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Showing posts with label AGRICULTURE. Show all posts
Showing posts with label AGRICULTURE. Show all posts
Wednesday, November 12, 2008
Monday, November 3, 2008
BACTERIAL CLASSIFICATION
• HOW DO VIRUSES REPRODUCE & CAUSE DISEASE?
• VIRAL LIFECYCLES
• VIRAL DNA MAY BECOME PART OF HOST CHROMOSOME
• Viruses are packaged genes-can only reproduce inside cells.
• Lytic cycle-viral replication cycle resulting in the release of new viruses by lysis of host cell.
• Lysogenic cycle-a bacteriophage replication cycle in which the viral genome is incorporated into the bacterial host chromosome and the host cell is not lysed unless the viral genome leaves the host chromosome.
• MANY VIRUSES CAUSE DISEASE IN ANIMALS
• Viruses that infect animal cells cause diseases.
• RNA viruses have RNA as their genetic material and responsible for flu, cold, measles, mumps, AIDS, polio.
• DNA viruses have DNA as their genetic material and cause hepatitis, chicken pox, herpes.
• Amount of damage a virus can cause depends on: how quickly our immune system responds to fight the infection and ability of the infected tissue to repair itself.
• Recover quickly from colds since respiratory tract can efficiently replace damaged cells by mitosis.
• Poliovirus attacks cause permanent damage since nerve cells don’t divide. Prevention = vaccines.
• Antibiotics for bacterial infections are futile for curing viral infections.
• Development of antiviral drugs is slow since it’s difficult to find ways to kill a virus and not its host cell.
• HIV MODEL
• AIDS VIRUS MAKES DNA ON AN RNA TEMPLATE (RETROVIRUS)
• AIDS caused by a type of RNA virus.
• HIV virus is aided by membranous envelope and glycoprotein spikes to enter and leave a host cell.
• HIV contains 2 copies of RNA instead of 1.
• HIV is a retrovirus as it synthesizes
– DNA on an RNA template by
– the help of an enzyme,
– reverse transcriptase
– (catalyzes reverse transcription).
• BEHAVIOUR OF HIV NUCLEIC ACID IN A HOST CELL
• HIV RNA uncoated in the cytoplasm of host cell.
• Reverse transcriptase uses RNA as template to make DNA strand.
• Then adds second complementary DNA strand.
• Double stranded DNA enters cell’s nucleus and inserts itself into chromosomal DNA = provirus.
• Provirus is transcribed into RNA and translated into viral proteins.
• New viruses leave the cell and infect other cells.
• DO YOU UNDERSTAND BASIC BACTERIAL NUTRITION?
• PROKARYOTES COME IN VARIETY OF SHAPE
• PROKARYOTES COME IN VARIETY OF SHAPE
• Cocci-spherical, occur in clusters, are called staphylococci. Those in chains-streptococci.
• Bacilli-rod-shaped, most occur singly but in pairs (diplobacilli) and in chains (streptobacilli).
• Curved or spiral.
• Commas called vibrios.
• Helical.
• Relatively short = spirilla.
• Longer, more flexible = spirochete.
• PROKARYOTES OBTAIN NOURISHMENT IN A VARIETY OF WAYS
• 2 main resources: carbon (for synthesizing organic compounds) and energy.
• Prokaryotes exhibit much more nutritional diversity than eukaryotes.
• THE EARLY EVOLUTION OF NUTRITION
• Chemoheterotrophs dominant prokaryotes today and may have been since dawn of life.
• First prokaryote may have had simple metabolism requiring only few enzymes.
• Its environment contained no oxygen, metabolism anaerobic.
• Unlikely that sunlight was used as energy source since complex set of enzymes needed for such use.
• Carbon and energy obtained from rich soup of molecules and ions in which they evolved.
• ARCHAEA THRIVE IN EXTREME ENVIRONMENT & IN OCEAN
• Archaeal inhabitants of extreme environments have unusual proteins and other molecular adaptations that enable effective metabolism and reproduction.
• Archaea are extremophiles-can thrive in extreme environments (too hot, too salty, too acidic for other organisms).
• Extreme halophiles
• Thrive in very salty places.
• Extreme thermophiles
• Thrive in very hot water.
• In deep-ocean vents where water 1000C.
• HOW DO BACTERIA EXPLOIT SO MANY HABITATS?
HOW ARE BACTERIA A CAUSE OF DISEASE?
• DIVERSE STRUCTURAL FEATURES AID PROKARYOTES THRIVE ALMOST EVERYWHERE
Flagella
• Enables moving towards favourable places and away from less favourable ones.
• Prokaryotic flagellum is naked protein structure that lacks microtubules unlike flagellum of eukaryotic cell.
• Rings give flagellum propeller-like rotary movement.
• PILI
• Shorter and thinner than flagella.
• Help bacteria to stick to each other and to surfaces such as rocks in streams, human intestine lining, etc.
• Sex pili required for initiating bacterial “mating”.
• ENDOSPORES
• Bacteria can survive extended periods of harsh conditions by forming specialized “resting cells”.
• Has thick, protective coat, its cytoplasm is dehydrated and it does not metabolize.
• Under harsh conditions, outer cell disintegrates but endospore survives all sorts of trauma.
• When environment favourable, endospore absorbs water and resumes growth.
• Not even boiling water can kill these.
• CYANOBACTERIA
• Blue-green colour caused by trillions of cyanobacterial cells.
• Photosynthetic bacteria.
• Common in lakes, ponds, tropical oceans.
• Extensive blooms indicate polluted water conditions usually phosphates and nitrates from agricultural run offs.
• About 3.0 to 1.5bya, ancient cyanobacteria gave earth its first greenish coat.
• SOME BACTERIA CAUSE DISEASES
• Pathogens-disease causing agents.
• Most cause disease by producing poisons, two types:
• Exotoxin-toxic proteins secreted by bacterial cells, include most of the potent poisons.
• Endotoxins-not cell secretions, but components of the cell walls of certain bacteria.
• WHY ARE BACTERIA VITAL TO THE ENVIRONMENT?
• BACTERIA CAN BE USED AS BIOLOGICAL WEAPONS-BIOTERRORISM
• Animals, plants, fungi, bacteria and viruses.
• To weaponize naturally occurring pathogens, researchers selected highly virulent strains, made them antibiotic resistant and developed formulations for effective dispersion.
• Bacillus anthracis-bioweapon since it’s easier to obtain (bacterium lives in soils in agricultural regions), easy to grow in labs and forms hardy endospores that can be stored for years.
• In bloodstream, anthrax bacteria actively metabolize and multiply-release 3 proteins that combine to form toxin that destroys body tissues and cells of the immune system.
• PROKARYOTES HELP RECYCLE CHEMICALS AND CLEAN UP ENVIRONMENT
• Restores oxygen to atmosphere.
• Some cyanobacteria convert nitrogen gas in atm to nitrogen (N) cpds (nitrates and nitrites) that plants take up and use.
• Other prokaryotes living in nodules on roots of legumes contribute large amounts of N cpds to soil.
• Decomposition of organic wastes and dead organisms to inorganic chemicals that other organisms can use.
• Prokaryote decomposers are also mainstays of our sewage treatment facilities.
• Aid in bioremediation-use of prokaryotes (or other organisms) to clean up pollution.
• VIRAL LIFECYCLES
• VIRAL DNA MAY BECOME PART OF HOST CHROMOSOME
• Viruses are packaged genes-can only reproduce inside cells.
• Lytic cycle-viral replication cycle resulting in the release of new viruses by lysis of host cell.
• Lysogenic cycle-a bacteriophage replication cycle in which the viral genome is incorporated into the bacterial host chromosome and the host cell is not lysed unless the viral genome leaves the host chromosome.
