Economic importance of bacteria their uses and application in everyday lif. Harms by bacteria different disease and profit of bacteria to be available in our environment and fora and funa. Different types of disease which are caused by bacteria to animals,humans and plants. Roles in agriculture , Decay and Decomposition, Role in medicine , Role in biofuels. Biotechnology Genetic engineering

1. Economic importance of
Bacteria

2. Importance
• Bacteria play important roles in different fields
such as agriculture, industry, medical
background etc.

3. Beneficial Roles
• Role in Agriculture
• Role of Bacteria in Industries
• Role of Bacteria in Medicine
• Production of fuel
• Combating against pollution including Disposal
of sewage
• Biotechnology
• Genetic engineering
• Digestion

4. Role in agriculture
• Decay and decomposition: scavenging role
• Soil fertility including Nitrification
• Production of organic manure
• Preparation of ensilage
• Biopesticide
• Biofertilizer
• Crop rotation

5. Decay and decomposition
• Soil bacteria play an important role in brining about decomposition of organic
matter. They serve a double purpose.
• In the first instance they act as scavengers removing harmful waste from the
earth.
• Secondly, they return it to the soil as plant food.
• The dead bodies and wastes of organisms (both plants and animals) are
decomposed by the activities of the saprophytic bacteria.
• In consequence a variety of elements of minerals of the earth such as carbon,
oxygen, hydrogen, sulphur and phosphorus which make up their bodies are
reduced to simple compounds such as carbon monoxide, water, nitrates,
sulphates and phosphates.
• Some of these go back to the soil and the rest to the air. From the soil they can be
absorbed as plant food.
• This activity of the bacteria is used in sewage disposal system of cities. The
bacterial action on the city’s sewage promotes decay.
• As a result water is finally purified and changed into an odourless and valuable
fertiliser instead of a dangerous and expensive waste product.

6. Decay and decomposition
Scavenging role
• Saprophytic bacteria obtain food from organic
remains such as animal excreta, fallen leaves,
meat etc.
• They decompose these substances by action
of digestive enzymes aerobically or
anaerobically (known as fermentation). Thus
they help in sanitation of nature, so also
known as scavengers. E.g. Pseudomonas

7. Soil fertility
• Some bacteria play an important role in maintaining and others in increasing soil
fertility. The fertility of soil is proportional to its nitrogen content. Nitrogen is an
essential ingredient of all living protoplasm.
• All growing plants, therefore, require it in their metabolism.
• Atmosphere, no doubt, is four-fifths (80%) nitrogen, green plants generally are
unable to use it.
• They mostly absorb it as nitrates and to some extent as ammonia from the soil.
• Continuous absorption of these salts results in their exhaustion in the soil. Nearly
all fertilisers for the soil include a large proportion of such soluble nitrogen
compounds to promote plant growth.
• In nature the presence of a regular supply of these salts is ensured by bacteria of
certain types. These bacteria which function as Nature’s farmers belong to three
categories, namely, ammonifying bacteria, nitrifying bacteria and nitrogen-fixing
bacteria.
• They are the agents of maintaining a continual circulation of nitrogen in nature
between the plant world, in soil and the atmosphere. The series of changes
through which the nitrogen passes due to the activities of these organisms
constitute the nitrogen cycle.

8. Soil fertility: types of bacteria
• Ammonifying Bacteria
• Nitrifying Bacteria
• Nitrogen-fixing Bacteria

9. Ammonifying Bacteria and
ammonification
• The saprophytic bacteria break down the proteins and other
nitrogen containing remains of the plant and animal origin in
the soil to amino acids by secreting enzymes.
• The ammonifying bacteria convert amino acids and other
compounds into ammonia. The process is called
ammonification—bacillus, pseudomonas and proteus
• The liberated ammonia may combine with carbon dioxide and
water in the soil to form ammonium carbonate.
• A few plants such as the common cereals can make use of
ammonium compounds as a source of nitrogen. The majority
of plants, however, cannot absorb ammonium compounds as
a source of nitrogen.

