Nano bioremediationSubmitted to-Submitted by- Shreya M. Modi. Student of M.phil/p.hD in nanoscience
ABSTRACTNanoscience, Nanotechnology and their applications have altered the face of Science andtechnology. Environmental hazards, Population and pollution is increasing day by day,and it is the great challenge to science and society to solve these problems. Till now,microorganisms are used widely in the process of remediation, but now a daysapplication of nanotechnology and nanoparticals have become boon to solve all theseproblems. Nanoparticals have more advancement than microorganisms. In this termpaper I have just tried to explain the advancement of Nano bioremediation. Using thenanoparticals and nanotechnological instruments it is possible to carry out genetic andprotein engineering of microbial cells which can be used for bioremediation.Immobilization of microbial cells and enzymes with nanoparticals also enhance theprocess of remediation. Apart from this, some microorganisms have ability to synthesizethe nanoparticals which are helpful to the process and also can be recovered for theirapplication in other field. As well as Nanophytoremediation also enhance theremediation process.Key Words- Nanotechnology, Nanoparticals, Bioremediation, Immobilization Nanophytoremediation
NANOSCIENCE AND NANOTECHNOLOGYScience require measurement. Measurement is the language of science. Nanoscaleimplies a scale of measurement that exists at the level of the nanometer.Nanoscience is the study of atoms, molecules, and objects whose size is on the nanometerscale ( 1 - 100 nanometers ).Nanotechnology originates from the Greek word ‘dwarf’.By definition, nanotechnology is the science of microengineering. Microengineering isthe science of engineering that deals with particle manipulation if those particles aresmaller than 100 nanometers. Nanotechnology is a broad and interdisciplinary field dealing with structures andparticles at the Nano scale. Nanotechnology can be defined as “Research and technologydevelopment at the atomic, molecular, or macromolecular levels using a length scale ofapproximately one to one hundred nanometers in any dimension; the creation and use ofstructures, devices and systems that have novel properties and functions because of theirsmall size; and the ability to control or manipulate matter on an atomicscale” (US EPA2007, p 5). The goal of nanotechnogy is to direct atoms and molecules to form desired structures orpatterns with novel functionality at the nanoscale, the physical, chemical, and biologicalproperties of materials differ in fundamental and valuable ways from the properties ofindividuals atoms and molecules or bulk matter.Nanoparticals have significant properties like--Higher Surface Area-Highly active surface bonds-Smaller size of nanoparticals etc… make them more reactive and more sensitive to theenvironment and other fields.Nanotechnology has ability to image, measure, model, and manipulate matter on theNano scale to exploit those properties and functions and also has ability to integrate thoseproperties and functions into systems spanning from nano- to macro-scopic scales.Nanotechnology has been contributing to commercial products for many years. Forexample, nanometer sized carbon improves the mechanical properties of fibers;nanometer silver particals initiates photographic film development.
 Nanotechnology can be applied in so many fields.Now a days the field of nanotechnology is going to become omnipresent asmicroorganisms, because it is applied in almost every field.INTRODUCTIONThe advancement of science and technology have altered our life completely. Bothpopulation and pollution is growing very fast. Sax(1974) stated that “The communalactivities of man as asocial being have created a new order of by products whichincreased in volume at rate faster than population and has resulted in increasingcontamination of the environment where natural purifying activities can no longer keepup with it.” The remediation of contaminants by use of existing technologies is noteffective and efficient to clean up the environment, but now a days the nanotechnologycan be applied in the process of remediation. Nanotechnology itself and nanoparticalshave potential property to solve the environmental problems. They also enhancebioremediation by modifying the activity of microorganisms. In this term paper I haveonly just tried to give something about Nano bioremediation.REMEDIATIONThe act or process of correcting fault or deficiency is known as remediation.ENVIRONMENTAL REMEDIATIONIt deals with the removal of pollution or contaminants from environmental media such assoil, groundwater, sediment or surface water for the protection of environment and livingbeings.BIOREMEDIATION