• MANY VIRUSES CAUSE DISEASE IN ANIMALS
• Viruses that infect animal cells cause diseases.
• RNA viruses have RNA as their genetic material and responsible for flu, cold, measles, mumps, AIDS, polio.
• DNA viruses have DNA as their genetic material and cause hepatitis, chicken pox, herpes.
• Amount of damage a virus can cause depends on: how quickly our immune system responds to fight the infection and ability of the infected tissue to repair itself.
• Recover quickly from colds since respiratory tract can efficiently replace damaged cells by mitosis.
• Poliovirus attacks cause permanent damage since nerve cells don’t divide. Prevention = vaccines.
• Antibiotics for bacterial infections are futile for curing viral infections.
• Development of antiviral drugs is slow since it’s difficult to find ways to kill a virus and not its host cell.
• HIV MODEL
• AIDS VIRUS MAKES DNA ON AN RNA TEMPLATE (RETROVIRUS)
• AIDS caused by a type of RNA virus.
• HIV virus is aided by membranous envelope and glycoprotein spikes to enter and leave a host cell.
• HIV contains 2 copies of RNA instead of 1.
• HIV is a retrovirus as it synthesizes
– DNA on an RNA template by
– the help of an enzyme,
– reverse transcriptase
– (catalyzes reverse transcription).
• BEHAVIOUR OF HIV NUCLEIC ACID IN A HOST CELL
• HIV RNA uncoated in the cytoplasm of host cell.
• Reverse transcriptase uses RNA as template to make DNA strand.
• Then adds second complementary DNA strand.
• Double stranded DNA enters cell’s nucleus and inserts itself into chromosomal DNA = provirus.
• Provirus is transcribed into RNA and translated into viral proteins.
• New viruses leave the cell and infect other cells.
• DO YOU UNDERSTAND BASIC BACTERIAL NUTRITION?
• PROKARYOTES COME IN VARIETY OF SHAPE
• PROKARYOTES COME IN VARIETY OF SHAPE
• Cocci-spherical, occur in clusters, are called staphylococci. Those in chains-streptococci.
• Bacilli-rod-shaped, most occur singly but in pairs (diplobacilli) and in chains (streptobacilli).
• Curved or spiral.
• Commas called vibrios.
• Helical.
• Relatively short = spirilla.
• Longer, more flexible = spirochete.
• PROKARYOTES OBTAIN NOURISHMENT IN A VARIETY OF WAYS
• 2 main resources: carbon (for synthesizing organic compounds) and energy.
• Prokaryotes exhibit much more nutritional diversity than eukaryotes.
• THE EARLY EVOLUTION OF NUTRITION
• Chemoheterotrophs dominant prokaryotes today and may have been since dawn of life.
• First prokaryote may have had simple metabolism requiring only few enzymes.
• Its environment contained no oxygen, metabolism anaerobic.
• Unlikely that sunlight was used as energy source since complex set of enzymes needed for such use.
• Carbon and energy obtained from rich soup of molecules and ions in which they evolved.
• ARCHAEA THRIVE IN EXTREME ENVIRONMENT & IN OCEAN
• Archaeal inhabitants of extreme environments have unusual proteins and other molecular adaptations that enable effective metabolism and reproduction.
• Archaea are extremophiles-can thrive in extreme environments (too hot, too salty, too acidic for other organisms).
• Extreme halophiles
• Thrive in very salty places.
• Extreme thermophiles
• Thrive in very hot water.
• In deep-ocean vents where water 1000C.
• HOW DO BACTERIA EXPLOIT SO MANY HABITATS?
HOW ARE BACTERIA A CAUSE OF DISEASE?
• DIVERSE STRUCTURAL FEATURES AID PROKARYOTES THRIVE ALMOST EVERYWHERE
Flagella
• Enables moving towards favourable places and away from less favourable ones.
• Prokaryotic flagellum is naked protein structure that lacks microtubules unlike flagellum of eukaryotic cell.
• Rings give flagellum propeller-like rotary movement.
• PILI
• Shorter and thinner than flagella.
• Help bacteria to stick to each other and to surfaces such as rocks in streams, human intestine lining, etc.
• Sex pili required for initiating bacterial “mating”.
• ENDOSPORES
• Bacteria can survive extended periods of harsh conditions by forming specialized “resting cells”.
• Has thick, protective coat, its cytoplasm is dehydrated and it does not metabolize.
• Under harsh conditions, outer cell disintegrates but endospore survives all sorts of trauma.
• When environment favourable, endospore absorbs water and resumes growth.
• Not even boiling water can kill these.
• CYANOBACTERIA
• Blue-green colour caused by trillions of cyanobacterial cells.
• Photosynthetic bacteria.
• Common in lakes, ponds, tropical oceans.
• Extensive blooms indicate polluted water conditions usually phosphates and nitrates from agricultural run offs.
• About 3.0 to 1.5bya, ancient cyanobacteria gave earth its first greenish coat.
• SOME BACTERIA CAUSE DISEASES
• Pathogens-disease causing agents.
• Most cause disease by producing poisons, two types:
• Exotoxin-toxic proteins secreted by bacterial cells, include most of the potent poisons.
• Endotoxins-not cell secretions, but components of the cell walls of certain bacteria.
• WHY ARE BACTERIA VITAL TO THE ENVIRONMENT?
• BACTERIA CAN BE USED AS BIOLOGICAL WEAPONS-BIOTERRORISM
• Animals, plants, fungi, bacteria and viruses.
• To weaponize naturally occurring pathogens, researchers selected highly virulent strains, made them antibiotic resistant and developed formulations for effective dispersion.
• Bacillus anthracis-bioweapon since it’s easier to obtain (bacterium lives in soils in agricultural regions), easy to grow in labs and forms hardy endospores that can be stored for years.
• In bloodstream, anthrax bacteria actively metabolize and multiply-release 3 proteins that combine to form toxin that destroys body tissues and cells of the immune system.
• PROKARYOTES HELP RECYCLE CHEMICALS AND CLEAN UP ENVIRONMENT
• Restores oxygen to atmosphere.
• Some cyanobacteria convert nitrogen gas in atm to nitrogen (N) cpds (nitrates and nitrites) that plants take up and use.
• Other prokaryotes living in nodules on roots of legumes contribute large amounts of N cpds to soil.
• Decomposition of organic wastes and dead organisms to inorganic chemicals that other organisms can use.
• Prokaryote decomposers are also mainstays of our sewage treatment facilities.
• Aid in bioremediation-use of prokaryotes (or other organisms) to clean up pollution.
Friday, October 31, 2008
BIOREMEDIATION
Bioremediation is the use of biological processes to remove contaminants from the environment
Decontamination through biological agents such as microbes, plants and fungi usually occurs naturally in the environment but is often slow
Bioremediation uses naturally occurring bacteria and fungi or plants to degrade or detoxify substances hazardous to human health and/or the environment
There are 2 Types of Microorganisms
Biostimulation
Bioaugmentation
How does bioremediation work?
The majority of bioremediation involves a redox reaction that detoxifies the contaminant
However the reaction can be expedited by improving the environmental conditions in one of the following ways depending on what the limiting factor is
These factors are,
Cont..
Limiting factors
Adding an electron acceptor
Adding an electron donor
Adding a limiting nutrient
Increasing the bioavailability of the contaminant.
Stimulating the production of a specific enzyme
Major Types of Bioremediation
1.In situ Bioremediation
In situ treatment means that remediation occurs directly at the site of the contaminant
2.Ex situ Bioremediation
Ex situ treatment requires that the contaminant be transported elsewhere
Cont….
