. verticillata showed distinct visual change and a high biosorption factor (BSF) rank for As and heavy metals among the plants used in the study. As an unspecific collector of contaminants, it might be useful as a biomonitor and biosorbent in the As and heavy metal‐contaminated aquatic system.