MICROORGANISMS AROUND US

MICRO- ORGANISM are organism that is too small to be seen by the unaided eye, especially a single celled organism, such as bacteria.

Micro-organisms are tiny organisms which cannot be seen with the naked eye except with the aid of microscopes. The branch of biology which involves the study of organisms that are microscopic in sizes is called Microbiology.

Microbiology is a science that deals with the study of living organisms that cannot be seen with the naked eyes except with the use of an instrument called Microscope.

Such microscopic organisms are collectively reffered to as microorganisms, microbes, germs or several other terms, depending upon the purpose. They are commonly dreaded as disease- causing agent.

The major groups of microorganisms are bacteria, viruses, fungi, protozoa, algae and helminthes.

Various branches of microbiology includes: 

Bacteriology

 Virology

 Mycology

 Parasitology

 Phycology 

mmunology etc.

Although,most of micro - organism are unicellular some fungi and algae are multicellular. Here are the hint.

            Viruses.

Virus are obligate intracellular parasites that have either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) as their geno type (genetic material) and enclosed by a protein coat. It can only replicate in living cells and can only be seen through the aid of microscope.

Virus means poison. Viruses inhibit a non man's land between the living and the non living worlds, and possess characteristics of both.

Characteristics of virus

1. They are obligate intracellular parasites (can reproduce only inside a host cell).

2. They cannot be observed using a light microscope.

3. They have no internal cellular structure.

4. They contain either DNA or RNA, but not both.

5. They are incapable of metabolism.

Examples of viruses are:

Togavirus,

Adenovirus,

Picornavirus and

Coronavirus.

The techniques and method of growing microorganisms is known as CULTURE.

CULTURE IN VIRUES

Cultured bacteria and tissue cells are often used for growing virues. Fertilized hens' egg are also used. This is carried out by injecting the appropriate virus into the egg, where it starts multiplying. The virus sample may be inoculated into the chorioallantoic membrane, allantoic cavity and yolk sac

        Bacteria.

Bacteria are microorganisms that can easily be seen with light microscope. They occure in clusters or colonies. They have a nuclear material called DNA which spread through the cell.

Bacteria are easy to grow in a test-tubes and petric dishes of culture media. Since Bacteria can replicate and grow inside living cell

Types of bacteria.

Bacteria on the basis of their shape.

a. Cocci (singular: Coccus)

       They can be perfect shapes, but they also can exist as oval, bean shaped. They can associate to form chains as with *Streptococcus*, or grape like clusters (as with *Staphylococcus* cuboid shape (as with Sarcina), in pairs as in *Diplococcus* or singly as in *Monococcus*.

b. *Bacilli (singular: Bacillus)*

These are rod like shape or cylindrical (longer than wide) bacteria. These are bacteria that can cause Typhoid fever.

Examples are Echerichia coli, Salmonella SPP, Shingella SPP, Bacillus SPP etc.

c. *Vibro*

      These are bacteria that have comma shape. They can also be known as a rod that are gently curved. 

Example: Vibro Cholereae.

d. *Spirillum*

     These are bacteria that exist In rigid helical or corkscrewform.

Example: Azospirillum SPP.

e. *Spirocheates*

      They exist in form of a more flexible spiral form that resemble a spring.

Example: Borrelia burgdorferi, Treponema pallidum etc.

(Syphilis bacteria).

            AlGAE

Algae are microscopic green plants with the majority mainly found in aquatic environment.

Classes of Algae.

1. Euglenophyta (Euglenids) e.g Euglena. Euglena consist of characteristics that feature between plant and animal

2. Pyrrophyta (Dinoflagellates) e.g Gonyaulax.

3. Chrysophyta (Diatom) e.g Diatom.

4. Phaeophyta (brown algae) e.g Fucus, Laminaria, Sargassum.

5. Rhodophyta (red seaweed) e.g Gelidium, Polysiphonia, batrachospernum.

6. Chlorophyta (green algae) e.g  Volvox, Spirogyra, Chlamydomonas

It can also be cultured in test-tubes or petric dishes 

           *FUNGI*

Fungi are saprophytic or parasitic non green plants. The saprophytic fungi are beneficial while the parasitic fungi cause different types of diseases.

         PROTOZOA

These microorganisms are microscopic free living unicellular animals e.g Trypanosomes which cause trypanosomiasis  and plasmodium which causes malaria fever.