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Microbial habitats

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Microbiology
Microbiology

Microbes play an important role in bioremediation by using their enzymatic activity to destroy pollutants or transform them into less harmful forms. During their normal metabolic processes, microbes can break down toxic compounds and convert them into simpler, non-toxic molecules. Bioremediation harnesses microbes' natural degradation abilities to clean contaminated sites using biological rather than physical or chemical methods. This approach is often more cost-effective and environmentally friendly compared to excavating and disposing of polluted soils and water.

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1 of 65
Dr. Kashif Bashir MPhil (BioInformatics) PhD (Biotechnology) University of Peshawar
• These are found in just about every kind of habitat. • Microbes are incredibly diverse thriving in environmentsfrom the very cold tothe extremely hot. • Theyare also tolerant of many other conditions such aslimited water availability high salt content and lowoxygen levels. • Not every microbe cansurvive in allhabitats.
• Only one percent of microbes that live in soil have been identified. • These organisms take part in the formation of soil and are essential components of theirecosystems. • Bacteria and fungi that live in soil feed mostly on organic matter such asother plants andanimals. • Thesemicrobes are very sensitive to their localenvironment. • Factors such as the levels of carbon dioxide and oxygen the pH moisture and temperature all affect the growth of microbes in the soil.
• Microbes live in bothfresh and salt water. • Theseorganisms include microscopic plants and animals as well asbacteria fungi andviruses. • Aswith other microbes the ones that live in water are adapted to the specific conditions of their environment. • Habitats range from ocean water with an extremely high salt content to freshwater lakes orrivers.
• Microbes also live on otherorganisms. • Aswith the ones found on people these microbes can be harmful or beneficial tothe host. • Example: • Bacteria grow in nodules on the roots of pea and bean plants. Thesemicrobes convert nitrogen from the air into aform that the plants canuse. • In many waysanimals and plants have evolved ashabitats for the millions of microbes that call them home.
• Themicrobes living in extreme conditions arecalled extremophiles. • Thisliterally meansthat they love theextreme conditions of theirhabitat. • Theextremophiles are sowell adapted to theirown environment. • Somelike the ones in hot springs needextreme temperatures to grow.
Microbial habitats
• The relationship in which one organism may depend on another for its survival. Sometimes they need each other. This is called symbiosis. EXAMPLES • Photosynthetic plants and microbes provide oxygen that humans need to live. • Trees offer shelter to other plants and animals. • And many rely on other creatures as sources of food or nutrients
• Often, especiallywith microbes, one organism livesinside another —the host. • Microbial symbiosisoccursbetween two microbes.Microbes, however,form associationswith other types of organisms, including plants andanimals. • Bacteria havealong history of symbiotic relationships, andhave evolved in conjunction with their hosts.Other microbes,suchas fungi and protists, alsoform symbiotic relationships with other organisms. • HOST-usually the LARGERmember • SYMBIONT- usually the SMALLERmember
MUTUALISM:-In this type of relationship, both partners benefit E.coli synthesizes vitamin Kin theintestine in exchangethe large intestine provides nutrientsnecessary for survival of the microorganisms. Example; E.Coli COMMENSALISM:-one organism is benefited and the otheris unaffected by this type ofrelationship. They bring no benefit to the host and yet the microorganisms benefit greatly from the environment they inhabit. Example; Staphylococcus on skin
• One organism benefits at the expense of the other all pathogens are parasites. • EXAMPLE:- • Human parasites (e.g. Lice). • BACTERIAL SYMBIOSIS • Bacteria form symbiotic relationships with many organisms, including humans. • One example is the bacteria that live inside the human digestive system. • These microbes break down food and produce vitamins that humans need. In return, the bacteria benefit from the stable environment inside the intestines.
