2. IMPROVEMENT IN FOOD
PRODUCTION
• Food is organic, energy rich, non-poisonous,
edible and nourishing substance.
• Synthesized by green plants.
• To meet the increasing demand of food, it is
important to improve the quality and the
quantity of food production.
• Plant breeding & animal breeding help us to
increase the food production.
2
3. BIOFORTIFICATION
• A method in which crops are breed for having
higher levels of vitamins, minerals & fats.
• Malnutrition problems can be overcome.
• It focuses on making plants more nutritive as
they grow.
• Biofortification can be achieved through
conventional selective breeding & r-DNA
technology.
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4. Objectives Examples
Protein content & quality 1. Fortified maize having twice the
amount of amino acids - lysine &
tryptophan.
2. Wheat - Atlas 66
Oil content & quality 1. High unsaturated fatty acids of
soyabean, mustard & flax seeds.
2. Oleic acid (omega 9) fatty acids of
soyabean.
Vitamin content & quality 1. Carrot & spinach has more
vitamin A & minerals.
2. High provitamin golden rice.
3. Vit- C enriched bitter gourd,
tomato.
Micronutrient content & quality 1. Iron fortified rice has 5 times
more iron.
2. Zinc fortified wheat, rice, beans &
sweet potato.
4
5. MICROBES IN FOOD PRODUCTION
PRODUCT PRODUCED BACTERIA REQUIRED REACTIONS OCCURING
Dosa, Dhokala, Idili Leuconostoc, Streptococcus CO2 produced causes
puffing up of dough.
Curd & buttermilk Lactobacillus acidophilus Lactose converted to lactic
acid. Lactic acid causes
coagulation & partial
digestion of milk protein
casein.
Yogurt Streptococcus thermophilus
Lactobacillus bulgaricus
Curdling of milk
cheese Penicillium roquefortii
P. camembertii
Propionibactrium shermanii
Whey is ripened with
mould.
Large amount of CO2
production.
5
6. Microbes as the source of food
• Some Microbes are rich in proteins & vitamins.
They are directly used as source of food.
• Single cell protein (SCP) denotes dead & dried
cells of microbes.
• Bacteria -Rhodobacter capsulatus
• Algae -Spirulina, Chorella
• Molds -Aspergillus, Fusarium
• Yeasts -Saccharomyces, Candida
• Mushroom & truffles– Agaricus,
Pleurotus.
Pleurotus
Spirulina
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7. ROLE OF MICROBES IN INDUSTRIES
PRODUCTION OF ALCOHOLIC BEVERAGES
• Microbes used- saccharomyces cerevisiae var.
ellipsoidis.
• Fermentation of malted cereals and fruit juices are
done to produce Ethanol.
• Wine & beer are produced without distillation.
• Whiskey, brandy & rum are distilled beverages.
• The famous wine of Goa is fenny.
• It is prepared by fermenting fleshy pedicels of Cashew
fruits.
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9. Production of organic acids
Organic acids Microbes used Uses
Citric acid Aspergillus niger Confectionary
Gluconic acid Aspergillus niger In medicine for
solubility of Ca ions.
Fumaric acid Rhizopus arrhizus Resins as wetting
agents
Acetic acid (vinegar) Acetobacter acetii 1% dilution is used
in antiseptic.
9
10. Production of Vitamins
• These are organic nitrogenous compounds.
• Microbes are capable of synthesizing vitamins.
• Eg. Thiamine, riboflavin, pyridoxine, folic acid,
biotin, pantothenic acid, vit-B12, ascorbic
acid, beta carotene (provitamin A) &
ergosterol (provitamin D).
Vitamin Microbial source
Vita B 2 Neurospora gossypii
Eremothecium ashbyi
Vita B 12 Pseudomonas denitrificans
Vita C Aspergillus niger
10
12. Production of enzymes
Enyzmes Mirobial source Uses
Invertase Saccharomyces
cerevisiae
Fermentation process of
bread & beverages
Pectinase Scelortinia libertine
Aspergillus niger
Fruit juice industries for
improving the quality of
juices.
Extraction of olive oil &
carotenoids.
Lipase Candida lipolytica In textile industries.
Detergents, leather, cosmetic
industries, animal feed &
agricultural industries.
