SCOPE AND RELEVANCE OF MICROBIOLOGY

Microbiology has both basic and applied aspects. The basic aspects are concerned with the biology of microorganisms themselves.

The applied aspects are concerned with practical problems such as disease, water, and wastewater treatment, food spoilage and food production, and industrial uses of microbes.

It is important to note that the basic and applied aspects of microbiology are intertwined. Basic research is often conducted in applied fields, and applications often arise out of basic research.

A discussion of some of the major fields of microbiology and the occupations within them follows.

1. Medical microbiology:

• Although pathogenic microbes are the minority, they garner considerable interest.

• One of the most active and important fields in microbiology is medical microbiology,

• Medical microbiology deals with diseases of humans and animals.

• Medical microbiologists identify the agents causing infectious diseases and plan measures for their control and elimination. Frequently they are involved in tracking down new, unidentified pathogens. These microbiologists also study the ways in which microorganisms cause disease.

2. Public health microbiology:

• Public health microbiology is concerned with the control and spread of such communicable diseases.

• Public health microbiologists and epidemiologists monitor the amount of disease in populations.

• Based on their observations, they can detect outbreaks and developing epidemics, and implement appropriate control measures in response.

• They also conduct surveillance for new diseases as well as bioterrorism events.

• Those public health microbiologists working for local governments monitor community food establishments and water supplies in an attempt to keep them safe and free from infectious disease agents.

3. Immunology:

• Immunology is concerned with how the immune system protects the body from pathogens and the response of infectious agents.

• It is one of the fastest-growing areas in science. Much of the growth began with the discovery of HIV, which specifically targets cells of the immune system.

• Immunology also deals with health problems such as the nature and treatment of allergies and autoimmune diseases such as rheumatoid arthritis.

4. Agricultural microbiology:

• Agricultural microbiology is concerned with the impact of microorganisms on agriculture.

• Microbes such as nitrogen-fixing bacteria play critical roles in the nitrogen cycle and affect soil fertility.

• Other microbes live in the digestive tracts of ruminants such as cattle and break down the plant materials these animals ingest.

• There are also plant and animal pathogens that can have significant economic impacts if not controlled.

• Agricultural microbiologists work on methods to increase soil fertility and crop yields, study rumen microorganisms in order to increase meat and milk production, and try to combat plant and animal diseases.

• Currently, many agricultural microbiologists are studying the use of bacterial and viral insect pathogens as substitutes for chemical pesticides.

5. Microbial ecology:

• Microbial ecology is concerned with the relationships between microorganisms and the components of their living and non-living habitats.

• Microbial ecologists study the global and local contributions of microorganisms to the carbon, nitrogen, and sulphur cycles, including the role of microbes in both the production and removal of greenhouse gases such as carbon dioxide and methane.

• The study of pollution effects on microorganisms also is important because of the impact these organisms have on the environment.

• Microbial ecologists are employing microorganisms in bioremediation to reduce pollution.

• The study of the microbes normally associated with the human body has become a new frontier in microbial ecology.

6. Food and dairy microbiology:

• Numerous foods are made using microorganisms.

• On the other hand, some microbes cause food spoilage or are pathogens spread through food.

• Scientists working in food and dairy microbiology continue to explore the use of microbes in food production.

• They also work to prevent microbial spoilage of food and the transmission of food-borne diseases.

• There is also considerable research on the use of microorganisms themselves as a nutrient source for livestock and humans.

7. Industrial microbiology:

• In 1929 Alexander Fleming discovered that the fungus Penicillium produced what he called penicillin, the first antibiotic that could successfully control bacterial infections.

• Although it took World War II for scientists to learn how to mass-produce it, scientists soon found other microorganisms capable of producing additional antibiotics as well as compounds such as citric acid, vitamin B 12, and monosodium glutamate (MSG).

• Today, industrial microbiologists use microorganisms to make products such as antibiotics, vaccines, steroids, alcohols, and other solvents, vitamins, amino acids, and enzymes.

• Industrial microbiologists identify microbes of use to industry. They also utilize techniques to improve production by microbes and devise systems for culturing them and isolating the products they make.

8. Microbial Physiology and Biochemistry:

• Microbes are metabolically diverse and can employ a wide variety of energy sources, including organic matter, inorganic molecules (e.g., H₂ and NH₃), and sunlight.

• Microbiologists working in microbial physiology and biochemistry study many aspects of the biology of microorganisms, including their metabolic capabilities.

• They may also study the synthesis of antibiotics and toxins, the ways in which microorganisms survive harsh environmental conditions, and the effects of chemical and physical agents on microbial growth and survival.

9. Microbial Genetics and Molecular Biology:

• Microbial genetics and molecular biology focus on the nature of genetic information and how it regulates the development and function of cells and organisms.

• The bacteria Escherichia coli and Bacillus subtilis, the yeast Saccharomyces cerevisiae (baker’s yeast), and bacterial viruses such as T4 and lambda continue to be important model organisms used to understand biological phenomena.

• Microbial geneticists also play a significant role in applied microbiology because they develop techniques that are useful in agricultural microbiology, industrial microbiology, food and dairy microbiology, and medicine.

• Because of the practical importance of microbes and their use as model organisms, the future of microbiology is bright.