10. Nitrification
• Ammonia is very soluble. It moves in the soil
rapidly and is acted upon by microorganisms
of the category of chemosynthetic autotrophs
in the soil.
• They are the nitrifying bacteria such as
Nitrosomonas and Nitrobacter. They form
nitrates from ammonium compounds
• This nitrifying bacteria convert nitrogen from
the unavailable form of ammonium salts to
the available nitrates. This process converting
unavailable ammonium salts into available
nitrates is called nitrification

11. Nitrifying Bacteria
• Nitrosomanas and Nitrococcus convert
ammonium salt to nitrites.
• Nitrites are further changed to nitrates
by Nitrobacter and Nitrocystis.
• It enables plants to uptake nitrogen.

12. Nitrosomonas oxidizes ammonium carbonate to
nitrous acid liberating energy. The nitrous acid
then combines with bases in the soil forming
potassium nitrite.
Nitrobacter oxidizes nitrites to nitrates again
liberating energy.
Neither the ammonifying nor the nitrifying bacteria
add to the total quantity of combined nitrogen
in the soil.
Reactions

13. Nitrogen fixation
• A considerable amount of nitrogen is lost by denitrification and through drainage.
The loss must be made good by equal gains if the soil fertility is to be maintained.
• The electric discharges in the atmosphere bring about the formation of traces of
nitrogen compounds which are washed to the soil by rain water. The largest
additions, however, come from a biological fixation process through the activity of
two types of nitrogen-fixing bacteria.
• Some of them live free in the soil and others in the root nodules of leguminous
plants. They are able to make use of the atmospheric nitrogen and change it into
nitrogenous compounds.
• The nitrogen-fixing bacteria are thus unique in tapping a source of nitrogen not
available to most other plants. This process of nitrogen transformation is called
nitrogen fixation

14. Nitrogen-fixing Bacteria
Azotobacter and Beijerinckia indica (aerobic
forms) and Clostridium (anaerobic) live free
in the soil
Rhizobium bacteria, living in root nodules of
leguminous plant symbiotically, helps in fixing
atmospheric nitrogen making rhizosphere
Rhizobium leguminosarum (syn. Bacillus
radicicola) is another nitrogen-fixing
bacterium

15. Azotobacter and Beijerinckia indica(aerobic forms)
and Clostridium (anaerobic) live free in the soil
• They take gaseous nitrogen from the air present
between the soil particles.
• The nitrogen combines with other elements forming
organic nitrogenous compounds.
• These compounds are assimilated by the bacteria.

16. Rhizobium leguminosarum (syn.
Bacillus radicicola) is another
nitrogen-fixing bacterium• It lives in the roots of such plants as Pea, Bean, and
others. All these belong to the Pea family
(Leguminoseae). Besides the legumes, the nodules
are found on the roots of Casuarina, species of
Coriaria and a few others.
• The symbiont in non- leguminous plants is a member
of Plasmodiophorales. The presence of bacteria in
the roots causes the formation of little nodules. In
Pavetta indica the bacterial nodules are formed on
the leaves.

17. Production of Organic Manure:
• Saprophytic bacteria help in breaking of
complex organic substance to simpler forms.
Thus, in this process, they help to convert
farm refuse, dung and other wastes to
manure.

18. Preparation of ensilage
• Ensilage is preserved cattle fodder prepared
by packing fresh chopped fodder sprinkled
with molasses.
• Fermentation activity of bacteria produces
lactic acid that acts as preservative in ensilage.

19. Biopesticides
• Bacteria acts as bio-pesticides to kill organisms causing
diseases to crops and aid in higher yield.
• Example: Bacillus Thuringiensis is one example of pesticides
to kill pests. Some species of Bacillus, Pseudomonas act as
anti-fungals.
• These bacteria are such that when applied, they kill only the
disease causing pests and insects.
• But they do not harm the plant or farmer because they are
specifically harmful to pests.
• Further, they are not harmful to the soil unlike chemical
fertilizers. Chemical fertilizers pollute the soil, air and water
around. But use of bio-pesticides avoids the problem. Further,
they are less expensive

20. Pest control
• Bacteria can also be used in the place
of pesticides in biological pest control.
• This commonly uses Bacillus thuringiensis (also called
BT), a Gram-positive, soil-dwelling bacterium.
• This bacterium is used as
a Lepidopteran-specific insecticide under trade
names such as Dipel and Thuricide.
• Because of their specificity, these pesticides are
regarded as environmentally friendly, with little
effect on humans, wildlife, pollinators, or
other beneficial insects

21. Biofertilizer
When bacteria like Blue-green Algae are left into agriculture soil, they fix
natural manure in form of nitrogen from air for better growth and yield of
crops.
Also, when a crop is harvested, the plant remains are allowed to degrade
in the soil.
Under rainfall, this waste material is acted on by bacteria to
decompose it.
This organic material acts to increase water retention capacity of the soil.
Further, the organic waste acts as natural manure and gives essential
nutrients to the crops.

