Bacteria have widespread economic importance through their use in various industrial and agricultural processes. They are used to produce dairy products like curd, yogurt and cheese through fermentation. Many industrial products are also produced with bacterial action such as vinegar, citric acid, vitamin B12 and antibiotics. Bacteria play an important environmental role through nitrogen fixation, nitrogen cycling, sewage treatment, biogas production and as decomposers. However, some bacteria can also be harmful by causing food spoilage, food poisoning and diseases in plants and humans.

1. ECONOMIC
IMPORTANT OF
BACTERIA
B. AKASH KUMAR
BP221523

2. What is the Economic Importance of Bacteria?
 Bacteria have widespread economic importance as they are used in
various processes, as discussed below. The Economic Importance of
Bacteria examples will help understand the significance of bacteria.

3. Dairy products
Quite a few genera of bacteria are used in food preparation, directly or indirectly.
a. Formation of Curd: Milk is converted into curd by bacterial action. The milk’s lactose is converted into lactic
acid, which gives the characteristic sour taste of the curd. Lactic acid bacteria (LAB) like Lactobacillus are
added to milk. Indian curd is prepared by inoculating milk with Lactobacillus acidophilus.
b. Yoghurt preparation: It is produced by curdling milk with Streptococcus thermophilus and Lactobacillus
bulgaricus.
c. Cheese production starts with milk coagulated with lactic acid bacteria and the curd formed is filtered to
separate the whey. The solid mass is then ripened with the growth of mould that develops flavour in
it. Propionibacterium shermanii is used to make cheese.

4. In Industry
A large number of products are obtained due to bacterial activity,
directly proportional to the economic importance of Bacteria.

5. Product Bacteria name
Vinegar or Acetic acid Acetobacter aceti
Citric acid
Bacillus licheniformis and Corynebacterium
species
Vitamin [Math Processing Error]B12 Pseudomonas denitrificans
Retting of Fibres like jute, etc. Clostridium butyricum
The curing and ripening of tea and tobacco
leave
Bacillus megaterium
Certain species of bacteria are used in The
Preparation of leather from hides and skins of
animals.
Species of Staphylococcus, Micrococcus,
Corynebacterium, Streptococcus,
Enterococcus, Bacillus are used. Besides
these, Aerococcus viridans, Pseudomonas
Vulgaris, Lactobacillus jensenii are also used.

6. In Medicine
Some bacteria have been exploited to produce antibiotics. Antibiotics like Terramycin,
Streptomycin, Tetracycline, Aureomycin, Neomycin are obtained from different bacterial
species.
Vaccines
 Several vaccines have been developed from either killed or attenuated (living but
multiplying at low rates) bacteria. For example, tuberculosis vaccine, whooping cough
vaccine, plague vaccine, DTP (Diphtheria, Tetanus, Pertussis) vaccine, pneumonia
vaccine are all prepared with the help of bacteria.

7. Antibiotic Bacteria
Chloromycetin Streptomyces venezuelae
Erythromycin Streptomyces erythreus
Streptomycin Streptomyces griseus
Oxytetracycline /Terramycin Streptomyces aureofaciens
Bacitracin Bacillus licheniformis
Neomycin Streptomyces fradiae
Terramycin Streptomyces rimosus
Aureomycin Streptomyces aureofaciens

8. In Maintenance of Environmental Balance and Agriculture
 Bacteria act as decomposers. They make the nutrient available for plants. Specific genera of
bacteria are used as biocontrol agents in agriculture. Bacillus thuringiensis (Bt) yields protein-
based toxins used to kill insects.
Nitrogen fixation and soil fertility
 Certain bacteria are helpful in the fixation of atmospheric nitrogen. Azotobacter and Clostridium
are present in the soil and help in nitrogen fixation. Species of Rhizobium bacteria are present in the
root nodules of leguminous plants, and they increase the soil’s nitrogen content by fixing up
atmospheric nitrogen. The process is known as symbiotic nitrogen fixation.
 Several cyanobacteria also help in nitrogen fixation. Nostoc, Anabaena, etc., possess heterocysts
with nitrogenase enzymes and fix atmospheric nitrogen in symbiotic conditions. Nostoc is
associated with the coralloid roots of Cycas and helps in this process. Anabaena azollae is
associated with water fern, Azolla, and helps in nitrogen fixation in paddy fields.

9. Role in Nitrogen Cycling
Nitrification is one of the most critical steps in the nitrogen cycle, performed by nitrifying bacteria.
Nitrifying bacteria are chemolithotrophic organisms that include the genera Nitrosomonas,
Nitrococcus, Nitrobacter, Nitrobacillus, etc. These bacteria get their energy by the oxidation of
inorganic nitrogen compounds.
The denitrifying bacteria, like Pseudomonas denitrificans, Thiobacillus denitrificans, transform the
nitrates to free atmospheric nitrogen.
Sewage Treatment
Sewage is agricultural and domestic waste products that pollute the water. The treatment to
remove such waste is partially chemical, biological treatment.
a. Secondary treatment is the biological treatment, which reduces the BOD significantly. Aerobic
bacteria are used in this process.
b. Tertiary treatment is done once there is a reduction of BOD in the settling tank. Mainly
Methanogens grow anaerobically and produce biogas.

10. Biogas Production
Biogas is a standard domestic and industrial fuel, which contains [Math Processing
Error]50−60% methane, [Math Processing Error]30−40% carbon dioxide, [Math Processing
Error]0−3% Sulphur compounds, and traces of other gases like hydrogen CO, nitrogen, etc.
1. In a biogas digester, cattle dung is used to obtain gas (gobar gas) in the following steps:
a. Hydrolysis is the initial step that needs anaerobic bacteria like Clostridium, Pseudomonas,
etc.
b. Acidogenesis is the second step, in which the facultatively anaerobic, acidogenic bacteria
and obligate anaerobic organisms help convert the simple organic material into acids like
formic acid, acetic acid, etc.
c. Methanogenesis is the last step, in which anaerobic Methanogenic bacteria
like Methanobacterium, Methanococcus, etc., convert organic acids into Methane.

11. Harmful effects of Bacteria
Though bacteria plays important role in agriculture, industries and natural sanitation etc, it has the following
harmful effects:
◦ Food Spoiling: Saprophytic bacteria always not only help in decomposition of dead matters, but they also cause
the rotting of vegetables, fruits, meat, bread etc.
◦ Food Poisoning: Bacteria like Staphylococcus aureus cause food poisoning and cause people diarrhea and
vomiting.
◦ Damaging of domestic articles: Spirochete cytophaga deteriorates cotton, leather and wooden articles.
◦ Denitrification: Bacteria such as Thiobacillus and Microbacillusconvert nitrate of the soil to the gaseous nitrogen.
This hampers plants very much.
◦ Desulphurication: Bacteria such as Desulfovibrio convert soil sulphates into hydrogen sulphide.
◦ Cause of Diseases: It is known that over 90% of human diseases and over 10% of plant diseases are caused by
bacteria.

12. THANK YOU