An insight into the mechanism of biosorption of copper by Bacillus polymyxa
01 Jan 2001-International Journal of Environment and Pollution (Inderscience Publishers)-Vol. 15, Iss: 4, pp 448
TL;DR: Electron paramagnetic resonance (EPR) spectroscopy studies indicated that the metal coordinating environment could be either CuN2O2 or CuNO3 chromophores, which may be the result of binding of Cu(II) to oxygen atoms of carboxylic groups of cell wall peptidoglycan and nitrogen atoms of amino-sugars or structural proteins.
Abstract: Our main objective was to isolate bacteria from soil contaminated with effluents from electroplating wastewater and assess their potential to remove copper from the aqueous phase. The strain identified as Bacillus polymyxa accumulated copper inside the cell, where it bound to the cell wall. The intracellular metal accumulation led to the inhibition of dehydrogenases, which is essential for the energy deriving reactions. Addition of thiol group containing compounds, like reduced glutathione, dithiothreitol and mercapto-ethanol, revived the enzyme activity, implicating the sulfhydryl groups as the target of metal action. However, when the cells were exposed to higher concentration of Cu(II), irreversible enzyme denaturation occurred. Desorption with DTT and citrate showed that 82% of the metal was accumulated on cell surface and the contribution from metabolism-dependent intracellular accumulation was only 10-12%. The surface characterization of B. polymyxa indicated the presence of carboxyl, imidazolium, amino and phenolic groups, which might be responsible for metal uptake. Electron paramagnetic resonance (EPR) spectroscopy studies indicated that the metal coordinating environment could be either CuN2O2 or CuNO3 chromophores, which may be the result of binding of Cu(II) to oxygen atoms of carboxylic groups of cell wall peptidoglycan and nitrogen atoms of amino-sugars or structural proteins. This environment got slightly altered after several treatments of B. polymyxa, leading to the formation of CuO4, suggesting the coordination of copper to four oxygen atoms derived from carboxyl groups of peptidoglycan.
Citations
More filters
Book•
13 May 2017
TL;DR: In this article, the authors proposed a method to trap heavy metals in contaminated waters by subjecting biomass to various processes like pretreatment, granulation and immobilization, finally resulting in metal entrapped in bead-like structures.
Abstract: Heavy metals occur in immobilized form in sediments and as ores in nature. However due to various human activities like ore mining and industrial processes the natural biogeochemical cycles are disrupted causing increased deposition of heavy metals in terrestrial and aquatic environment. Release of these pollutants without proper treatment poses a significant threat to both environment and public health, as they are non biodegradable and persistent. Through a process of biomagnification, they further accumulate in food chains. Thus their treatment becomes inevitable and in this endeavor, biosorption seems to be a promising alternative for treating metal contaminated waters. This technology employs various types of biomass as source to trap heavy metals in contaminated waters. The biosorbent is prepared by subjecting biomass to various processes like pretreatment, granulation and immobilization, finally resulting in metal entrapped in bead like structures. These beads are stripped of metal ions by desorption which can be recycled and reused for subsequent cycles. This technology out- performs its predecessors not only due to its cost effectiveness but also in being ecofriendly i.e., where other alternatives fail.
273 citations
04 Apr 2015
TL;DR: Ultimately, to a meaningful and significant extent, the authors can bridge the gap between the horrifying environmental distress and the hostile activities that have been constantly provoked by human kind—by getting these indigenous microorganisms into action.
Abstract: Environmental protection has the foremost importance in the present day life of mankind. Scientists have been researching for technologies naturally available for enhancement of agriculture, management of agricultural waste, etc. Indigenous Microorganisms (IMO’s)-based technology is one such great technology which is applied in the eastern part of world for the extraction of minerals, enhancement of agriculture and waste management. Indigenous microorganisms are a group of innate microbial consortium that inhabits the soil and the surfaces of all living things inside and outside which have the potentiality in biodegradation, bioleaching, biocomposting, nitrogen fixation, improving soil fertility and as well in the production of plant growth hormones. Without these microbes, the life will be wretched and melancholic on this lively planet for the survival of human race. That is why, environmental restoration and safeguarding target via the indigenous microbes in a native manner to turn out the good-for-nothing and useless waste into productive bioresources is the primary concern of this review. Based on the collection sites, the process of collection and isolation methods are different as they may vary from place to place. Ultimately, in this way to a meaningful and significant extent, we can bridge the gap between the horrifying environmental distress and the hostile activities that have been constantly provoked by human kind—by getting these indigenous microorganisms into action.
127 citations
Cites methods from "An insight into the mechanism of bi..."
