By

G.PRANAVATHIYANI

B.Sc BIO-INFORMATICS

"Microbes can do anything they

want, wherever they want - without

microbes, humans wouldn't be

alive"

Microbes include a diverse group of

simple life-forms such as

Protozoans,

Algae,

Molds,

Bacteria, and

Viruses.

Microorganisms live in all parts of the

biosphere where there is liquid water,

including soil, hot springs, on the

ocean floor, high in the atmosphere

and deep inside rocks within the

Earth's crust.

Scientific study of these

microorganisms is termed as

“MICROBIOLOGY”.

It is concerned with the structure,

function, and classification of these

organisms and with ways of

controlling and using their

activities.

Though pathogenic microbes are

harmful, as they invade and grow

within other organisms, causing

diseases that kill humans, other

animals and plants, they provide

many welfare to the human

society.

In addition, means of

channeling the activities of

various microorganisms to

benefit human lives have

been discovered. Molds, for

example, produce antibiotics,

notably penicillin.

MICROBES

• Industrial Products

• Food & Dairy Industries

• Agriculture

• Medicine

• Genetic Engineering

• Biotechnology

Decomposition (or rotting) is the

process by which organic material is

broken down into simpler forms of

matter.

One can differentiate abiotic from

biotic decomposition (biodegradation).

The former means "degradation of a

substance by chemical or physical

processes, eg: hydrolysis. The latter one

means "the metabolic breakdown of

materials into simpler components by

living organisms", typically by

microorganisms.

Various sciences study the

decomposition of bodies under the

general rubric of forensics because the

usual motive for such studies is to

determine the time and cause of death

for legal purposes.

Microbes are critical to the processes of

decomposition required to cycle

nitrogen and other elements back to the

natural world.

Methanogenesis:

Methanogenesis or biomethanation is

the formation of methane by microbes

known as methanogens. The

production of methane is an

important and widespread form of

microbial metabolism. In most

environments, it is the final step in the

decomposition of biomass.

MICROBES IN PRODUCTION OF BIOGAS:

Biogas is a mixture of gases (containing

predominantly methane) produced by

the microbes and which

may be used as fuel.

Certain bacteria, which grow

anaerobically on cellulosic material,

produce large amount of methane along

with CO2 and H2. These bacteria are

collectively called methanogens, and one

such common bacterium is

Methanobacterium.

-These bacteria are found in the anaerobic sludge

during sewage treatment. These bacteria are also

present in the rumen (a part of stomach) of cattle.

-A lot of cellulosic material present in the food of

cattle is also present in the rumen. In rumen, these

bacteria help in the breakdown of cellulose and play

an important role in the nutrition of cattle.

-Thus, the excreta (dung) of cattle, commonly called

gobar, is rich in these bacteria. Dung can be used for

generation of biogas, commonly called gobar gas.

The biogas plant consists of a

concrete tank (10-15 feet deep) in

which bio-wastes are collected and

slurry of dung is fed.

A floating cover is placed over the

slurry, which keeps on rising as the

gas is produced in the tank due to

the microbial activity.

The biogas plant has an outlet,

which is connected to a pipe to

supply biogas to nearby houses.

The spent slurry is removed through another outlet and

may be used as fertilizer. Cattle dung is available in

large quantities in rural areas where cattle are used for

a variety of purposes.

So biogas plants are more after build in rural areas. The

biogas thus produced is used for cooking and lighting.

Stages in anaerobic digestion:

Anaerobic digestion is a series of processes in

which microorganisms break down biodegradable

material in the absence of oxygen. It is used for

industrial or domestic purposes to manage waste

and/or to release energy.

The solid, fibrous

component of the

digested material can

be used as a soil

conditioner to increase

the organic content of

soils.

It can be used as a

manure to the plants.

Biogas Appliances:

Biogas is a lean gas that can, in principle,

be used like other fuel gas for household

and

industrial purposes, especially for:

· Gas cookers/stoves

· Biogas lamps

· Radiant heaters

· Incubators

· Refrigerators

· Engines

Using anaerobic digestion technologies can help to

reduce the emission of greenhouse gases in a number

of key ways:

Replacement of fossil fuels.

Reducing or eliminating the energy footprint of

waste treatment plants.

Reducing methane emission from landfills.

Displacing industrially produced chemical fertilizers.

Reducing vehicle movements.

Reducing electrical grid transportation losses.

Generation of Oxygen in the

Atmosphere.

Recycling nutrients stored in

organic matter to an

inorganic form.

Fix nitrogen from the

Atmosphere into a Useable

Form.

Give Plant Roots Access to

Nutrients in the Soil.

Allow Herbivores to

Consume Poor Quality Food.

Involve in BIOGEOCHEMICAL

cycles such as N2 ,O2,K,S

cycles.

Degradation of oil spills.

Wastewater treatment uses

microbes to decompose

organic matter in sewage.

Biofertilizers- are the

organisms that enrich the

nutrient quality of the soil.

Human digestion:

Microorganisms can form an endosymbiotic

relationship with other, larger organisms. For

example, the bacteria that live within the

human digestive system contribute to gut

immunity, synthesize vitamins such as folic

acid and biotin, and ferment complex

indigestible carbohydrates.

Recent researches

in

”MICROBES”

May 23, 2011:

Using bacteria to generate

energy is a significant step

closer following a

breakthrough discovery by

scientists at the University of

East Anglia (UEA).This can

be used to generate power.

March 1, 2012:

“The research provides

some of the first tangible

details about the

fascinating symbiotic

relationship between

leafcutter ants, fungi and

bacteria”.