• Fungiand plants form mutually-beneficial relationshipscalled mycorrhizal associations. • Thefungi increasethe absorption of water and nutrients by the plants, and benefit from the compounds produced by the plants duringphotosynthesis. • Thefungus alsoprotects the roots from diseases.Somefungi form extensive networks beneath the ground, and havebeen known to transport nutrients between plants and trees in different locations.
• In this mutually-beneficial relationship, the fungus forms the body of the lichen —the thallus. Thisstructure attaches to the surfaceof arock ortree. • The fungal cells absorb water and nutrients from the surrounding environment. Algal cells grow inside the cells of the fungus. The algal cells convert sunlight to chemicalenergy through photosynthesis. • This process benefits the fungus. In return, the algal cells are protected from theenvironment.
Microbial habitats
Biogeochemical Cycles or Nutrient cycles: Is how elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another. Types of Biogeochemical Cycle: • Atmospheric- carbon cycle and nitrogen cycle • Sedimentary - phosphorus cycle and Sulphur cycle
• Matter canneither be created ordestroyed. • Aconstant amount of matter in the environment must be recycled. • Microbes are essential in the conversion ofnutrients into organic and usable formats. • Microbes are essential in the conversion of nutrients into the inorganic form.
Microbial habitats
Carbon is akey ingredient of living tissue. In the atmosphere, carbon is present ascarbon dioxidegas, CO2. Carbon dioxide is released into the atmosphereby volcanic activity respiration Human activities the Plants take in carbon dioxide and usethe carbon tobuild carbohydrates during photosynthesis. The carbohydrates are passed along food webs to animals and other consumers. In the ocean, carbon is alsofound, along with calciumand oxygen, in calcium carbonate, which is formed by manymarine organism decomposition of organicmatter.
Microbial habitats
Microbes decompose proteins form dead cells andrelease amino acids. Ammonia is liberated by microbial ammonification ofamino acids. Ammonia is oxidized to produce nitrates forenergy by nitrifying bacteria. Denitrifying bacteria reduce nitrogen in nitrates tomolecular nitrogen. N2 is converted into ammonia by nitrogen fixing bacteria Ammonium and nitrate are used by bacteria and plantsto synthesize amino acids.
Microbial habitats
Plants and certain microbes can useSO42-to makeamino acids. H2Sis oxidized to form SO42-.
Proteinsandwasteproducts Aminoacids Microbialdecomposition Amino acids(–SH) Microbialdissimilation H2S H2S Thiobacillus SO4 2–(for energy,byrespiration) SO4 2– Microbial & plantassimilation Aminoacids
Microbial habitats
Inorganic phosphorus is solubilized by microbialacids. Made available to plants and othermicrobes Issoluble in water Combines with calcium in calcium phosphate.
Microbial habitats
• Primary producers in most ecosystemsare photoautotroph's. • Primary producers in deep oceanandendolithic communities are chemoautotrophic bacteria. H2S SO4 2– Providesenergyfor bacteria which maybeusedto fixCO2 CO2 Sugars Providescarbonfor cellgrowthCalvinCycle
Algae, cyanobacteria, aerobic heterotrophs –CO2+H2O CH2O +O2 H2Ois asource of electrons –CH2O +O2  CO2 +H2O Aerobic respiration
H2Soxidizers CO2+H2S CH2O+S+ H2O H2Sis asource ofelectrons
Tremendous ecological importance in the C,Oand Ncycles. Evolutionary relationship to plants. Cyanobacteria have chlorophyll a, carotenoids andphycobilins .
Cyanobacteria are very similar to the chloroplasts of red algae (Rhodophyta). Severalspecies of cyanobacteria are symbionts of liverworts, ferns, cycads,flagellated protozoa, andalgae. Example: There is also an exampleof acyanobacterium as endosymbionts of plant cells.
Microbial habitats
 Intensification of agriculture and manufacturing industries has resulted in increased release of a wide range of xenobiotic compounds to the environment.  Excess loading of hazardous  waste has led to scarcity of clean water and disturbances of soil thus limiting crop production.  Environment is formed by the combination of air , soil, water in the oceans, lakes etc.  Trees play an important role in the environment.  They may pollute or clean the environment.