Ex-situ -Bioremediation
Slurry-phase
Soil combined with
water/additives in tank, microorganisms, nutrients,
oxygen added
Advantages of Ex-situ Bioremediation
Easier to control
Used to treat wider range of contaminants and soil types
Faster
In-situ Bioremediation
Biostimulation - stimulates biological activity.
Bioventing (Inject air/nutrients into unsaturated zone – good for midweight petroleum, jet fuel)
Biosparging (Inject air/nutrients into unsaturated and saturated zones)
Bioaugmentation - Inoculates soil with microbes.
Advantages of In-situ Bioremediation
Less expensive
Creates less dust
Less possibility of contaminant release into environment
Good for large volumes
Ex-situ treatment
Is the better understood and developed approach to bioremediation, though recently in-situ is gaining much attention.
In-situ treatment
Is usually more advantageous than
Ex-situ since it requires less equipment and labor and has a lower cost and environmental impact.
How Contamination Occurs
Oil Leaks from Ships
Use of Agricultural Chemicals
Industrial Wastes
Domestic Wastes
Laboratory Wastes
Contamination Transport
Spills or leaks sink into soil or water
Get transported by water movement
Classes of contaminants biodegraded
Natural Bioremediation
Natural strains have biodegradative capability
Can use In-situ populations
Need to increase total population by adding substrates
Contaminated sites often very low nutrient
Contain mixed populations of bacteria
Bioremediation Strategies
(Role of Bacteria)
Increase substrates detoxified
Ralstonia metallidurans
Deinococcus radiodurans
Increase rate of detoxification
Increase access to hydrophobic contaminants
Toxin Digesting Reactions
Denitrification 2NO3− + 10e− + 12H+ → N2 + 6H2O
Manganese MnO2 + 2e− + 4H+ → Mn2+ + 2H2O
Iron III reduction Fe(OH)3 + e− + 3H+ → Fe2+ + 3H2O
Sulfate reduction SO42− + 8e− +10 H+ → H2S + 4H2O
Fermentation 2CH2O → CO2 + CH4
Composting
The high temperatures prevalent during composting, combined with the high nutrient contents of decomposing organic matter such as manure, and the heavy microbial load of the compost system efficiently stimulate the biodegradation of hydrocarbon contamination
Surfactants
Extractions can be performed on the contaminated soil by adding surfactants in order to leach the hydrocarbons from the soil matrices
Rhizosphere Effects
The rhizosphere soil has a greater degradation capability for contaminants than does soil without plant roots.
How Bacteria Access Contaminants
Conditions that favor Bioremediation
Temperature
Water
Nutrients
C:N ratio
Oxygen in sufficient quantity
Uses of Bioremediation
Oil spill
Soil Pollution
Agricultural practices
The biggest spill ever occurred during the 1991 Persian Gulf war when about 240 million gallons spilled from oil terminals and tankers off the coast of Saudi Arabia.
Bioremediation of the Exxon Valdez Alaskan oil spill
Exxon Valdez supertanker ran aground in 1989 resulting in the spillage of about 11 million gallons of crude oil in Alaska.
How Bioremediation uses in Oil Spill.
The biodegradation by indigenous microorganisms can population could rapidly biodegrade the aliphatic and aromatic fractions of crude oil
The microbial community completely mineralized them to CO2 and H2O
Soil Bioremediation
The introduction of substances or biological organisms into the soil, resulting in a change of the soil quality, which is likely to affect the normal use of the soil or endangering public health and the living environment
Agricultural Chemicals
Fertilizer Pesticides
Weedcides
Advantages of bioremediation
Natural process and therefore perceived as an acceptable waste treatment process for contaminated soil
Many compounds can be transformed to harmless products
Complete destruction of target pollutants is possible.
Disadvantages of bioremediation
Limited to those compounds that are biodegradable
Sometimes the products of biodegradation are more toxic or persistent than the parent compounds
Biological process are highly specific
Decontamination through biological agents such as microbes, plants and fungi usually occurs naturally in the environment but is often slow
Bioremediation uses naturally occurring bacteria and fungi or plants to degrade or detoxify substances hazardous to human health and/or the environment
There are 2 Types of Microorganisms
Biostimulation
Bioaugmentation
How does bioremediation work?
The majority of bioremediation involves a redox reaction that detoxifies the contaminant
However the reaction can be expedited by improving the environmental conditions in one of the following ways depending on what the limiting factor is
These factors are,
Cont..
Limiting factors
Adding an electron acceptor
Adding an electron donor
Adding a limiting nutrient
Increasing the bioavailability of the contaminant.
Stimulating the production of a specific enzyme
Major Types of Bioremediation
1.In situ Bioremediation
In situ treatment means that remediation occurs directly at the site of the contaminant
2.Ex situ Bioremediation
Ex situ treatment requires that the contaminant be transported elsewhere
Cont….
Ex-situ -Bioremediation
Slurry-phase
Soil combined with
water/additives in tank, microorganisms, nutrients,
oxygen added
Advantages of Ex-situ Bioremediation
Easier to control
Used to treat wider range of contaminants and soil types
Faster
In-situ Bioremediation
Biostimulation - stimulates biological activity.
Bioventing (Inject air/nutrients into unsaturated zone – good for midweight petroleum, jet fuel)
Biosparging (Inject air/nutrients into unsaturated and saturated zones)
Bioaugmentation - Inoculates soil with microbes.
Advantages of In-situ Bioremediation
Less expensive
Creates less dust
Less possibility of contaminant release into environment
Good for large volumes
Ex-situ treatment
Is the better understood and developed approach to bioremediation, though recently in-situ is gaining much attention.
In-situ treatment
Is usually more advantageous than
Ex-situ since it requires less equipment and labor and has a lower cost and environmental impact.
How Contamination Occurs
Oil Leaks from Ships
Use of Agricultural Chemicals
Industrial Wastes
Domestic Wastes
Laboratory Wastes
Contamination Transport
Spills or leaks sink into soil or water
Get transported by water movement
Classes of contaminants biodegraded
Natural Bioremediation
Natural strains have biodegradative capability
Can use In-situ populations
Need to increase total population by adding substrates
Contaminated sites often very low nutrient
Contain mixed populations of bacteria
Bioremediation Strategies
(Role of Bacteria)
Increase substrates detoxified
Ralstonia metallidurans
Deinococcus radiodurans
Increase rate of detoxification
Increase access to hydrophobic contaminants
Toxin Digesting Reactions
Denitrification 2NO3− + 10e− + 12H+ → N2 + 6H2O
Manganese MnO2 + 2e− + 4H+ → Mn2+ + 2H2O
Iron III reduction Fe(OH)3 + e− + 3H+ → Fe2+ + 3H2O
Sulfate reduction SO42− + 8e− +10 H+ → H2S + 4H2O
Fermentation 2CH2O → CO2 + CH4
Composting
The high temperatures prevalent during composting, combined with the high nutrient contents of decomposing organic matter such as manure, and the heavy microbial load of the compost system efficiently stimulate the biodegradation of hydrocarbon contamination
Surfactants
Extractions can be performed on the contaminated soil by adding surfactants in order to leach the hydrocarbons from the soil matrices
Rhizosphere Effects
The rhizosphere soil has a greater degradation capability for contaminants than does soil without plant roots.
How Bacteria Access Contaminants
Conditions that favor Bioremediation
Temperature
Water
Nutrients
C:N ratio
Oxygen in sufficient quantity
Uses of Bioremediation
Oil spill
Soil Pollution
Agricultural practices
The biggest spill ever occurred during the 1991 Persian Gulf war when about 240 million gallons spilled from oil terminals and tankers off the coast of Saudi Arabia.
Bioremediation of the Exxon Valdez Alaskan oil spill
Exxon Valdez supertanker ran aground in 1989 resulting in the spillage of about 11 million gallons of crude oil in Alaska.