Bioremediation comes from two words bios means life and remediate means to decipheran issue. The degradation of noxious waste from the environment using microorganismsis called as bioremediation. Microorganisms like bacteria, fungi, algae etc take part inbioremediation. There are many forms of bioremediation they are given as bioleaching,bio-venting, phyto- remediation, land-farming, composting, rhizo-filtration, bio-absorption, bio-augmentation, myco-remediation and bio-reacting. There may be naturalor intrinsic bioremediation.[7,8]NANOBIOREMEDIATIONNano + Bio + RemediationThe use of nanoscience, nanoparticles and nanotechnology to enhance the microbialactivity to remove pollutants, they also enhance Nanobioremediation.Nanobioremediation has the potential not only to reduce the overall coasts of cleaning uplarge-scale contaminated sites, but it can also reduce clean up time.GENETIC MODIFICATION OF MICROBESMicroorganisms have so many advantages for this purpose because they possess manyimportant properties like-Reproduce very rapidly, can be grown in small or vast quantities, easily broken downcapacity, etc...... Bionanotechnology can be observed as "Nanotechnology through Biotechnology" that is, the bio-fabrication of nano-objects, or bi-functional macromolecules usable astools to construct or manipulate nano-objects. Because of their wide physiologicaldiversity, small size, genetic manipulability and controlled culturability, microbial cellsar e ideal producers of a diversity of nanostructures, materials and instruments for Nanosciences, ranging from fully natural products such as viruses, polymers andmagnetosomes, to engineered proteins or protein constructs such as virus-like particles(VLPs), and peptide-displaying phages or cells and tailored metal particlesNanotechnology play very important role in the genetic engineering of microbial gene toenhance its capacity for multipurpose use.Deinococcus radiodurans.This bacterium is currently the most radioactive-resistant organism known on Earth.Its tremendous ability to withstand high doses of radiation well beyond any naturally-occurring levels on the planet have caused it to become the focus of a radioactive wasteclean-up initiative funded by the US Department of Energy (DOE)[11,12,13,15]D. radiodurans shows remarkable genome plasticity. It is able to maintain, replicate andexpress extremely large segments of foreign DNA inserted into its genome by tandemduplication [13,14]. This capability has been exploited recently to show that it canaccommodate and functionally express highly amplified DNA duplication insertionsencoding bioremediation functions
While incapable of degrading actual radioactive elements, genetic engineering of thisorganism to include genes from other organisms for the degradation or immobilization ofmajor heavy metal and organic solvent contaminants found in radioactive dumpsitescould aid the clean-up effort of these sites at a significantly reduced costFor example, the highly characterized merAlocus from Escherichia coli has been clonedinto D. radiodurans [ 11]. merA encodes mercuric ion reductase (MerA), which reduceshighly toxic, thiol-reactive mercuric ion, Hg(II), to much less toxic and nearly inertelemental and volatile Hg(0). Four different D. radiodurans expression systems weredeveloped and used to regulate merA expression by varying its cellular gene dosage. Engineered D. radiodurans strains expressing mer functions could resist andreduce toxic Hg(II) to volatile elemental Hg(0) in the presence of high-levelchronic radiation. Hg(II)-reducing and toluene-metabolizing D. radioduransstrain is also reported.Other metal reducing/resistance functions that have been cloned into D. radiodurans andare being studied include genes from the following organisms that are specific for theindicated metal ions:Desulfovibrio vulgaris (cytc3), U(VI);Ralstoniaeutrophus CH34 (czc), Cd(II), Zn(II), and Co(II); andBacillus thuringiensis, Cr(VI).for introducing into a single D. radiodurans host the many different bioremediating genesystems that will be necessary for cleanup of heterogenous radioactive wasteenvironments. These type of genetic engineering of microorganisms are very beneficialbecause if we use different organisms for different waste clean up, we must have to addsome nutrients, growth factors etc... to fulfill their growth requirements. But here, byapplying nanobioremediation single type of organism can carry out clean up of manywaste products.NANOSCALE BIOPOLYMERS WITH CUSTOMIZABLEPROPERTIES FOR HEAVY METAL REMEDIATIONMetal chelatingpolymers require toxic solvents for synthesis and require ultrafiltration fortheir separation from the solution. • One way of solving this problem to develop metal binding materials that can be recovered by changing the environment like- pH, Temperature etc.. Around them.One such material is nanoscale modified biopolymers which can be manufactured bygenetic and protein engineering of microorganisms which can control the size andarrangement at the molecular level.This table contain some examples of modified microorganisms using nanotechnologyinstrument. Microorganisms Modification Contaminants References Pseudomonas sp. Pathway mono/dichlorobenzoates REINEKE and B13 KNACKMUSS, 1979, 1980