22. Crop rotation
• Farmers cannot grow the same crop year after year, if they do so, the yield of crops
and also subsequent crops are affected by pests and diseases.
• To avoid this the farmers opt for crop rotation. This crop rotation is done by
alternating crops with a leguminous crop.
• For example; a farmer growing cotton this year will opt for leguminous crop like
groundnut or peanut the next year.
• This not only destroys the pests of previous crop but also builds fertility. This rise
in fertility due to leguminous crop is due to the prescence of symbiotic bacteria in
the roots.
• The Rhizobium is an example of such bacteria. This bacteria resides in the nodes of
the roots of leguminous plants and helps absorb nitrogen from air and fix it in the
roots. In turn, these bacteria extract nutrients from the plant(symbiosis).
• Thus, bacteria helps the plant and also builds fertility in the soil

23. Production of fuel
• Bacteria, while converting animal dung and
other organic wastes to manure, help in
production of fuel that is a must in gobar gas
plant.
• Many microorganisms affect anaerobic
digestion, including acetic acid-forming
bacteria (acetogens) and methane-forming
archaea (methanogens). These organisms
promote a number of biochemical processes
in converting the biomass to biogas. Acetate
and H2 to methane and co2

24. Against pollution

25. Bioremediation
• Bacteria can be used to
remove pollutants from contaminated water,
soil and subsurface material.
• During the Mega Borg Oil Spill, for example,
100 pounds of bacteria were sprayed over an
acre of the oil slick to break down
the hydrocarbons present into more
benign by-products

26. Plastic degradation
• The microbial species identified
from degrading polythene bags
and plastic cups were:-Bacillus
subtilis,Aspergillus niger, Aspergillus
nidulance, Aspergillus flavus, Aspergillus
glaucus, Penicillum species, Pseudomonas sp.,

27. Disposal of sewage
• Bacteria help in disposal of sewage by
decomposing it and thus, help in
environmental sanitation.

28. Zoogleal film— zoogleal ramigera

29. Role of bacteria in industry
• Dairy industry
• Production of organic compounds
• Fermentation
• Food processing
• Sterilization
• Tanning of hides
• Production of Indigo
• Fibre retting
• Curing of tobacco and tea
• Waste materials used

30. •Man has utilised the activities
of bacteria for various
industrial processes—benefit
of mankind

31. Dairy Industry
• Bacteria such as Streptococcus lactis convert milk sugar lactose into lactic
acid that coagulates casein (milk protein).
• Then, milk is converted into curd, yoghurt, cheese etc needed for the
industry.
• The butter and cheese industries entirely depend upon the activities of
the lactic acid bacteria.
• The souring and curding of milk by lactic acid bacteria is another common
example of application in everyday life.
• It takes place in two steps. In the first step the lactose sugar of milk is
fermented into glucose by an enzyme lactase secreted by the lactic acid
bacteria.
• In the second step there is transformation of glucose into lactic acid. The
latter sours the milk and coagulates the milk proteins (casein) forming
curds and whey

32. Production of organic compounds: fermentation
• Fermentation (breakdown of carbohydrate in absence of oxygen) action of
various bacteria produces organic compounds like lactic acid
(by Lactobacillus), acetic acid (by Acetobacter aceti), acetone
(by Clostridium acetabutylicum) etc.
• Anaerobic sugar fermentation reactions by various bacteria produce
different end products. The production of ethanol by yeasts has been
exploited by the brewing industry for thousands of years and is used for
fuel production.
• Other bacterial products and reactions have been
discovered in organisms from extreme
environments. There is considerable interest in the
enzymes isolated from thermophilic bacteria, in
which reactions may be carried out at higher rates
owing to the higher temperatures at which they can
occur.