How Bioremediation uses in Oil Spill.
The biodegradation by indigenous microorganisms can population could rapidly biodegrade the aliphatic and aromatic fractions of crude oil
The microbial community completely mineralized them to CO2 and H2O
Soil Bioremediation
The introduction of substances or biological organisms into the soil, resulting in a change of the soil quality, which is likely to affect the normal use of the soil or endangering public health and the living environment
Agricultural Chemicals
Fertilizer Pesticides
Weedcides
Advantages of bioremediation
Natural process and therefore perceived as an acceptable waste treatment process for contaminated soil
Many compounds can be transformed to harmless products
Complete destruction of target pollutants is possible.
Disadvantages of bioremediation
Limited to those compounds that are biodegradable
Sometimes the products of biodegradation are more toxic or persistent than the parent compounds
Biological process are highly specific
BIOLOGICAL CONTROL OF PLANT DISEASES BY MICROORGANISMS
What is biological control?
Biological control can be defined as the use of natural enemies to reduce the damage caused by a pest population
• Biological control differs from "natural control
• Biological control requires intervention, rather than simply letting nature take its course
• It is an approach that fits into an overall pest management program, and represents an alternative to continued reliance on pesticides
Biological Control of diseases by microorganism
• Plant diseases are caused mainly by fungi, bacteria, viruses and nematodes
• Biocontrol of plant disease involves the use of an organism or organisms to reduce disease
Biological Control Targets
Agents that cause plant disease
Agents that cause plant damage
Weeds
What is a biological contol agent
means any living organism applied to or introduced into the environment that is intended to function as a destroying agent to control another organism ...
Biological control agents
Macroorganisms biological control agents
• Insects
• Man
• Animals
any living microorganism (Bacteria, Fungi, Nematodes & Viruses) applied to or introduced into the environment that is intended to function as a destroying to control another organism
Microbial biological control agents are
• Bacteria
• Fungi
• Nematodes
• Viruses
Bacterial Biological Control Agents
Xanthomonas campestris pv. poannua - postemergence activity on annual bluegrass in bermudagrass lawns (Johnson, 1994: Johnson, Wyse, Jones, 1996).
Pseudomonas syringae pv. tagetis - Canada thistle in soybean (Johnson, Wyse, Jones, 1996).
E.g.- Bacillus species
Bacillus spp have been widely exploited for the management of plant pathogens.
Bacillus is an ideal candidate for biocontrol of plant pathogens because of its ability to form endospores which are resting structures capable of surviving desiccation, heat, oxidising agents, UV & gamma radiations.
Many post-harvest diseases are successfully managed with Bacillus spp.
The broad spectrum activity, absence of phytoxigenic products, amenability for mass culturing, the ability to form endospores, availability of information on the genetics, physiology, r-DNA technology etc are some of the advantages of the genus Bacillus
Brown rot of potato caused by Ralstonia solanacearum is also amenable to management with Bacillus.
Bacillus spp, have been tested worldwide for management of pathogens causing spots, blights, rots etc. On the above ground parts of several plants.
Fungal Disease Control Agents
• Ampelomyces quisqualis.
• Candida oleophila.
• Coniothyrium minitans.
• Fusarium oxysporum.
• Gliocladium virens.
• Gliocladium catenulatum.
• Phlebia gigantea.
• Pythium oligandrum.
• Trichoderma harzianum and other spp.
Nematodes
There are over 300 species of nematodes that are known to attack insects.
Most of the research in biological control, however, has focused on only two genera, Steinernema and Heterorhabditis.
These nematodes are unique because they harbor symbiotic bacteria that are pathogenic to the nematode's insect host.
e.g.-nematode attacks insect pests
Nine families of nematodes (Allantone-matidae, Diplogasteridae, Heterorhabditidae, Mermithidae, Neotylenchidae, Rhabditidae, Sphaerulariidae, Steinernematidae, and Tetradonematidae) include species that attack insects and kill or sterilize them, or alter their development.
Viruses
• The use of entomopathic viruses for insect control is still in its infancy.
• Many of these pathogens appear to have good potential as bio control agents because they are relatively host-specific.
• Viral-induced mortality is usually caused by toxic proteins that accumulate during the reproductive cycle of the virus.
NPV or CPV (Nuclear or Cytoplasmic
Polyhedrosis Virus) -- Clusters of virus particles are embedded within polyhedral inclusion bodies (crystals) that develop inside the nucleus or cytoplasm of infected cells.
They usually attack larvae of Lepidoptera or Hymenoptera (sawflies).
There is also commercial interest in developing NPVs for use against corn earworms, cotton bollworms, cabbage loopers, and alfalfa butterflies.
Granulosis virus -- These pathogens typically infect the fat body in Lepidopteran larvae and pupae.
E.g.-A granulosis virus has been developed for use in apple orchards against larvae of the codling moth (Cydia pomonella).
Non-inclusion viruses -- These pathogens (entomopox virus, for example) do not produce granules or polyhedral bodies. The cause of their toxicity is not well understood, but they are usually less virulent than other types of viruses.
Biological Control Mechanisms
Competition
Antibiosis
Parasitism
Induced resistance
enzymes
Competition
The Biological control agent more efficiently utilizes space and nutrients.
Antibiosis
the Biological control agent produces one or more deleterious compounds.
Production of antibiotics seems to be the most important way in which many spp of Bacillus bring about bio control of plant pathogens.
Two antibiotics, iturin and surfactin have been B. subtilis indicated in the suppression of R. solani induced damping off of tomato by B. subtilis
Parasitism
The Biological control agent utilizes the target for food or for reproduction.
Biological control agents parasite on
• Larvae
• Eggs
• Pupa
Induced resistance
The Biological control agent indirectly stimulates the plant to be resistant.
Several beneficial rhizosphere bacteria induce systemic resistance against one or more diseases.
Increased Phenylalanine ammonia lyase (PAL) activity and increased lignification acting as barrier to the fusarial wilt pathogen in pigeon pea treated with the above bacterisl stain.
Enzymes
Mycelial lysis by enzyme production is one another mode of antagonism by many Bacillus spp.
Hydrolytic enzyme produced and released by bacteria contribute to the suppression of phytopathogens
Using Biological control agents
Advantages of Bio control
Most natural enemies used in biocontrol attack on target species & less possibility to destroy non- target organisms
Environmental friendly
• No any waste remain in the environment
Economically friendly
• Reduce cost for pesticides
Useful in Integrated pest management
BIO GAS PRODUCTION
• Biogas can be defined as a gas produced by the biological breakdown of organic matter in anaerobic conditions
• Biogas originates from organic material and is a type of biofuel
• The other method of producing biogas is wood gas which is created by gasification of wood or other biomass
• Depending on where it is produced, biogas can also be called swamp, marsh, landfill or digester gas
• Biogas contains,
• Methane -50-75%
• Carbon dioxide -25-50%
• Nitrogen -0-10%
• Hydrogen -0-1%
• Hydrogen sulfide -0-3%
• Oxygen -0-2%
• Biogas plants
• Materials used in biogas production
• The materials commonly used in biogas production are,
» Human & animal waste
» Crop residue
» Agro industrial waste
» Biomass combined with water (sewage)
» Energy crops- Maize, sunflower, wheat, grass
• Methods of biogas production
• Mainly biogas is produced using anaerobic digestion
• There are various methods & reactor types used to produce biogas
• But the production process has common steps though the methods are different
• stages of biogas production
• This natural, biological process takes place in three stages:
Hydrolysis :insoluble solids are broken down to monomers
Acidogenesis:monomers are converted to VFA
Methanogenesis:acids are converted to bio gas
• Different types of reactors
Type 1
• Influent is added to the reactor, and mixing is accomplished with gas mixers, mechanical
mixers, or recirculation pumps
• High installation and operating costs, high hydraulic retention times are required to achieve an acceptable level of degradation, signifying large reactor sizes
• Type 2
• The biomass forms sludge granules, producing a sludge bed which is completely retained in the reactor
• Allows for higher-strength wastewaters to be treated
• requires a significant amount of time, causing longer start-up times when compared to other reactors
• A diagram of type 2 reactor
• Contact Digester
• Retains biomass by separating and concentrating the solids in a separate reactor, returning these solids to the influent
• Solids separation can be achieved with gravity separators, solids thickeners, centrifuges, gravity belts, and membranes
• Sewage treatment
• Sludges from the primary and secondary treatment settling tanks are collected into an anaerobic digester
• Sludges contain cellulose, proteins, lipid and other insoluble polymers
• Anaerobic bacteria digest the sludge to methane and carbon dioxide
• Sewage treatment plant
• Using a biodigester
• Biodigester is a system that promotes decomposition of organic matter.