P. putida Pathway 4-ethylbenzoate RAMOS et al., 1987 P. putida KT2442 Pathway RAMOS et al., 1987 PANKE et al., 1998 PANKE et al., 1998 Pathway chloro-, ROJO et al., 1987 methylbenzoates C. testosteroni VP44 Substrate o-, p- HRYWNA et al., Specificity monochlorobiphenyls 1999 Pseudomonas sp. Substrate PCB ERICKSON and LB400 Specificity MONDELLO, 1993 E. coli S ubstrate PCB, benzene, toluene KUMAMMRU et JM109(pSHF1003) Specificity al., 1998 E. coli Regulation TCE, toluene WINTER et al., FM5/pKY287 1989DECOLORIZATION OF THE DYE CONGORED BY AspergillusnigerSILVER NANOPARTICALSRemoval of dyes from industrial waste waters is of global concern because dyes causemany problems in aqueous environments. Dyes may significantly affect photosyntheticactivity in aquatic life because of reduced light penetration and may also be toxic to someaquatic life due to the presence of aromatics, metals, chlorides, etc. The A.niger is allowed to grow in the presence of AgNO3 and incubated in dark, it willform silver nanoparticals within 48 hours which enhance the degradation process ofCongo red dye.A significant decolorization rate was observed for the dye Congo red. The Aspergillusniger silver nanoparticle effectively decolorized85.8%of dye within 24 hour incubationand the dye was fully decolorized within 48 hour of incubation. Whereas the plainculture (Aspergillus niger) was able to degrade only 76%of dye at the same incubationconditions and complete decolorization was observed after 48 hour incubation.(Graph.1)
Graph.1. % of decolorization of the dye Congo red by Aspergillus niger silvernanoparticle and Aspergillus niger (plain culture)REMOVAL OF PHENOLIC POLLUTANTS FROM MUNICIPALWASTE WATER IMMOBILIZED LACCASE ENZYMES USINGNANOPARTICALS4Laccase is generally found in higher plants and fungi but recently it was found in somebacteria such as S.lavendulae, S.cyaneus, and Marinomonas mediterranea[21,22,23]Endocrine disrupting compounds (EDCs) can cause adverse health effects likedevelopmental disorders, birth defects or cancer.One major pathway for EDCs to be released into the environment is through wastewatertreatment plant effluents. Consequently, removal of EDCs from wastewater is of concern.Many EDCs in wastewater are phenolics e.g. bisphenol A (BPA). It has been proposedthat laccase–an enzyme using molecular oxygen as substrate to oxidize phenolicmoieties–could be utilized for the removal of phenolic contaminants from wastewater. Inthe present work laccase of a Thielavia genus has been immobilized on fumed silicananoparticles. The stability and activity of the resulting biocatalysts regarding theremoval of bisphenol A from biologically treated wastewater was assessed and comparedto the activity and stability of free laccase enzymes. Stability of the immobilized laccasewas considerably higher than that of the free enzyme. Approximately 75% of the initialBPA was transformed within 2 hours. The ability to significantly eliminate BPA atenvironmentally relevant concentrations as well as the increased stability of theimmobilized over the free enzymes shows the large potential for laccase-nanoparticleconjugates in municipal wastewater treatment for the elimination of phenoliccontaminants.Apart from this,Mesoporous carbon materials, with their properties such as a large specific surfacearea, a high pore volume, a porosity made up of uniformed mesopores with tunable sizesand higher hydrothermal resistance compared with mesoporous silica materials and othermaterials, have been considered as highly suitable candidates for laccase enzymeisolated from Trametes versicolor and molecule immobilization Magnetic bio-separation technology is a promising technology in the support systemsfor enzyme immobilization, since on the basis of magnetic properties, compared withconventional filtering separation, rapid separation and easy recovery could be reached inexternal magnetic field, and the capital and operation costs could also be reduced The use of laccase enzyme instead of whole organism is very much beneficial processbecause enzyme can be harvested and reused after the process and no need to removemicrobial cells.