Cellulase Trichoderma
konigii
Textile, paper & pulp
industries.
Extraction of carotenoids. 12
13. Gibberellin production
• A plant growth horome synthesized by plants and
fungus- Gibberella fijikouri
• It promotes growth by stem elongation.
• It induce parthenocarpy in tomato, apple, pear, etc.
• Breaking seed dormancy of seed & promotes
germination.
• Inducing flowering in long day plant.
• It promotes bolting.
• It inhibits growth of root, delays
senescence & prevent abscission.
• Increase the fruit size of grapes.
Eg . Thompson varieties.
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14. Microbes in sewage
• Matter carried off in drainage.
• Discharged water from hospital, slaughter
house, animal dung, industrial waste, tannery,
pharmaceutical waste, etc.
Composition of sewage.
• It contains approximately 99.5% – 99.9% water
& 0.1 – 0.5% inorganic and organic matter in
suspended and soluble form.
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15. Micro organisms in sewage
• Bacteria, viruses, fungi, protozoa, nematode,
algae, etc are found in sewage.
• Raw sewage may contains millions of bacteria
per mL. eg. Coliforms, fecal Streptococci,
Bacilli, most bacteria of intestinal tract of
humans.
15
16. Sewage treatment process
1. Preliminary treatment –
2. Primary treatment –
3. Secondary treatment –
4. Tertiary treatment –
Screening Grit setting Primary treatment
Secondary
treatment
Aeration
tank
Treated
Effluent
Anaerobic bioreactor
(Digester)
Waste
water
Preliminary treatment to
remove heavy solids
Removal of suspended
solid particles
Tertiary treatment
(anaerobic bacteria)
(Aerobic bacteria)
Waste to recycle
Sludge cake
to dispose
Settled sewage
Activated sludge
16
18. 1. Preliminary treatment
1. Screening-
• Sewage water is filtered to remove suspended
materials.
• Done through net or screen.
2. Grit chamber-
• Chamber contains large stones & brick ballast.
• Coarse particles settle down through gravity.
18
19. 2. Primary treatment
• Sewage water is pumped into primary
sedimentation tank.
• 50- 60% od suspended solids settle down.
• 30- 40% of coliform (bacteria)are removed.
• The organic matter which settle down is called
primary sludge which is removed by
mechanically operated devices.
19
20. 3. Secondary treatment
(Biological treatment)
• Primary effluent is passed into large aeration tank.
• Constantly agitated mechanically.
• Air is pumped.
• Aerobic bacteria is grown to form
flocs.
• Flocs are the masses of the bacteria held together
by slime & fungal hyphae to form mesh like masses.
• Organic matter reduces BOD (Biological Oxygen
demand) of the effluent.
Flocs
20
21. 4. Tertiary treatment
• The effluent is passed into settling tank after reduction
of BOD.
• Sedimentation of bacterial flocs are done.
• The sediments are called activated sludge.
• Small part of this is passed into aeration tank & major
part is pumped into anaerobic sludge digesters.
• In digester, anaerobic bacteria grows & digest the flocs.
• Methane, H2S & CO2 are produced during digestion.
• Chlorination of effluent is done & treated water is
released into river & streams.
• Digested Sludge is disposed.
21
22. Microbes in energy generation
• Biogas is a non-conventional & renewable
source of energy.
• It is obtained by microbial fermentation of
biological waste.
• It is mixture of CH4 (50-60%), CO2 (30-40%),
H2S (0-3%) & other gases (CO, N2, H2 ) in
traces.
22
23. Biogas production
• Models of biogas plants used are KVIC & IARI.
• Biogas plant has a
• Digester & gas holder.
• Digester- concrete
brick & cement/ steel
• Partly buried in soil.
• Gas holder-collect gas
• Charge pit-cow dung
is feed.
23
24. Anaerobic digestion in biogas plant
1. Hydrolysis / solublization
• Slurry is made by animal dung & equal amount
of water.
• It is feed in digester.
• Anaerobic hydrolytic bacteria (Clostridium,
Pseudomonas) hydrolyze carbohydrate into
simple sugars, proteins into amino acids &
lipids into fatty acids.
24
25. 2. Acidogenesis
• Facultative anaerobic , acidogenesis bacteria
& obligate anaerobic organisms convert
simple organic material into acids like formic
acid, acetic acid, H2 & CO2 .