• It produces biogas, generated through the process of anaerobic digestion.
• Factors Affecting Biogas Production
Biogas yield is measured as
• m3 gas/kg volatile solids
• The maximum possible gas yield on complete digestion of carbohydrates (starch, cellulose, glucose) would be 0.8 m3kg.
• for fatty acids this value it is about 1.5 m3kg.
• proteins it is about 0.9 m3/kg.
This depends on,
• Type of waste
• Temperature during digester operation,
• Retention time (the period of time a given sample of waste/substrate stays in the digester/ fermenter before it flows out)
• Presence of toxic materials
• pH
• Stirring
• Carbon – Nitrogen Ratio
• Type of waste
Ex:
-Livestock & poultry wastes
-Crop residues
-Paper wastes
-Aquatic weeds
-Algae & seaweeds
• The yellow circles represents evolving biogas bubbles and the brown circles represent sludge granules. The upward liquid flow and uplifting action of gas bubbles causes the partial fluidization of the sludge bed and hydraulic mixing. The background is a scanning electron micrograph inside a sludge granule cultivated on sucrose-containing wastewater, show a diverse population of microorganisms.
• Temperature
• The choice of the temperature to be used is influenced by climatic considerations.
• Optimum process stability temperature should be carefully regulated within the a narrow range of operating temperature.
• Mesophilic fermentation at about 35°c gives the maximum gas yields,
•
• Thermophilic bacteria give best yields around 55°c.
• For sewage sludge, the gas yield at 20°c may be only 80% of that at 35°c.
• Retention time
• At high temperature bio – digestion occurs faster, reducing the time requirement.
• A normal period for the digestion of dung be two to four weeks.
• Gas yields increase with retention time since a greater proportion of the organic matter will be digested.
• Amount of OM vs retention time
• Toxic Materials
• Wastes & biodegradable residue are often accompanied by a variety of pollutants that could inhibit anaerobic digestion.
• Toxic components may include ammonia, SO42-, antibiotics, etc.
• Common toxic substances are
soluble salts of,
Copper
Zinc
Nickel
Mercury
Chromium
• Salts of
* Sodium
* Potassium
* Calcium
* Magnesium may be stimulatory or toxic in action.
• Pesticides & synthetic detergents may also be troublesome to the process.
• pH
• Low pH inhibit the growth of the methanogenic bacteria.
• A successful pH range for anaerobic digestion is 6.0 – 8.0.
• Efficient digestion occurs at a pH near neutrality.
• Low pH may be remedied by dilution or by the addition of lime.
• Carbon – Nitrogen Ratio
• The bacteria responsible for the anaerobic process require both elements
• They consume carbon roughly 30 times faster than nitrogen
• A carbon – nitrogen ratio of about 30:1 is ideal for the raw material fed into a biogas plant
• Stirring
• Stirring the slurry in a digester is always advantageous, if not essential
• If not stirred, the slurry will tend to settle out and form a hard scum on the surface, which will prevent release of the biogas
• Problem is much greater with vegetable waste than with manure, which will tend to remain in suspension
• Advantages of biogas
• provide better & cheaper fuel
• produce quality manure to improve soil fertility
• provide an effective way for sanitary disposal of human excreta
• use as a smokeless domestic fuel
• helps in generation of production employment
• Disadvantages of biogas
• Yields are lower due to the dilute nature of substrates
• The process is not very attractive economically on a large industrial scale
• New technologies cannot be used to enhance the efficiency of the process
• The process can be improved only by optimizing the environmental conditions of the anaerobic digestion
• Biogas contains some gases as impurities
• Uses of biogas
• electricity production
• Cooking
• water heating
• can replace compressed natural gas for use in vehicles
• Biogas originates from organic material and is a type of biofuel
• The other method of producing biogas is wood gas which is created by gasification of wood or other biomass
• Depending on where it is produced, biogas can also be called swamp, marsh, landfill or digester gas
• Biogas contains,
• Methane -50-75%
• Carbon dioxide -25-50%
• Nitrogen -0-10%
• Hydrogen -0-1%
• Hydrogen sulfide -0-3%
• Oxygen -0-2%
• Biogas plants
• Materials used in biogas production
• The materials commonly used in biogas production are,
» Human & animal waste
» Crop residue
» Agro industrial waste
» Biomass combined with water (sewage)
» Energy crops- Maize, sunflower, wheat, grass
• Methods of biogas production
• Mainly biogas is produced using anaerobic digestion
• There are various methods & reactor types used to produce biogas
• But the production process has common steps though the methods are different
• stages of biogas production
• This natural, biological process takes place in three stages:
Hydrolysis :insoluble solids are broken down to monomers
Acidogenesis:monomers are converted to VFA
Methanogenesis:acids are converted to bio gas
• Different types of reactors
Type 1
• Influent is added to the reactor, and mixing is accomplished with gas mixers, mechanical
mixers, or recirculation pumps
• High installation and operating costs, high hydraulic retention times are required to achieve an acceptable level of degradation, signifying large reactor sizes
• Type 2
• The biomass forms sludge granules, producing a sludge bed which is completely retained in the reactor
• Allows for higher-strength wastewaters to be treated
• requires a significant amount of time, causing longer start-up times when compared to other reactors
• A diagram of type 2 reactor
• Contact Digester
• Retains biomass by separating and concentrating the solids in a separate reactor, returning these solids to the influent
• Solids separation can be achieved with gravity separators, solids thickeners, centrifuges, gravity belts, and membranes
• Sewage treatment
• Sludges from the primary and secondary treatment settling tanks are collected into an anaerobic digester
• Sludges contain cellulose, proteins, lipid and other insoluble polymers
• Anaerobic bacteria digest the sludge to methane and carbon dioxide
• Sewage treatment plant
• Using a biodigester
• Biodigester is a system that promotes decomposition of organic matter.
• It produces biogas, generated through the process of anaerobic digestion.
• Factors Affecting Biogas Production
Biogas yield is measured as
• m3 gas/kg volatile solids
• The maximum possible gas yield on complete digestion of carbohydrates (starch, cellulose, glucose) would be 0.8 m3kg.
• for fatty acids this value it is about 1.5 m3kg.
• proteins it is about 0.9 m3/kg.
This depends on,
• Type of waste
• Temperature during digester operation,
• Retention time (the period of time a given sample of waste/substrate stays in the digester/ fermenter before it flows out)
• Presence of toxic materials
• pH
• Stirring
• Carbon – Nitrogen Ratio
• Type of waste
Ex:
-Livestock & poultry wastes
-Crop residues
-Paper wastes
-Aquatic weeds
-Algae & seaweeds
• The yellow circles represents evolving biogas bubbles and the brown circles represent sludge granules. The upward liquid flow and uplifting action of gas bubbles causes the partial fluidization of the sludge bed and hydraulic mixing. The background is a scanning electron micrograph inside a sludge granule cultivated on sucrose-containing wastewater, show a diverse population of microorganisms.