NANOTECH COATING CAN ENHANCE ELECTRICITY OUTPUTFROM WASTE WATEREngineers at Oregon State University have discovered that the proper nanotech coatingcould increase the electricity output of wastewater-to-energy production by more than20 times..In producing power from wastewater, bacteria are placed in an anode chamber – wherethey form a biofilm, consume nutrients and grow – to release electronsThe researchers then experimented with the use of new coatings on the anodes ofmicrobial electrochemical cells to generate more electricity from sewage. They found thatcoating graphite anodes with a nanoparticle layer of gold can increase electricityproduction by 20 times, while coatings with palladium produced an increase as well,but not nearly as much.Use of silver nanoparticles to control biofilm formation in aqueous environment and UFmembrane apparatus.Due to increasing tolerance of the biofilm community to antibiotics, biocides andmechanical stress, it has become just as difficult to completely eradicate mature biofilmsas it is to completely avoid the presence of planktonic cells, the origin of the biofilm inthe water. Common treatments to prevent or remove bio fouling include usingdisinfection, minimizing nutrients in the feed or altering surface materials to preventbacterial attachment, or clean-in-place (CIP) to remove mature biofilm by chemical orMechanical shear.Nanoparticles are collection in aggregate of atoms in the range of 1-100 nm with uniquestructure and properties, which are widely used in an increase amount of applications.Silver nanoparticles (Ag-NPs) in particular, provide effective growth inhibition ofvarious microorganisms in suspension and on solid medium.In addition, a few types of filtration membranes and devices like catheter incorporatingsilver nanoparticles have demonstrated anti-biofouling properties.NANOBIOREMEDIATION TO CLEAN UP OIL SPILLImmobilization cells of Ps. mendocina H3, Ps. pseudoalcaligenes H7, Ps. stutzeri H10,Ps.alcaligenes H15, Ps. pseudoalcaligenes H16, Ps. mallei 36K and Micrococcus luteus37 was demonstrated high sorbtional activity carriers.The degrees of attached microbial cells were reached 80-90%.In depend from strain of microorganisms attached to carbonized nanoparticles newnanobiopreparates possesses important properties and may be sorbents of differentmetals, oxidizer oil, aromatic carbohydrates, toluene, herbicide, pesticide and other.For bioremediation of oil contaminated soil is important that carbonizated sorbents itselfmay sorbs oil drops for further oxidation carbohydrates of oil by microbial cells, to besource of mineral compounds and improve condition of soils.Us were investigated oil-oxidative activity nanobiopreparates receiving byimmobilization specific microorganism’s cells on particles carbonizated rice hunk with
nanosize. According results were received different physical and chemical methods ex-situ bioremediation of oil-contamination soil by new nanobioprepates was discovered thattheir destructive activity marked above than free microbial cells.DEGRADATION OF HYDROPHOBIC COMPOUND ENHANCEDBY NANOPARTICALS.Nanoparticals are also being used to increase the bioavailability of hydrophobic ograniccompounds for their enhanced bioremediation.Polymeric nanoparticals prepared from a poly(ethylene) glycol Modified UrethaneAcrylite(PMUA) precursor was applied to enhance the bioavailability of PolynuclearAromatic Hydrocarbons(PAHs) in soil and aqueous solutions. Due to the hydrophobicity of interior regions of PMUA there is increased affinitybetween PAHs and released into the aqueous phase and enhances the rate ofMineralization.Subsequently the released PAHs can be treated by natural attenuation orpump and treat process in which polymeric nanoparticals can be recovered and recycledafter microbial degradation of PAHs.IMMOBILIZATION OF MICROBIAL CELLS USINGNANOPARTICLESImmobilized microbial cells are frequently used in bioconversions, biotransformation,and biosynthesis processes due to their better operational stability, easier separation fromproducts for possible reuse, and satisfactory efficiency in catalysis compared to freecells. • Further nanoparticles can also be used to immobilize bacterial cells which are capable of degrading specific toxic compounds or to biorecover certain compounds. • In one of the study, • Magnetic nanoparticles (Fe3O4) were functionalized with ammonium oleate and coated on the surface of Pseudomonas delafieldii. • On application of external magnetic field to the microbial cells, the nanopartical coated cells concentrate on particular site of the reactor wall separating them from the whole solution and enabling recycling of the cells for the treatment of the same compound. • These coated cells were applied for the desulfurization of organic sulfur from the fossil fuel.[i.e.-dibenzothiophene] in a bioreactor and were observed to be as efficient as the non-nanoparticle coated microbial cells • Apart from this,