In bioremediation, microorganisms are used to destroyor immobilize wastematerials. Bacteria Fungi Algae Actinomycetes (filamentous bacteria)
 Useof living organisms (e.g., bacteria) to clean up oil spills or remove other pollutants fromsoil, water, and waste water.“ Source:UnitedStates Environmental Protection Agency,Officeof Compliance andAssurance “clean-up of pollution from soil, groundwater, surface water and air, using biological, usually microbiologicalprocesses” Source:Philipetal.,2001
Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. Microbes play its role by the activities of their enzymes, which helps in the destruction of pollutants or their transformation to lessharmfulforms. Microorganisms are very important in bioremediation because they have extraordinary metabolicdiversity.
• Industrial wastes • Loss of ecosystem/habitat • Overfishing-depressed fish stock • Soil erosion • Fresh water supplies • Infectious disease
1. Air pollution 2. Water pollution 3. Toxic and heavy metal pollution 4. Solid and hazardous waste
Major environmental problem in cities Sources • Vehicle emissions • Industrial plants • Power stations • Oil refinery • Domestic heating • Cement plants
Gives rise to 3 other phenomena • Acid rain • Ozone depletion • Global warming climatic change
Ozone • A bluish reactive gas made up of 3 oxygen atoms • 10-40km above the earth surface • Protects life on earth from UV light Problems ?? • Appearance of holes • Holes created by gases CFC, halons, methyl bromide • Effects excess UV skin burns, skin cancer, cataracts,
GLOBAL WARMING • World is warming • Cause emission of CO2 and other greenhouse gas • Consequence Temperature change 1.1oF (0.6oC) but the effects are quite drastic • Tree-eating wood beetles are likely to benefit from a warmer climate and reproduce in ever-increasing numbers
2. WATER POLLUTION Sources • Municipal detergents / washing powder high in phosphates • Industrial toxic wastes and organic substances • Agriculture fertilizers esp. nitrates PESTICIDES Problems with pesticides • Only 0.1 reach targets the rest - 99 affects non-target organisms widely dispersed in the environment • 10 of 80,000 pesticides used are carcinogenic e.g. testicular cancer • Highly toxic to aquatic life
AZODYES • Synthetic colorants • One of the oldest man-made chemicals • Applications in textiles, food, cosmetics, plastics, leather, paper, color photography, pharmaceutical industries AZODYES - Problems • Not easily degraded • About 10 of dyestuff does not bind to fibres during dyeing process • ? released into the environment accumulate in the biosphere • Some are carcinogenic
3. TOXIC AND HEAVY METALS POLLUTION What are heavy metals ??? • Metallic chemicals like mercury, lead, cadmium, arsenic, copper and zinc that can be harmful pollutants when they enter soil and water generally toxic in low concentrations to plants and animals persist in the environment and bioaccumulate tend to be toxic Heavy metal pollution • From extensive use in agriculture, chemical and industrial processes and waste disposal • Electronic wastes TV and computer monitors contain between 3-5 kg of lead
• Threat to human health and limit plant productivity heavy metal poisoning
BIOREMEDIATION How to remediate restore polluted environment? • Use physical and chemical methods e.g. • dig up contaminated soils remove it to landfills • capping and containment • use chemicals
BIOREMEDIATION Using living organisms to decontaminate polluted systems Living organisms 1. Bacteria 2. Fungi 3. Algae
BIOREMEDIATION • Why bacteria ? • most common bioremediation microorganisms • Natures recyclers e.g. Carbon, Nitrogen cycle • Can degrade a variety of compounds as a result of million of years of evolution • With genetic engineering, can be tailored to degrade pollutants that we want
BIOREMEDIATION • How do bacteria degrade pollutants ??? • produce enzymes • break up toxic compounds to lesser or non-toxic compounds
BIOREMEDIATION Current research • HEAVY METALS • PESTICIDES • DYES • DETERGENTS • PLASTICS • OILS HYDROCARBONS
 Phytoremediation describesthe treatment ofenvironmental problemsthrough the useof plants that mitigate the environmentalproblemwithout the needto excavatethe contaminantmaterial anddisposeof itelsewhere.