• Temperature
• The choice of the temperature to be used is influenced by climatic considerations.
• Optimum process stability temperature should be carefully regulated within the a narrow range of operating temperature.
• Mesophilic fermentation at about 35°c gives the maximum gas yields,
•
• Thermophilic bacteria give best yields around 55°c.
• For sewage sludge, the gas yield at 20°c may be only 80% of that at 35°c.
• Retention time
• At high temperature bio – digestion occurs faster, reducing the time requirement.
• A normal period for the digestion of dung be two to four weeks.
• Gas yields increase with retention time since a greater proportion of the organic matter will be digested.
• Amount of OM vs retention time
• Toxic Materials
• Wastes & biodegradable residue are often accompanied by a variety of pollutants that could inhibit anaerobic digestion.
• Toxic components may include ammonia, SO42-, antibiotics, etc.
• Common toxic substances are
soluble salts of,
Copper
Zinc
Nickel
Mercury
Chromium
• Salts of
* Sodium
* Potassium
* Calcium
* Magnesium may be stimulatory or toxic in action.
• Pesticides & synthetic detergents may also be troublesome to the process.
• pH
• Low pH inhibit the growth of the methanogenic bacteria.
• A successful pH range for anaerobic digestion is 6.0 – 8.0.
• Efficient digestion occurs at a pH near neutrality.
• Low pH may be remedied by dilution or by the addition of lime.
• Carbon – Nitrogen Ratio
• The bacteria responsible for the anaerobic process require both elements
• They consume carbon roughly 30 times faster than nitrogen
• A carbon – nitrogen ratio of about 30:1 is ideal for the raw material fed into a biogas plant
• Stirring
• Stirring the slurry in a digester is always advantageous, if not essential
• If not stirred, the slurry will tend to settle out and form a hard scum on the surface, which will prevent release of the biogas
• Problem is much greater with vegetable waste than with manure, which will tend to remain in suspension
• Advantages of biogas
• provide better & cheaper fuel
• produce quality manure to improve soil fertility
• provide an effective way for sanitary disposal of human excreta
• use as a smokeless domestic fuel
• helps in generation of production employment
• Disadvantages of biogas
• Yields are lower due to the dilute nature of substrates
• The process is not very attractive economically on a large industrial scale
• New technologies cannot be used to enhance the efficiency of the process
• The process can be improved only by optimizing the environmental conditions of the anaerobic digestion
• Biogas contains some gases as impurities
• Uses of biogas
• electricity production
• Cooking
• water heating
• can replace compressed natural gas for use in vehicles
Friday, October 17, 2008
Non Traditional Animal Feed sri lanka
Ipil Ipil Leaf
Ipil-Ipil Leaf Meal
• The young foliage is very palatable to cattle.
• rich in protein and nutritious.
• leaves should not be fed to breeding animals.
• they may affect reproduction.
Toxicity
• The leaves and seeds contain the glucoside mimosine
• which may cause loss of hair in horses and young cattle.
• The treated material is allowed to stand for a week before being mixed with feeds .
• But little toxicity remains.
Nutrition Composition
(% dry matter)
How to Reduced Toxicity
• The addition of iron salts decreases toxicity.
• treated material is allowed to stand for a week before being mixed with feeds.
• The mimosine content can also be reduced by soaking in water and drying.
Cassava
Cassava
• Cultivated widely in the tropics and subtropics for its edible roots.
• cassava roots intended for human consumption
• It is possible to obtain from cassava more than 6 tons of crude protein per hectare.
Toxicity
• Cassava contain a glucoside, linimarin.
• which is acted upon by an enzyme to liberate prussic acid.
• These have to be processed before being used as feed.
How to Reduced Toxicity
• wash and squeeze them until the toxic substance is eliminated.
• toxic elements can also be removed by cooking or by drying slices of the roots for about two weeks.
Usage
• principal energy source for dairy cattle
• Cassava can replace almost all of the grain in the diets with little reduction in performance.
• Inclusion levels of up to 65%
• preferably pelleted, do not seem to affect health.
• Cassava leaf and stem meal has been used at the 35% level in dairy cow concentrates
Problems
• cassava feed has yielded similar egg production, although egg weight was significantly reduced.
• The forage has been used to provide by-pass protein to ruminants fed urea and molasses.
As % of dry matter
Groundnut
Groundnut
• These have proved to be an excellent feed and are also exceptionally palatable.
• Whole cured plants can be fed with advantage to dairy and beef cattle
Importance
• solid particles that consists of rich proteins, minerals which are utilised for making oil cakes.
• It is also used for animal foods and very necessary for poultry.
Amino acid composition as % of crude protein
Cotton Seed Poonac
Cotton Seed
• The cotton-seed consists of two parts: the hull, from which the staple cotton lint and linters arise, and the kernel, from which the oil and meal are obtained.
• The nutritive value of cottonseed products depends on proportions of husks and lint.
• often the whole seed is extracted for oil.
Importance
• Undecorticated oilcake is much richer in fibre and lower in protein.
• Cottonseed meal is an excellent protein supplement for cattle.
• the cottonseed cake is broken, the fibres can be seen.
• 1.7 tons of cottonseed yields about residual oil in hydraulic-press cake is usually between 4% and 8%
Toxicity
• seed embryo contains yellow pigment called gossypol.
• that cotton seeds may contain from 0.3-20 g/kg DM of gossypol
• which is an antioxidant and inhibitor and is toxic to monogastric animals.
• pigs and rabbits are the most sensitive.
• Both decorticated and undecorticated cottonseed meal have a constipating effect on cattle
• The general symptoms of gossypol toxicity are constipation, depressed appetite and loss of weight.
• Although acute toxicity is low, ingestion of a small amounts over a prolonged period can be lethal.
How to Reduced Toxicity
• The free gossypol content of cottonseed meal decreases during processing and varies according to the methods used.
• In new seed, free gossypol accounts for 0.4-1.4% of the weight.
• Processing conditions have to be carefully controlled because, binding of gossypol to lysine at high temperatures.
cotton cake As % of dry matter
Disadvantage
• Cottonseed meal has a relatively low rumen degradability.
• cottonseed is low in lysine
• Determination of the amount of free gossypol in a meal requires laboratory facilities.
Ipil-Ipil Leaf Meal
• The young foliage is very palatable to cattle.
• rich in protein and nutritious.
• leaves should not be fed to breeding animals.
• they may affect reproduction.
Toxicity
• The leaves and seeds contain the glucoside mimosine
• which may cause loss of hair in horses and young cattle.
• The treated material is allowed to stand for a week before being mixed with feeds .
• But little toxicity remains.
Nutrition Composition
(% dry matter)
How to Reduced Toxicity
• The addition of iron salts decreases toxicity.
• treated material is allowed to stand for a week before being mixed with feeds.
• The mimosine content can also be reduced by soaking in water and drying.
Cassava
Cassava
• Cultivated widely in the tropics and subtropics for its edible roots.
• cassava roots intended for human consumption
• It is possible to obtain from cassava more than 6 tons of crude protein per hectare.
Toxicity
• Cassava contain a glucoside, linimarin.
• which is acted upon by an enzyme to liberate prussic acid.
• These have to be processed before being used as feed.
How to Reduced Toxicity
• wash and squeeze them until the toxic substance is eliminated.
• toxic elements can also be removed by cooking or by drying slices of the roots for about two weeks.
Usage
• principal energy source for dairy cattle
• Cassava can replace almost all of the grain in the diets with little reduction in performance.