...Bacillus strains have been widely used in the removal of metals (Pb, Cd, Cu, Ni, Co, Mn, Cr, Zn) from wastewaters (Philip and Venkobachar 2001; Srinath et al. 2003; Kim et al. 2007)....
[...]
TL;DR: It is observed that the presence of transition metal ion, Ag+, Cu2+, or Fe3+, at a concentration of 3 mg L(-1) increases sorption of two nonpolar hydrophobic organic compounds, phenanthrene (PHEN), and 1,2,4,5-tetrachlorobenzene (TeCB) by 1.5-4 times to Gram-negative bacteria Escherichia coli.
Abstract: We observed that the presence of transition metal ion, Ag+, Cu2+, or Fe3+, at a concentration of 3 mg L-1 increases sorption of two nonpolar hydrophobic organic compounds (HOCs), phenanthrene (PHEN), and 1,2,4,5-tetrachlorobenzene (TeCB) by 1.5−4 times to Gram-negative bacteria Escherichia coli. Complexation of transition metals with the deprotonated functional groups (mainly carboxyl) of bacterial cell walls neutralizes the negative charge, making the bacterial surface less hydrophilic and enhancing hydrophobic partition of HOCs. This is evidenced by the fact that the zeta potential (ζ) value of bacteria becomes less negative when a transition metal is present. Furthermore, the observed higher sorption of PHEN than TeCB at low pH (3.8) cannot be fully explained by the pH-dependent hydrophobic effects. The results led us to propose two specific sorption mechanisms for π-donor compounds: cation−π interactions with protonated amines and π H-bonding with protonated carboxyls. The biosorption of PHEN was bes...
59 citations
TL;DR: The results showed that dielectric properties of these cellular components were changed with Cu(2+) treatment in a time- and concentration-dependent way.
Abstract: Dielectric properties of E. coli cells before and after Cu 2+ incubation were investigated by using the dielectric spectroscopic technique. The dielectric spectra are analyzed theoretically by means of the extended three-shell ellipsoidal model, which can reflect the complicated morphological structure of E. coli cell including the outer membrane, the periplasmic space, the inner membrane and the cytoplasm. The results showed that dielectric properties of these cellular components were changed with Cu 2+ treatment in a time- and concentration-dependent way. The permttivity of the outer membrane increased with the incubation time and concentration of Cu 2+ , possibly because polarizability of the outer leaflet of lipopolysaccharides was affected by Cu 2+ . The conductivity of the periplasmic space decreased with the incubation time and concentration of Cu 2+ , possibly due to the damage of peptidoglycan. The decreased permittivity of the inner membrane may be caused by disturbance of the lipid bilayer structure produced by Cu 2+ incubation. The decreased cytoplasmic conductivity may be the consequence of the leakage of K + from it. The cytoplasmic permittivity decreased with Cu 2+ treatment probably because of the leakage of its some components.
43 citations
TL;DR: The human population is increasing day by day and it requires intensifying the existing agricultural production systems as discussed by the authors, but environmental deterioration and unsustainable systems are the consequences of these ways of management.
Abstract: The human population is increasing day by day and it requires intensifying the existing agricultural production systems. The agricultural production is high due to the immense use of synthetic agrochemicals but environmental deterioration and unsustainable systems are the consequences of these ways of management (Armstrong and Taylor, 2014). The environmentally friendly effective microorganisms (EM) have a large number of benefits when they are applied as manure or spray to the field crops (Alluri et al., 2007).
36 citations
Cites methods from "An insight into the mechanism of bi..."
...Bacillus strains have been widely used in the removal of such kind of metals (Pb, Cd, Cu, Ni, Co, Mn, Cr, Zn) from wastewaters (Philip and Venkobachar, 2001; Srinath et al., 2003 and Kim et al., 2007) and also from soil solution if applied there to improve inherent quality and fertility of soil....
[...]
References
More filters
Book•
15 Aug 1990TL;DR: The state of the art in the field of biosorption is reviewed, with many references to recent reviews and key individual contributions, and the composition of marine algae polysaccharide structures, which seem instrumental in metal uptake and binding are discussed.
Abstract: Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-binding capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the metal. Mycelia of the industrial steroid-transforming fungi Rhizopus and Absidia are excellent biosorbents for lead, cadmium, copper, zinc, and uranium and also bind other heavy metals up to 25% of the biomass dry weight. Biosorption isotherm curves, derived from equilibrium batch sorption experiments, are used in the evaluation of metal uptake by different biosorbents. Further studies are focusing on the assessment of biosorbent performance in dynamic continuous-flow sorption systems. In the course of this work, new methodologies are being developed that are aimed at mathematical modeling of biosorption systems and their effective optimization. Elucidation of mechanisms active in metal biosorption is essential for successful exploitation of the phenomenon and for regeneration of biosorbent materials in multiple reuse cycles. The complex nature of biosorbent materials makes this task particularly challenging. Discussion focuses on the composition of marine algae polysaccharide structures, which seem instrumental in metal uptake and binding. The state of the art in the field of biosorption is reviewed in this article, with many references to recent reviews and key individual contributions.