• Biodesulfurization (BDS) of dibenzothiophene (DBT) was carried out by Rhodococcus erythropolis IGST8 decorated with magnetic Fe3O4 nanoparticles, synthesized in-house by a chemical method, with an average size of 45–50 nm, in order to facilitate the post-reaction separation of the bacteria from the reaction mixture. • Scanning electron microscopy (SEM) showed that the magnetic nanoparticles substantially coated the surfaces of the bacteria. It was found that the decorated cells had a 56% higher DBT desulfurization activity in basic salt medium (BSM) compared to the nondecorated cells. • We propose that this is due to permeabilization of the bacterial membrane, facilitating the entry and exit of reactant and product respectively. Model experiments with black lipid membranes (BLM) demonstrated that the nanoparticles indeed enhance membrane permeability.PHYTOREMEDIATIONPhytoremediation, so called phytotechnology, is a relatively new technology involved theplants which play a role in remediation of contaminated environment. It is a greentechnology and environmental friendly.There are several types of plants to remedy and take up contaminants from soil, surfacewater, ground water, and sediment. Phytoremediation has been used to take up heavymetals, organic compounds and toxic chemicals such as 2,4,6-trinitrotoluene (TNT),trichloroethylene, benzene, toluene, ethyl benzene, xylene, lead, mercury, arsenic andradionuclides from contaminated environment.Nano-phytoremediation for degradation and removal of TNT-contaminated soil hasobviously more effective than either nanoremediation or phytoremediation.[33,34]Regarding the time points of the complete TNT remediation and half life of TNT, thehighest removal efficiency of nano-phytoremediation was found in soil with theTNT/nZVI ratio of 1/10 (100 mg/kg initial TNT concentration) in treated potting soil byPanicum maximum.MICROBIAL PRODUCTION OF SELENIUM NANOPARTICLESUSED FOR WASTE WATER TREATMENT AND OHERAPPLICATIONSpecialized microorganisms, so called dissimilatory metal reducers, can indeed be usedto convert water soluble, toxic selenium compounds (selenite, selenate) to waterinsoluble, non-toxic elemental selenium. However, the separation of this solid producedfrom the aqueous phase is challenging due to the fact that the solid products formed are–although pure elemental selenium- of nanoparticle size. So far, this circumventedrecovery by simple (and thus cheap) gravitational settling.Here we show that the Nano particulate size and the poor settle ability of the solidproducts formed is due to an organic polymer fraction associated. We used capillaryliquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) to identify proteins associated. We could demonstrate that these proteinsstrongly associated to selenium surfaces, not only microbially produced but also by
chemical synthesis. Furthermore, we studied the influence of the organic polymersassociated on the colloidal stability of the Nano particulate suspensions by means ofelectrophoretic measurements (i.e. zeta –potential). The results gained can be directlyused to enable selenium nanoparticle recovery by cheap gravitational settling. Thisrepresents and vital way point towards the recovery of nanoparticle elemental seleniumfrom industrial "WASTE" water.These selenium nanoparticles are used to cure Selenium deficiency in several CONCLUSIONAccording to above all application of Nanobioremediation it can be definitely concludedthat, Nanoparticals, Nanotechnological instrument play efficient role in the process ofNanobioremediation. By applying the nanobioremediation to environment hazards, it canclean them Faster and Safer than other methods and technology. We can say that,Nanobioremediation Maintain all three criteria.
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