• Inclusion levels of up to 65%
• preferably pelleted, do not seem to affect health.
• Cassava leaf and stem meal has been used at the 35% level in dairy cow concentrates
Problems
• cassava feed has yielded similar egg production, although egg weight was significantly reduced.
• The forage has been used to provide by-pass protein to ruminants fed urea and molasses.
As % of dry matter
Groundnut
Groundnut
• These have proved to be an excellent feed and are also exceptionally palatable.
• Whole cured plants can be fed with advantage to dairy and beef cattle
Importance
• solid particles that consists of rich proteins, minerals which are utilised for making oil cakes.
• It is also used for animal foods and very necessary for poultry.
Amino acid composition as % of crude protein
Cotton Seed Poonac
Cotton Seed
• The cotton-seed consists of two parts: the hull, from which the staple cotton lint and linters arise, and the kernel, from which the oil and meal are obtained.
• The nutritive value of cottonseed products depends on proportions of husks and lint.
• often the whole seed is extracted for oil.
Importance
• Undecorticated oilcake is much richer in fibre and lower in protein.
• Cottonseed meal is an excellent protein supplement for cattle.
• the cottonseed cake is broken, the fibres can be seen.
• 1.7 tons of cottonseed yields about residual oil in hydraulic-press cake is usually between 4% and 8%
Toxicity
• seed embryo contains yellow pigment called gossypol.
• that cotton seeds may contain from 0.3-20 g/kg DM of gossypol
• which is an antioxidant and inhibitor and is toxic to monogastric animals.
• pigs and rabbits are the most sensitive.
• Both decorticated and undecorticated cottonseed meal have a constipating effect on cattle
• The general symptoms of gossypol toxicity are constipation, depressed appetite and loss of weight.
• Although acute toxicity is low, ingestion of a small amounts over a prolonged period can be lethal.
How to Reduced Toxicity
• The free gossypol content of cottonseed meal decreases during processing and varies according to the methods used.
• In new seed, free gossypol accounts for 0.4-1.4% of the weight.
• Processing conditions have to be carefully controlled because, binding of gossypol to lysine at high temperatures.
cotton cake As % of dry matter
Disadvantage
• Cottonseed meal has a relatively low rumen degradability.
• cottonseed is low in lysine
• Determination of the amount of free gossypol in a meal requires laboratory facilities.
Thursday, September 25, 2008
Grain legumes
legumes are belonng to the family Fabaceae,
Or a fruit of that plants.Mainly this crops are grown for agricultural purposes
Also people called it as pulses.
These are cultivated mainly for their seeds.
The seeds are used for human and animal consumption or for the production of oils for industrial uses.
Include beans, green gram, peas
Tuesday, September 23, 2008
Water & Sewage treatment
Water treatment
• Water is collected from reservoirs or wells
• Flocculation removes suspended particles such as clay
• Filtration removes larger particles and protozoans as well as many bacteria
• Water is then treated with chlorine or ozone to remove pathogens and other microorganisms
Sewage treatment
• Primary treatment
– Sewage is held in settling tanks
– Heavy particles settle out
– Lighter particles are skimmed off the top
• Secondary treatment
– Sewage is aerated
– Bacteria grow and use organic matter to lower the BOD
– Activated sludge
– Trickling filters
Sewage treatment …
• Disinfection and release
• Sludge digestion
anaerobic digestion produces methane
Sewage treatment …
• Septic tanks
• Oxidation ponds
• Tertiary treatment
– All nutrients are removed and water is used for drinking
• Water is collected from reservoirs or wells
• Flocculation removes suspended particles such as clay
• Filtration removes larger particles and protozoans as well as many bacteria
• Water is then treated with chlorine or ozone to remove pathogens and other microorganisms
Sewage treatment
• Primary treatment
– Sewage is held in settling tanks
– Heavy particles settle out
– Lighter particles are skimmed off the top
• Secondary treatment
– Sewage is aerated
– Bacteria grow and use organic matter to lower the BOD
– Activated sludge
– Trickling filters
Sewage treatment …
• Disinfection and release
• Sludge digestion
anaerobic digestion produces methane
Sewage treatment …
• Septic tanks
• Oxidation ponds
• Tertiary treatment
– All nutrients are removed and water is used for drinking
Thursday, September 11, 2008
BIO FERTILIZER
What Is Bio Fertilizer
. Ready to use live formulates of such beneficial microorganisms which on application to seed, root or soil mobilize the availability of nutrients by their biological activity in particular, and help build up the micro-flora and improve the soil health in general
Why should use biofertilizers?
. modern agriculture is getting more and more dependent upon the steady supply of synthetic inputs. Thus,
¨Decrease in the quality of crop products
¨spoil the soil properties, Osmatic pressure, pH, Conductivity and water holding capacity
¨Affect adversly on population of micro-organisms and other parameters
Types of Bio Fertilizer
Nitrogen fixers
. Convert nitrogen from the atmosphere into ammonium (NH4) or nitrate (NO3) ions which are readily useable by plants
. These include Rhizobium, Azatobacter, Azospirillum, Blue Green Algae (BGA) and Azolla
. secrete growth promoting substances
. Contained in the root nodules or Free living
Nitrogen fixers - Bacteria
. Rhizobium
¨Are soil bacteria that fix
nitrogen after becoming
established inside root nodules
of legumes
¨They cannot independently fix nitrogen, and requires a plant host
¨Morphologically they are generally gram negative, motile, non-sporulating rods
Nitrogen fixers - Bacteria
. Azospirillum
¨Easy adaptability and limited host specificity
¨Lives inside the cortical cells and xylem vessels of plant roots
¨Have ability to fix 25-40 kg N/ha/year
Nitrogen fixers - Bacteria
. Azospirillum
¨Secrete growth promoting substances like gibberellic acid and IAA which enhance root proliferation and growth of crop plants
Nitrogen fixers – Blue Green
. Anabaena
¨genus of filamentous cyanobacteria
¨they form symbiotic relationships with certain plants, such as the mosquito fern
Azolla
. They form a symbiotic relationship with the blue-green alga which fixes atmospheric nitrogen, giving the plant access to the essential nutrient
. grow at great speed - doubling its biomass every two to three days
. 30 – 100 kg N/ha/Year
Yield increases
20 – 25 %
Phosphorous Solubilizing Bacteria
. Solubilize unavailable organic & inorganic forms of phosphorus (80%)
. Organic P slowly mineralized by the action of phosphatases
. Inorganic P solubilized by the action of organic and inorganic acids
. Belonging to the genera bacillus and pseudomonas
Phosphorous Solubilizing Bacteria
. Pseudomonas
¨genus of gamma proteobacteria
¨Gram-negative, rod-shaped and polar-flagella bacteria
¨Known to produce amino acids and growth promoting substances which help in better growth of plants
¨About 30 kg P/ha/annum
Nutrients Up Take Enhancing Fungus
. Increase water uptake in plant
. Increase mineral uptake (especially P, Cu & Zn)
. Limits uptake of (Al, As, Ti, Ba & Cd)
. Two types Ectomycorrhizae and Endomycorrhizae
Nutrients Up Take Enhancing Fungus
. Ectomycorrhizae
¨Form a sheath around the root
¨Hyphae grow between the spaces in the cortical root cell
¨No cellular penetration by the hyphae
¨Members of the basidomycetes or the ascomycetes
Nutrients Up Take Enhancing Fungus
. Endomycorrhizae
¨Hyphae form arbuscles (Bulb structure)
¨Called VAM (vesicular arbuscular mycorrhizae)
¨Direct cell to cell
exchange of nutrients
¨Hyphae grow into
intercellular spaces
Sulphur Solubilizing Microbes
. Thiobacillus
¨colorless, rod-shaped, Gram-negative bacteria with polar flagella
¨They possess an iron oxidase, which allows them to metabolize metal ions
Sulphur Solubilizing Microbes
. Thiobacillus
¨ they require inorganic molecules as an electron donor and inorganic carbon (such as carbon dioxide) as a source.