 Rhizoremediation, which is the most evolved process of bioremediation, involves the removal of specific contaminants from contaminated sites by mutual interaction of plant roots and suitable microbialflora.
Microorganisms usetheir enzymatic activity for thedestruction of pollutants or their transformation to less harmful forms. Their enzymatic action on the contaminants of environment, break them into digestible form and there microbes get energy by performing normalmetabolism. Here augmentation alsoinvolves.
Contaminant compounds are transformed by living organisms through reactions that take place as a part of their metabolic processes. Biodegradation of a compound is often a result of the actions of multiple organisms. When microorganisms are imported to a contaminated site to enhance degradation we have a process known asbioaugmentation.
• Microbes can convert many chemicals into harmless compounds usingcleanupreaction. • Aerobic or anaerobically. • Both involve oxidation and reductionreactions. • Oxidation involves the removal of one ormore electrons. • Reduction involves the addition of one ormore electrons. • Oxidizing agents gain electrons and reducing agents loseelectron. • When both reaction occursat atime, it will be redox • reaction.
Petroleum Hydrocarbons Gasoline Diesel Fuel Polyaromatic Hydrocarbons Creosote Chlorinated Hydrocarbons Chlorinated Aliphatics: trichloroethylene Chlorinated Aromatics : PCB’s, Pentachlorophenol Explosives RDX, TNT Inorganic via Reduction to a Lower Valence Causing Precipitation Uranium, Technicium Sulfur and Sulfuric Acid Ammonia or Nitrate/Nitrite
Primary substrate enough available to be the sole energysource Secondary substrate provides energy, not available in highenough concentration Co metabolicsubstrate fortuitous transformation of acompound by amicrobe relying on some other primarysubstrate
EDTA is achemical agent which reduces the toxicity produced by the contaminants in the environment specially inwater. ForExample, if the toxicity results from heavy metals, EDTAwill be added to the waste and the effluent will be tested again to determine if the toxicity hasbeen acceptablyreduced.
On the basis of removal and transportation of wastes for treatment there are basically twomethods Ex-situ (off-site) strategies Excavation/pumping, followed by… Landfill Incineration Chemical removal In-situ (on-site) strategies Immobilization (chemicals, wells, membranes)
• Canbe highly specific • Lessexpensivethan excavation or incineration processes • If mineralization occursget complete degradation and cleanup • Does not transfer contaminants from one environment to another • Usesanatural process • Goodpublic acceptance • Processis simple
• Not instantaneous. • Often need to develop a system. • Always need to test and optimize conditions empirically – not with computer models. • May have inhibitors present. • Compounds may not be in a biodegradable form – polymers, plastics.
• We should clean the environment including land ,soil, water etc. by using biological methods in which bioremediation is very suitable. • In bioremediation, microbes play important role by their enzymatic activity. • They do normal metabolism and destroy the pollutants. • We can purify the wastewater, polluted soil, do better crop production, better variety of fruits. • In this way it is economically important method.
Bioremediation is an attractive alternative to traditional physico-chemical techniques for remediation of contaminated sites • Cost effective • Selectively degrade pollutants without damaging site indigenous flora and fauna • Low-technology techniques • High public acceptance
BUT STILL FRAUGHT WITH PROBLEMS • Substrate and environmental variability • Limited biodegradative potential and variability of naturally occurring microorganisms • HOWEVER may be overcome by biomolecular engineering enhance bioremediation programs

More Related Content

Microbial habitats

  • 1. Dr. Kashif Bashir MPhil (BioInformatics) PhD (Biotechnology) University of Peshawar
  • 2. • These are found in just about every kind of habitat. • Microbes are incredibly diverse thriving in environmentsfrom the very cold tothe extremely hot. • Theyare also tolerant of many other conditions such aslimited water availability high salt content and lowoxygen levels. • Not every microbe cansurvive in allhabitats.