33. Various organic compounds-uses
• (i) Lactic acid:
• It is useful in tanning industries.
• (ii) Citric acid:
• It is used to give aroma and flavour to beverages, sweets and other foodstuffs.
• (iii) Acetic acid and vinegar:
• Specific bacteria carry out the oxidation of alcohol to acetic acid in the production of vinegar
• (iii) Vitamins:
• Vitamin B is the product of fermentation of sugars and starch by Clostridium
acetobutilicum. The vitamins are used in medicinal preparations.
• (iv) Butyl alcohol: ABE FERMENTAION
• Butyl alcohol, acetone and ethyl alcohol, isopropanol are produced in one fermentation
operation with Clostridium beijerinckii is allowed to act on com starch. These products are
important commercial solvents-
• (v) Acetone:
• It is an important ingredient of explosives and is also used in the manufacture of
photographic films

35. Brewing industry
• Brettanomyces,
Lactobacillus and Pediococcus are kind of the
“Three Stooges” of sour beer production

36. Food processing
• Sourdough bread is made to rise
by fermentation, with a leaven that consists of
bacteria, often combined with wild yeast
enzymes.
• The milk-souring bacterial genus Lactobacillus is
used to make yoghurt and cheese.
• Bacteria are used, too, to form organic acids
in pickles and vinegar

37. Sterilization
• This is a process to eradicate microbial
contamination from finished products.
• Few bacteria are used as biological indicators
for sterilization validation. These bacteria are
available commercially as strips containing
spores.
• B acillus atrophaeus

38. Tanning of hides and skins
• The action of bacteria is useful in the
conversion of hides and skins to leather during
the tanning process.
• Staphylococcus spp., Micrococcus spp.,
Corynebacterium sp

39. .
Sponge preparation
• preparing sponges also involve the use of
bacteria
• E.coli recombinant cells

40. Use in other productions
• Vitamins
• antibiotics
• Vaccines
• Amino acids
• Enzymes

41. Fibre retting
• Bacteria such as Clostridium butyricum are used to separate
fibres of jute, hemp and flax in the process of retting.
• The plants are immersed in water and when they swell,
inoculated with bacteria which hydrolyze pectic substances
of the cell walls and separate the fibres. Alternatively, the
plants are spread out on the ground, where they become
wetted by dew and ret naturally. These separated fibres are
used to make ropes, sacks etc
• Pseudomonas help in fibre retting i.e. separation of stem and
leaf fibre of plants from other softer tissue.
• The production of linen is impossible without bacterial
activity. The tough fibres, which are left behind, are
separated. These fibres are spun and woven into linen cloth,
ropes, etc.

42. Curing of tobacco and tea
• Bacteria are useful in the curing or ripening of tobacco leaves.
Mirococcus and Bacillus Megatherium are used in the curing
of tea, tobacco, beans of coffee and cocoa to cure off their
bitternes
• The leaves of tea and tobacco, beans of coffee and coca are
cured off their bitterness with the help of action of certain
bacteria such as Bacillus megatherium
• The cocoa beans are white in colour and quite bitter in taste.
The bacteria digest the bitter coverings of seeds and give the
taste

43. Production of Indigo
• micro-organisms are aromatic hydrocarbon
degrading bacteria such as
naphthalene-degrading Pseudomonas putida
are needed for production of indigo

44. Waste uses
• Many saprophytic bacteria in their metabolic
activities excrete waste products of
great commercial importance

45. Role of bacteria in medicine
• Source of Antibiotics:
• Preparation of vitamins
• Preparation of Serums and Vaccines:

46. Production of antibiotics
• Number of anti bacterial and anti fungal antibiotics
such as Hamycin, streptomycin, aureomycin,
terramycin Polymyxin, Trichomycin etc are obtained
from mycelia bacteria or filamentous actinomycetes
(like Streptomyces). Similarly, Bacillus is used for
production of antibiotics such as Bacitracin,
Gramicidin etc
• The milder antibiotics of bacterial origin are
tyrothricin, subtilin, polymyxin B, and bacitracin.
Bacillius subtilisis the source of subtilin.
• Bacitracin is obtained from a stain very much like B.
Subtilis.

47. Production of vitamins
• Different kinds of vitamins are produced from
bacteria like Riboflavin from Clostridium
butylicum,
• Vitamin B12 from Bacillus megatherium and
Vitamin K and B-complex from Escherichia
coli.