3. Methanogenesis
• Anaerobic methanogenic bacteria –
Methanobacterium, Methanococcus convert
acetate, H2 & CO2 into methane, CO2 & H2O
and other products.
25
26. Reactions in the biogas
12 CH3COOH 12 CH4 + 12 CO2
(Acetic acid) (Methane)
1
4 H.COOH CH4 + 3CO2 + 2 H2O
(Formic acid)2
CO2 + 4H2 CH4 + 2H2O3
26
27. Benefits of biogas
1. Cheap, safe & renewable source of energy.
2. Easily generated, stored & transported.
3. Used for domestic lighting, cooking, street
lighting & for small scale industries.
4. Burns with blue flame without smoke.
5. Improves sanitation of the surrounding.
6. Eco- friendly & does not cause pollution &
imbalance of the environment.
7. Sludge is used as fertilizer.
27
28. Microbes as biocontrol agents
• The natural method of eliminating & controlling
insects, pests and other disease causing agents by
their natural biological enemies is called
biocontrol / biological control .
• Microbes like fungi, bacteria & protozoans are
used as biocontrol agents.
• They acts in 3 ways –
1. Cause disease to the pest.
2. Compete with them.
3. Kill them.
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29. Examples of microbial bio-control
1. Bacillus thuringiensis (Bt)-
• Destroys butterfly, caterpillars when dried spores of
(Bt) are mixed with water & sprayed onto plants like
Brassica & fruit trees.
• When the spores are eaten by the insects, toxins (cry
protein) are produced in their gut & they die.
2. Trichoderma species –
• Free-living fungi found in rhizosphere.
• They produce toxins like viridin, gliotoxin, gliovirin,
etc.
• These toxins inhibits other soil borne pathogens
attacking root, rhizomes, etc causing Rot disease. 29
30. Microbial Pesticides & their host
Pathogen Host
Bacteria
Bacillus thuringiensis, B. paplliae,
B. lentimorbus
Caterpillars, cabbage worms, adult
beetle, etc.
Fungi
Beavuria bassiana,
Entomophthora pallidaroseum
Zoopthora radicans
Aphid crocci, A. unguiculata,
Mealy bugs, mites, white flies, etc.
Protozoans
Nosema lacustae Grasshopper, caterpillars, crickets.
Viruses
Nucleopolyhedro virus (NPV)
Granulovirus (GV)
Caterpillars, Gypsy moth, ants, wasps
& Beetles.
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31. Bioherbicides
• Weeds are unwanted plants & compete with
the main farm land.
• Some microbes are used to kill the
dicot weeds & are called
bioherbicides.
• Microbial Herbicides & their host-
Pathogenic fungi as
Mycoherbicides
Host
Phytophthora palmivora Controls milk weed in
Orchards
Alternaria crassa Controls water hyacinth
Fusarium spp. Control most of the weeds.
Phytophthora
31
32. Bacterial pathogens as
herbicides
Host
Pseudomonas spp. Attacks several weeds
Xanthomonas spp. Attacks several weeds
Agrobacterium spp. Attacks several weeds
Insects as herbicides Host
Tyrea moth Controls the weed Senecio
jacobeac
Cactoblastis cactorum Controls cacti weeds
Tyrea moth
Pseudomonas
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33. Microbes as Biofertilizers
• Biofertilizers are nitrogen fixing, living
microorganisms which enrich the nutrient
quality of soil.
• They are commercial prepared ready to use
live bacterial or fungal formulations.
• They play vital role in maintaining long term
soil fertility & sustainability.
33
34. Types of biofertilizers
1. Nitrogen fixing Biofertilizers-
• They fix atmospheric N2 into
nitrites & nitrates via ammonia.
• They are called as Diazotrophs
& are of 2 types.
Symbiotic N2 fixing microorganisms-
• Eg. Rhizobium, Anabaena, Frankia.
• They are associated with the roots
of plants.
Anabaena
Frankia34
35. B) Free living/ non-symbiotic N2 fixing
microorganisms-
• Eg. Azotobacter, Nostoc , Clostridium,
Beijerinkia, Klebsiella, etc.