  • 3. • Only one percent of microbes that live in soil have been identified. • These organisms take part in the formation of soil and are essential components of theirecosystems. • Bacteria and fungi that live in soil feed mostly on organic matter such asother plants andanimals. • Thesemicrobes are very sensitive to their localenvironment. • Factors such as the levels of carbon dioxide and oxygen the pH moisture and temperature all affect the growth of microbes in the soil.
  • 4. • Microbes live in bothfresh and salt water. • Theseorganisms include microscopic plants and animals as well asbacteria fungi andviruses. • Aswith other microbes the ones that live in water are adapted to the specific conditions of their environment. • Habitats range from ocean water with an extremely high salt content to freshwater lakes orrivers.
  • 5. • Microbes also live on otherorganisms. • Aswith the ones found on people these microbes can be harmful or beneficial tothe host. • Example: • Bacteria grow in nodules on the roots of pea and bean plants. Thesemicrobes convert nitrogen from the air into aform that the plants canuse. • In many waysanimals and plants have evolved ashabitats for the millions of microbes that call them home.
  • 6. • Themicrobes living in extreme conditions arecalled extremophiles. • Thisliterally meansthat they love theextreme conditions of theirhabitat. • Theextremophiles are sowell adapted to theirown environment. • Somelike the ones in hot springs needextreme temperatures to grow.
  • 8. • The relationship in which one organism may depend on another for its survival. Sometimes they need each other. This is called symbiosis. EXAMPLES • Photosynthetic plants and microbes provide oxygen that humans need to live. • Trees offer shelter to other plants and animals. • And many rely on other creatures as sources of food or nutrients
  • 9. • Often, especiallywith microbes, one organism livesinside another —the host. • Microbial symbiosisoccursbetween two microbes.Microbes, however,form associationswith other types of organisms, including plants andanimals. • Bacteria havealong history of symbiotic relationships, andhave evolved in conjunction with their hosts.Other microbes,suchas fungi and protists, alsoform symbiotic relationships with other organisms. • HOST-usually the LARGERmember • SYMBIONT- usually the SMALLERmember
  • 10. MUTUALISM:-In this type of relationship, both partners benefit E.coli synthesizes vitamin Kin theintestine in exchangethe large intestine provides nutrientsnecessary for survival of the microorganisms. Example; E.Coli COMMENSALISM:-one organism is benefited and the otheris unaffected by this type ofrelationship. They bring no benefit to the host and yet the microorganisms benefit greatly from the environment they inhabit. Example; Staphylococcus on skin
  • 11. • One organism benefits at the expense of the other all pathogens are parasites. • EXAMPLE:- • Human parasites (e.g. Lice). • BACTERIAL SYMBIOSIS • Bacteria form symbiotic relationships with many organisms, including humans. • One example is the bacteria that live inside the human digestive system. • These microbes break down food and produce vitamins that humans need. In return, the bacteria benefit from the stable environment inside the intestines.
  • 12. • Fungiand plants form mutually-beneficial relationshipscalled mycorrhizal associations. • Thefungi increasethe absorption of water and nutrients by the plants, and benefit from the compounds produced by the plants duringphotosynthesis. • Thefungus alsoprotects the roots from diseases.Somefungi form extensive networks beneath the ground, and havebeen known to transport nutrients between plants and trees in different locations.