48. Preparation of Serums and
Vaccines
• These are substances which are used to develop immunity to
various diseases in man.
• Serums are used in advance as a therapeutic measure. They
are also used when a person actually suffers from a disease.
Diphtheria, lockjaw, pneumonia, etc. are the diseases in
which the serums are effective.
• Vaccines are commonly used to make people immune to
diseases like typhoid, small-pox, cholera, scarlet fever, etc. In
the preparation of serums, small doses of bacterial toxins
(poisons) are injected into the blood of animals such as
horses.
• To combat or neutralize the bacterial poisons, the body of the
animal produces antibodies

49. Biotechnology
• Biotechnology involves the use of microorganisms including
bacteria and fungi in the manufacturing and services
industries.
• These include chemical manufacturing such
as ethanol, acetone, organic acid, enzymes, and perfumes.
Bacteria are important in the production of many dietary
supplements and pharmaceuticals.
• For example, Escherichia coli is used for commercial
preparation of riboflavin and vitamin K.
• E. coli is also used to produce D-amino acids such as
D-p-hydroxyphenylglycine, an important intermediate for
synthesis of the antibiotic amoxicillin

50. Genetic engineering
• Genetic engineering is the manipulation of genes.
• It is also called recombinant DNA technology.
• In genetic engineering, pieces of DNA (genes) are introduced
into a host by a variety of techniques, one of the earliest
being the use of a virus vector. The foreign DNA becomes a
permanent feature of the host, and is replicated and passed
on to daughter cells along with the rest of its DNA.
• Bacterial cells are transformed and used in production of
commercially important products. Examples include
production of human insulin(used to treat diabetes)
and human growth hormone (somatotrophin) used to treat
pituitary dwarfism)

51. Digestion
• Bacteria living in the gut of cattle, horses and other
herbivores, for example Ruminococcus spp., help
digest cellulose by secreting the enzyme cellulase.
• This is how herbivores are able get the energy they need from
grass and other plants
• Also, Escherichia coli, part of the intestinal microbiota of
humans and other animals, converts consumed food
into vitamin K2
. This is absorbed in the colon and, in animal
models, is sufficient to meet their daily requirement of the
vitamin

52. Harmful effects of bacteria
Though bacteria plays important role in
agriculture, industries and natural
sanitation etc, it has the following
harmful effects:

53. Harmful effects of bacteria
• Food poisoning
• Food spoiling
• Damaging of domestic articles
• Desulphurifaction
• Cause of Disease
• Denitrification

54. Food spoilage
• Saprophytic bacteria always not only help in
decomposition of dead matters, but they also
cause the rotting of vegetables, fruits, meat,
bread etc

55. Food poisoning
• acteria like Staphylococcus aureus cause food
poisoning and cause people diarrhea and
vomiting.

56. Damaging of domestic articles
• Spirochete cytophaga deteriorates cotton,
leather and wooden articles.

57. Denitrification
Bacteria such as Thiobacillus and Microbacillus
convert nitrate of the soil to the gaseous
nitrogen.
This hampers plants very much.

58. Desulphurication
• Bacteria such as Desulfovibrio convert soil
sulphates into hydrogen sulphide.
• bacterial oxidation of sulfide materials results
in the undesirable formation of acid mine
drainage, the same reaction has been put to
use for microbial leaching of copper, uranium,
and other valuable metals from low-grade
sulfide-containing ores

59. Disease
• It is known that over 90% of human diseases
and over 10% of plant diseases are caused by
bacteria.
• Many parasitic bacteria are the causative
agents of bacterial diseases. They cause
diseases of our economic plants,
domesticated animals and man.
• There are more than 170 species of bacteria
which cause plant diseases. Usually they are
rod-like and non-spore forming. Many of them
have flagella

61. List of Diseases in man and animals

62. Bacterial diseases in plants
• i) Wilt diseases caused by blocking of the vessels of host plant
by masses of bacteria. The common example of this category
are the wilt diseases of potato, cucumber, water melon and
eggplant- Erwinia tracheiphila,
• (ii) Crown gall and Hairy root diseases. These are due to
overgrowth or hyperplasia. The crown gall of beets and hairy
root of apple are the examples- Agrobacterium tumefaciens
• (iii) Narcotic blights, leaf spots and rots caused by killing of
parenchyma cells. Fire blight of apple, and pear and soft rot of
carrot and turnip are the common examples- Xanthomonas
axonopodis pv. manihotis in casava