¨ They obtain nutrients by oxidizing iron and sulfur with O2
Enzymatic Biofertilizer
. Microorganism having ability to secret enzymes and external enzymes
. which on application to seed, root or soil mobilize the availability of nutrients by their biological activity
Decomposers
. Break down organic waste and dead organisms.
. Releases key ions such as nitrates, phosphates and sulfates for use by other organisms
. Many Kinds of Bacteria and Fungi assist in this process
benefits of using bio fertilizers
. Increase crop yield by 20-30%
. Replace chemical nitrogen and phosphorus by 25%
. Stimulate plant growth
benefits of using bio fertilizers
. Activate the soil biologically
. Restore natural soil fertility
. Provide protection against drought and some soil borne diseases
. Cost effective
. Eco-friendly
How biofertilizers are applied to crops
. Seed treatment
¨seeds are treated with nitrogenous biofertilizer and dried in shade. The treated seeds have to be sown as soon as possible
. Seedling root dip
¨Recommended biofertilizers are mixed in this water and the roots of seedlings are dipped for 8-10 hrs
How biofertilizers are applied to crops
. Soil treatment
¨The recommended biofertilizers are mixed in compost and kept overnight. This mixture is incorporated in the soil at the time of sowing or planting
Disadvantages of using Bio Fertilizers
. Biofertilizer packets need to be stored in cool and dry place away from direct sunlight and heat.
. Right combinations of biofertilizers have to be used.
. As Rhizobium is crop specific, one should use for the specified crop only.
Disadvantages of using Bio Fertilizers
. Other chemicals should not be mixed with the biofertilizers
. Biofertilizers are live product and require care in the storage
Potentials
. Biofertilizers will help solve such problems as increased salinity of the soil and chemical run-offs from the agricultural fields
. Thus, biofertilizers are important if we are to ensure a healthy future for the generations to come
. Ready to use live formulates of such beneficial microorganisms which on application to seed, root or soil mobilize the availability of nutrients by their biological activity in particular, and help build up the micro-flora and improve the soil health in general
Why should use biofertilizers?
. modern agriculture is getting more and more dependent upon the steady supply of synthetic inputs. Thus,
¨Decrease in the quality of crop products
¨spoil the soil properties, Osmatic pressure, pH, Conductivity and water holding capacity
¨Affect adversly on population of micro-organisms and other parameters
Types of Bio Fertilizer
Nitrogen fixers
. Convert nitrogen from the atmosphere into ammonium (NH4) or nitrate (NO3) ions which are readily useable by plants
. These include Rhizobium, Azatobacter, Azospirillum, Blue Green Algae (BGA) and Azolla
. secrete growth promoting substances
. Contained in the root nodules or Free living
Nitrogen fixers - Bacteria
. Rhizobium
¨Are soil bacteria that fix
nitrogen after becoming
established inside root nodules
of legumes
¨They cannot independently fix nitrogen, and requires a plant host
¨Morphologically they are generally gram negative, motile, non-sporulating rods
Nitrogen fixers - Bacteria
. Azospirillum
¨Easy adaptability and limited host specificity
¨Lives inside the cortical cells and xylem vessels of plant roots
¨Have ability to fix 25-40 kg N/ha/year
Nitrogen fixers - Bacteria
. Azospirillum
¨Secrete growth promoting substances like gibberellic acid and IAA which enhance root proliferation and growth of crop plants
Nitrogen fixers – Blue Green
. Anabaena
¨genus of filamentous cyanobacteria
¨they form symbiotic relationships with certain plants, such as the mosquito fern
Azolla
. They form a symbiotic relationship with the blue-green alga which fixes atmospheric nitrogen, giving the plant access to the essential nutrient
. grow at great speed - doubling its biomass every two to three days
. 30 – 100 kg N/ha/Year
Yield increases
20 – 25 %
Phosphorous Solubilizing Bacteria
. Solubilize unavailable organic & inorganic forms of phosphorus (80%)
. Organic P slowly mineralized by the action of phosphatases
. Inorganic P solubilized by the action of organic and inorganic acids
. Belonging to the genera bacillus and pseudomonas
Phosphorous Solubilizing Bacteria
. Pseudomonas
¨genus of gamma proteobacteria
¨Gram-negative, rod-shaped and polar-flagella bacteria
¨Known to produce amino acids and growth promoting substances which help in better growth of plants
¨About 30 kg P/ha/annum
Nutrients Up Take Enhancing Fungus
. Increase water uptake in plant
. Increase mineral uptake (especially P, Cu & Zn)
. Limits uptake of (Al, As, Ti, Ba & Cd)
. Two types Ectomycorrhizae and Endomycorrhizae
Nutrients Up Take Enhancing Fungus
. Ectomycorrhizae
¨Form a sheath around the root
¨Hyphae grow between the spaces in the cortical root cell
¨No cellular penetration by the hyphae
¨Members of the basidomycetes or the ascomycetes
Nutrients Up Take Enhancing Fungus
. Endomycorrhizae
¨Hyphae form arbuscles (Bulb structure)
¨Called VAM (vesicular arbuscular mycorrhizae)
¨Direct cell to cell
exchange of nutrients
¨Hyphae grow into
intercellular spaces
Sulphur Solubilizing Microbes
. Thiobacillus
¨colorless, rod-shaped, Gram-negative bacteria with polar flagella
¨They possess an iron oxidase, which allows them to metabolize metal ions
Sulphur Solubilizing Microbes
. Thiobacillus
¨ they require inorganic molecules as an electron donor and inorganic carbon (such as carbon dioxide) as a source.
¨ They obtain nutrients by oxidizing iron and sulfur with O2
Enzymatic Biofertilizer
. Microorganism having ability to secret enzymes and external enzymes
. which on application to seed, root or soil mobilize the availability of nutrients by their biological activity
Decomposers
. Break down organic waste and dead organisms.
. Releases key ions such as nitrates, phosphates and sulfates for use by other organisms
. Many Kinds of Bacteria and Fungi assist in this process
benefits of using bio fertilizers
. Increase crop yield by 20-30%
. Replace chemical nitrogen and phosphorus by 25%
. Stimulate plant growth
benefits of using bio fertilizers
. Activate the soil biologically
. Restore natural soil fertility
. Provide protection against drought and some soil borne diseases
. Cost effective
. Eco-friendly
How biofertilizers are applied to crops
. Seed treatment
¨seeds are treated with nitrogenous biofertilizer and dried in shade. The treated seeds have to be sown as soon as possible
. Seedling root dip
¨Recommended biofertilizers are mixed in this water and the roots of seedlings are dipped for 8-10 hrs
How biofertilizers are applied to crops
. Soil treatment
¨The recommended biofertilizers are mixed in compost and kept overnight. This mixture is incorporated in the soil at the time of sowing or planting
Disadvantages of using Bio Fertilizers
. Biofertilizer packets need to be stored in cool and dry place away from direct sunlight and heat.
. Right combinations of biofertilizers have to be used.
. As Rhizobium is crop specific, one should use for the specified crop only.
Disadvantages of using Bio Fertilizers
. Other chemicals should not be mixed with the biofertilizers
. Biofertilizers are live product and require care in the storage
Potentials
. Biofertilizers will help solve such problems as increased salinity of the soil and chemical run-offs from the agricultural fields
. Thus, biofertilizers are important if we are to ensure a healthy future for the generations to come
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