  • 13. • In this mutually-beneficial relationship, the fungus forms the body of the lichen —the thallus. Thisstructure attaches to the surfaceof arock ortree. • The fungal cells absorb water and nutrients from the surrounding environment. Algal cells grow inside the cells of the fungus. The algal cells convert sunlight to chemicalenergy through photosynthesis. • This process benefits the fungus. In return, the algal cells are protected from theenvironment.
  • 15. Biogeochemical Cycles or Nutrient cycles: Is how elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another. Types of Biogeochemical Cycle: • Atmospheric- carbon cycle and nitrogen cycle • Sedimentary - phosphorus cycle and Sulphur cycle
  • 16. • Matter canneither be created ordestroyed. • Aconstant amount of matter in the environment must be recycled. • Microbes are essential in the conversion ofnutrients into organic and usable formats. • Microbes are essential in the conversion of nutrients into the inorganic form.
  • 18. Carbon is akey ingredient of living tissue. In the atmosphere, carbon is present ascarbon dioxidegas, CO2. Carbon dioxide is released into the atmosphereby volcanic activity respiration Human activities the Plants take in carbon dioxide and usethe carbon tobuild carbohydrates during photosynthesis. The carbohydrates are passed along food webs to animals and other consumers. In the ocean, carbon is alsofound, along with calciumand oxygen, in calcium carbonate, which is formed by manymarine organism decomposition of organicmatter.
  • 20. Microbes decompose proteins form dead cells andrelease amino acids. Ammonia is liberated by microbial ammonification ofamino acids. Ammonia is oxidized to produce nitrates forenergy by nitrifying bacteria. Denitrifying bacteria reduce nitrogen in nitrates tomolecular nitrogen. N2 is converted into ammonia by nitrogen fixing bacteria Ammonium and nitrate are used by bacteria and plantsto synthesize amino acids.
  • 22. Plants and certain microbes can useSO42-to makeamino acids. H2Sis oxidized to form SO42-.
  • 23. Proteinsandwasteproducts Aminoacids Microbialdecomposition Amino acids(–SH) Microbialdissimilation H2S H2S Thiobacillus SO4 2–(for energy,byrespiration) SO4 2– Microbial & plantassimilation Aminoacids
  • 25. Inorganic phosphorus is solubilized by microbialacids. Made available to plants and othermicrobes Issoluble in water Combines with calcium in calcium phosphate.
  • 27. • Primary producers in most ecosystemsare photoautotroph's. • Primary producers in deep oceanandendolithic communities are chemoautotrophic bacteria. H2S SO4 2– Providesenergyfor bacteria which maybeusedto fixCO2 CO2 Sugars Providescarbonfor cellgrowthCalvinCycle
  • 28. Algae, cyanobacteria, aerobic heterotrophs –CO2+H2O CH2O +O2 H2Ois asource of electrons –CH2O +O2  CO2 +H2O Aerobic respiration
  • 30. Tremendous ecological importance in the C,Oand Ncycles. Evolutionary relationship to plants. Cyanobacteria have chlorophyll a, carotenoids andphycobilins .
  • 31. Cyanobacteria are very similar to the chloroplasts of red algae (Rhodophyta). Severalspecies of cyanobacteria are symbionts of liverworts, ferns, cycads,flagellated protozoa, andalgae. Example: There is also an exampleof acyanobacterium as endosymbionts of plant cells.
  • 33.  Intensification of agriculture and manufacturing industries has resulted in increased release of a wide range of xenobiotic compounds to the environment.  Excess loading of hazardous  waste has led to scarcity of clean water and disturbances of soil thus limiting crop production.  Environment is formed by the combination of air , soil, water in the oceans, lakes etc.  Trees play an important role in the environment.  They may pollute or clean the environment.
