Importance of Microbiology:

 

The environment:

•  Microbes are responsible for the cycling of carbon, nitrogen phosphorus (geochemical cycles)

•  Maintain ecological balance on earth

•  They are found in association with plants in symbiotic relationships, maintain soil fertility and may also be used to clean up the environment of toxic compounds (bio-remediation).

•  Some are devasting plant pathogens, but others act as biological control agents against these diseases.

Medicine:

•  Disease causing ability of some microbes such as

•  Small Pox (Variola virus)

•  Cholera ( Vibrio cholera )

•  Malaria ( Plasmodium , protozoa) etc.

•  They have also provided us with the means of their control in the form of antibiotics and other medically important drugs.

Food:

•  Microorganisms have been used to produce food, from brewing and wine making, through cheese production and bread making, to manufacture of soy sauce.

•  Microbes are also responsible for food spoilage.

Biotechnology:

•  Commercial applications include the synthesis of acetone, organic acids, enzymes, alcohols and many drugs.

•  Genetic engineering – bacteria can produce important therapeutic substances such as insulin, human growth hormone, and interferon.

 

Research:

•  Because of their simple structure they are easier to study most life processes in simple unicellular organisms than in complex multicellular ones.

•  Millions of copies of the same single cell can be produced in large numbers very quickly and at low cost to give plenty of homogenous experimental material.

•  Because they reproduce very quickly, they are useful for studies involving the transfer of genetic information.

 

Brief history of microbiology

•  Robert Hook (1665) – reported that life's smallest structural units were ‘little boxes' or ‘cells'. This marked the beginning of cell theory – that all living things are composed of cells.

•  Van Leuwenhoek (1673) – discovered the ‘invisible' world of microorganisms ‘animalcules'.

•  Until second half of nineteenth century many believed that some forms of life could arise spontaneously from non-living matter – spontaneous generation.

•  Francesco Redi (1668) – Strong opponent of spontaneous generation. He demonstrated that maggots appear on decaying meat only when flies are able to lay eggs on the meat.

•  John Needham (1745) – claimed that microorganisms could arise spontaneously from heated nutrient broth.

•  Lazzaro Spallanzani (1765) – repeated Needhams experiments and suggested that Needham's results were due to microorganisms in the air entering the broth.

•  Rudolf Virchow (1858) – concept of biogenesis – living cells can arise only from preexisting cells.

•  Louis Pasteur (1822-1895) – Pasteur's experiments on swan shaped necks resolved the controversy of spontaneous generation. His discoveries led to the development of aseptic techniques used in the laboratory and medical procedure to prevent contamination by microorganisms that are in the air.