Clostridium Nostoc
35
36. Phosphate solubilizing biofertilizers
• Some Bacterial species solubilize the
insoluble inorganic phosphate compounds.
• Eg. Pseudomonas striata, Bacillus polymyxa,
Agrobacterium, Microccocus, Aspergillus spp.,
etc.
Aspergillus
Microccocous
36
37. Compost making fertilizers
• The process in which the organic matter is
converted into humus or compost.
• Microorganisms such as bacteria, fungi,
actinobacteria, protozoa & rotifers.
37
38. Cyanobacteria as biofertilizers
• Many cyanobacteria are aquatic or terrestrial, free living
or symbiotic, aerobic, photosynthetic, N2 fixing,
herterocystous or non-heterocystous forms.
• Eg. Anabaena, Nostoc, Plectonema, Oscillatoria, etc.
• Anabaena, Nostoc & Tolypothrix are associated with
lichens.Anabaena is associated with plants like Azolla &
Cycas.
OscillatoriaAnabaena –
Azolla 38
39. Fungal biofertilizers
• Mycorrhiza is a fungus.
• It forms symbiotic association
with rhizomes & roots of
higher plants growing in thick
humid forests.
1. Ectomycorrhiza-
• They have well develop
mycelium forming mantle
outside the roots.
• This increases absorptive
surface area of roots & accelerates uptake of water &
nutrient (NPK, Ca).
• Some hyphae of mycorrhizal fungus penetrate into root
& forms hartig-net in the intercellular spaces of root
cortex.
39
40. 2. Endomycorrhizae –
• They grow in
between & within
the cortical cell of
roots.
• Fungal hyphae
penetrates the cells
& forms arbuscules
& vesicles.
• Arbuscules are intracellular whereas vesicles are
mostly intercellular.
• Also called as VAM- Vesiculo Arbuscular Mycorrhizae.
• The plants with VAM can grow well in less irrigated
lands.
• They increase the productivity of field.
40
41. Advantages of Mycorrhiza
1. Selective absorption of P, Zn, Cu, Ca, N, Mn,
Bo & Fe.
2. Enhance water uptake in plants.
3. Induce growth by secreting hormones.
4. Protects host plants from the other microbes,
by secreting antibiotics.
41
42. Biofertilizer microorganisms
1. Rhizobium –
• These are rod shaped, motile
aerobic, gram –ve, non spore
forming N2 fixing bacteria.
• They have Nod & Nif gene.
• They form symbiotic
association with roots of
leguminous plants.
• Bring about nodule formation on the roots &
multiply inside the nodule.
• They fix atmospheric N2 into organic forms.
• Eg. Rhizobium leguminosarum is specific to pea &
R. phaseoli to beans.
42
43. 2. Azotobacter –
• It is free living, aerobic, non-
photosynthetic N2 fixing, non-
nodule forming bacteria.
• They are associated with
grasses & certain plants.
• It is used as biofertilizer in non leguminous
plants like rice, cotton, vegetables, etc.
Azotobacter
43
44. 3. Azospirillium-
It is free living, aerobic N2 fixing bacterium.
Associated with roots of corn, wheat, jowar, etc.
It fixes about 20-40 kg N/ha in non-leguminous
plants such as millets, cereals, cotton, oil seed,
etc.
44
45. 4. Anabaena
• It is multicellular cyanobacteria.
• It Fix N2 & form symbiotic association with
Cycas & Anthoceros (forming coralloid root).
• They have heterocyst as a site of N2 fixation.
45
46. 5. Azolla –
• It is free floating aquatic fern.
• They have floating rhizome with
small overlapping bilobed leaves
& roots.
• The leaf shows dorsal &
ventral lobe.
• In the dorsal lobe, Anabaena
filaments are present in
arenchyma tissue.
• They fix nitrogen.
• Azolla is used as biofertilizer
in rice field.
Anabaena
46
47. Benefits of Biofertilizers
1. Low cost & can be used by marginal farmers.
2. Free from pollution hazards.
3. Increase soil fertility.
4. BGA secret growth promoting substances,
organic acids, proteins & vitamins.
5. Azotobacter supplies nitrogen & antibiotics to
the soil.
6. Biofertilizers increase physico - chemical
properties of soil- like texture, structure, pH,
water holding capacity of soil by providing
nutrient & organic matter.
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