  • 34. In bioremediation, microorganisms are used to destroyor immobilize wastematerials. Bacteria Fungi Algae Actinomycetes (filamentous bacteria)
  • 35.  Useof living organisms (e.g., bacteria) to clean up oil spills or remove other pollutants fromsoil, water, and waste water.“ Source:UnitedStates Environmental Protection Agency,Officeof Compliance andAssurance “clean-up of pollution from soil, groundwater, surface water and air, using biological, usually microbiologicalprocesses” Source:Philipetal.,2001
  • 36. Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. Microbes play its role by the activities of their enzymes, which helps in the destruction of pollutants or their transformation to lessharmfulforms. Microorganisms are very important in bioremediation because they have extraordinary metabolicdiversity.
  • 37. • Industrial wastes • Loss of ecosystem/habitat • Overfishing-depressed fish stock • Soil erosion • Fresh water supplies • Infectious disease
  • 38. 1. Air pollution 2. Water pollution 3. Toxic and heavy metal pollution 4. Solid and hazardous waste
  • 39. Major environmental problem in cities Sources • Vehicle emissions • Industrial plants • Power stations • Oil refinery • Domestic heating • Cement plants
  • 40. Gives rise to 3 other phenomena • Acid rain • Ozone depletion • Global warming climatic change
  • 41. Ozone • A bluish reactive gas made up of 3 oxygen atoms • 10-40km above the earth surface • Protects life on earth from UV light Problems ?? • Appearance of holes • Holes created by gases CFC, halons, methyl bromide • Effects excess UV skin burns, skin cancer, cataracts,
  • 42. GLOBAL WARMING • World is warming • Cause emission of CO2 and other greenhouse gas • Consequence Temperature change 1.1oF (0.6oC) but the effects are quite drastic • Tree-eating wood beetles are likely to benefit from a warmer climate and reproduce in ever-increasing numbers
  • 43. 2. WATER POLLUTION Sources • Municipal detergents / washing powder high in phosphates • Industrial toxic wastes and organic substances • Agriculture fertilizers esp. nitrates PESTICIDES Problems with pesticides • Only 0.1 reach targets the rest - 99 affects non-target organisms widely dispersed in the environment • 10 of 80,000 pesticides used are carcinogenic e.g. testicular cancer • Highly toxic to aquatic life
  • 44. AZODYES • Synthetic colorants • One of the oldest man-made chemicals • Applications in textiles, food, cosmetics, plastics, leather, paper, color photography, pharmaceutical industries AZODYES - Problems • Not easily degraded • About 10 of dyestuff does not bind to fibres during dyeing process • ? released into the environment accumulate in the biosphere • Some are carcinogenic
  • 45. 3. TOXIC AND HEAVY METALS POLLUTION What are heavy metals ??? • Metallic chemicals like mercury, lead, cadmium, arsenic, copper and zinc that can be harmful pollutants when they enter soil and water generally toxic in low concentrations to plants and animals persist in the environment and bioaccumulate tend to be toxic Heavy metal pollution • From extensive use in agriculture, chemical and industrial processes and waste disposal • Electronic wastes TV and computer monitors contain between 3-5 kg of lead
  • 46. • Threat to human health and limit plant productivity heavy metal poisoning
  • 47. BIOREMEDIATION How to remediate restore polluted environment? • Use physical and chemical methods e.g. • dig up contaminated soils remove it to landfills • capping and containment • use chemicals
  • 48. BIOREMEDIATION Using living organisms to decontaminate polluted systems Living organisms 1. Bacteria 2. Fungi 3. Algae
  • 49. BIOREMEDIATION • Why bacteria ? • most common bioremediation microorganisms • Natures recyclers e.g. Carbon, Nitrogen cycle • Can degrade a variety of compounds as a result of million of years of evolution • With genetic engineering, can be tailored to degrade pollutants that we want
  • 50. BIOREMEDIATION • How do bacteria degrade pollutants ??? • produce enzymes • break up toxic compounds to lesser or non-toxic compounds
  • 51. BIOREMEDIATION Current research • HEAVY METALS • PESTICIDES • DYES • DETERGENTS • PLASTICS • OILS HYDROCARBONS
  • 52.  Phytoremediation describesthe treatment ofenvironmental problemsthrough the useof plants that mitigate the environmentalproblemwithout the needto excavatethe contaminantmaterial anddisposeof itelsewhere.