3,388 citations
TL;DR: Isolated walls of Bacillus subtilis Marburg, prepared in a manner which avoided metal contamination other than by the growth medium, were incubated in dilute metal solutions, separated by membrane filtration, and monitored by atomic absorption to give uptake data for 18 metals.
Abstract: Isolated walls of Bacillus subtilis Marburg, prepared in a manner which avoided metal contamination other than by the growth medium, were incubated in dilute metal solutions, separated by membrane filtration (0.22 mum), and monitored by atomic absorption to give uptake data for 18 metals. Substantial amounts of Mg2+, Fe3+, Cu2+, Na+, and K+ (amounts which were often visible as Au3+, and Ni2+ (the higher atomic-numbered elements also visible as electron scattering), and small amounts of Hg2+, Sr2+, Pb2+, and Ag+ were taken into the wall. Some (Li+, Ba2+, Co2+, and Al3+) were not absorbed. Most metals which had atomic numbers greater than 11 and which could be detected by electron microscopy appeared to diffusely stain thin sections of the wall. Magnesium, on the other hand, partitioned into the central region, and these sections of walls resisted ruthenium red staining, which was not true for the other metals. Areas of the walls also acted as nucleation sites for the growth of microscopic elemental gold crystals when incubated in solutions of auric chloride. Retention or displacement of the metals was estimated by a "chromatographic" method using the walls cross-linked by the carbodiimide reaction to adipic hydrazide agarose beads (which did not take up metal but reduced the metal binding capacity of the walls by ca. 1%) packed in a column. When a series of 12 metal solutions was passed through the column, it became evident that Mg2+, Ca2+, Fe3+, and Ni2+ were strongly bound to the walls and could be detected by both atomic absorption and by their electron-scattering power in thin sections, qhereas the other metals were fisplaced or replaced. Partial lysozyme digestion of the walls (causing a 28% loss of a [3H]diaminopimelic acid label) greatly diminished the Mg2+ retention but not that of Ca2+, Fe3+, or Ni2+, indicating that there are select sites for various cations.
522 citations
TL;DR: Uranium accumulated extracellularly on the surfaces of Saccharomyces cerevisiae cells and Pseudomonas aeruginosa occurred intracellularly and was extremely rapid (<10 s), and no response to environmental parameters could be detected.
Abstract: Uranium accumulated extracellularly on the surfaces of Saccharomyces cerevisiae cells. The rate and extent of accumulation were subject to environmental parameters, such as pH, temperature, and interference by certain anions and cations. Uranium accumulation by Pseudomonas aeruginosa occurred intracellularly and was extremely rapid (<10 s), and no response to environmental parameters could be detected. Metabolism was not required for metal uptake by either organism. Cell-bound uranium reached a concentration of 10 to 15% of the dry cell weight, but only 32% of the S. cerevisiae cells and 44% of the P. aeruginosa cells within a given population possessed visible uranium deposits when examined by electron microscopy. Rates of uranium uptake by S. cerevisiae were increased by chemical pretreatment of the cells. Uranium could be removed chemically from S. cerevisiae cells, and the cells could then be reused as a biosorbent.
444 citations
TL;DR: Algal biomass of Sargassum natans and Ascophyllum nodosum outperformed ion exchange resins in sequestering respectively gold and cobalt from solutions and non-living biomass ofSaccharomyces cerevisiae andRhizopus arrhizus exhibited higher metal-uptake capacity than the living biomass for the uptake of copper, zinc, cadmium, uranium.
Abstract: Biosorbent materials are a potential alternative to conventional processes of metal recovery from industrial solutions. Algal biomass ofSargassum natans andAscophyllum nodosum outperformed ion exchange resins in sequestering respectively gold and cobalt from solutions. Non-living biomass ofSaccharomyces cerevisiae andRhizopus arrhizus exhibited higher metal-uptake capacity than the living biomass for the uptake of copper, zinc, cadmium, uranium. The solution pH affected the metal-uptake capacity of the biomass whereas the equilibrium biosorption isotherms were independent of the initial concentration of the metal in the solution. Desorption of the metal from the biosorbent and recycle of the biosorbent have also been demonstrated.
418 citations