  • 53.  Rhizoremediation, which is the most evolved process of bioremediation, involves the removal of specific contaminants from contaminated sites by mutual interaction of plant roots and suitable microbialflora.
  • 54. Microorganisms usetheir enzymatic activity for thedestruction of pollutants or their transformation to less harmful forms. Their enzymatic action on the contaminants of environment, break them into digestible form and there microbes get energy by performing normalmetabolism. Here augmentation alsoinvolves.
  • 55. Contaminant compounds are transformed by living organisms through reactions that take place as a part of their metabolic processes. Biodegradation of a compound is often a result of the actions of multiple organisms. When microorganisms are imported to a contaminated site to enhance degradation we have a process known asbioaugmentation.
  • 56. • Microbes can convert many chemicals into harmless compounds usingcleanupreaction. • Aerobic or anaerobically. • Both involve oxidation and reductionreactions. • Oxidation involves the removal of one ormore electrons. • Reduction involves the addition of one ormore electrons. • Oxidizing agents gain electrons and reducing agents loseelectron. • When both reaction occursat atime, it will be redox • reaction.
  • 57. Petroleum Hydrocarbons Gasoline Diesel Fuel Polyaromatic Hydrocarbons Creosote Chlorinated Hydrocarbons Chlorinated Aliphatics: trichloroethylene Chlorinated Aromatics : PCB’s, Pentachlorophenol Explosives RDX, TNT Inorganic via Reduction to a Lower Valence Causing Precipitation Uranium, Technicium Sulfur and Sulfuric Acid Ammonia or Nitrate/Nitrite
  • 58. Primary substrate enough available to be the sole energysource Secondary substrate provides energy, not available in highenough concentration Co metabolicsubstrate fortuitous transformation of acompound by amicrobe relying on some other primarysubstrate
  • 59. EDTA is achemical agent which reduces the toxicity produced by the contaminants in the environment specially inwater. ForExample, if the toxicity results from heavy metals, EDTAwill be added to the waste and the effluent will be tested again to determine if the toxicity hasbeen acceptablyreduced.
  • 60. On the basis of removal and transportation of wastes for treatment there are basically twomethods Ex-situ (off-site) strategies Excavation/pumping, followed by… Landfill Incineration Chemical removal In-situ (on-site) strategies Immobilization (chemicals, wells, membranes)
  • 61. • Canbe highly specific • Lessexpensivethan excavation or incineration processes • If mineralization occursget complete degradation and cleanup • Does not transfer contaminants from one environment to another • Usesanatural process • Goodpublic acceptance • Processis simple
  • 62. • Not instantaneous. • Often need to develop a system. • Always need to test and optimize conditions empirically – not with computer models. • May have inhibitors present. • Compounds may not be in a biodegradable form – polymers, plastics.
  • 63. • We should clean the environment including land ,soil, water etc. by using biological methods in which bioremediation is very suitable. • In bioremediation, microbes play important role by their enzymatic activity. • They do normal metabolism and destroy the pollutants. • We can purify the wastewater, polluted soil, do better crop production, better variety of fruits. • In this way it is economically important method.
  • 64. Bioremediation is an attractive alternative to traditional physico-chemical techniques for remediation of contaminated sites • Cost effective • Selectively degrade pollutants without damaging site indigenous flora and fauna • Low-technology techniques • High public acceptance
  • 65. BUT STILL FRAUGHT WITH PROBLEMS • Substrate and environmental variability • Limited biodegradative potential and variability of naturally occurring microorganisms • HOWEVER may be overcome by biomolecular engineering enhance bioremediation programs

Editor's Notes

  1. Cataract: Clouding of eye