Introduction to scope of mirobiology << Back
Introduction to scope of microbiology
Definition: It is the study of living organisms of microscopic size, that include essentially bacteria, fungi, algae, protozoa and the infectious agents viruses.
The Discovery of Microorganisms
Roman philosopher Lucretius (about 98–55 B.C.) and the physician Girolamo Fracastoro (1478–1553) recommended that infection was caused by invisible living creatures. The first person to examine and explain microorganisms was the part-time microscopist Antony van Leeuwenhoek (1632–1723) of Holland. In 1673 Leeuwenhoek sent detailed findings to Royal Society of London. He called such minute organisms as animalcules.It is clear from that he observe both bacteria and protozoa. some important events that leads to the discovery of microbiology is summarized as follows.
The arguments over Spontaneous Generation
Statement of spontaneous generation: living organisms could develop from nonliving matter. This outlook finally was confront by the Francesco Redi (1626–1697), who carried out a by a series of experiments on decaying meat and its capability to make maggots spontaneously. He placed meat in three containers. One flask was uncovered, a second flask was covered with paper, and the third flask was covered with a fine gauze that would exclude flies. Flies laid their eggs on the exposed meat and maggots developed. In other two container maggots were not produces. On gauze covered container maggots developed on the gauze. In 1748, John boiled mutton broth and then tightly close the flasks. In due course many of the flasks became hazy and contained microorganisms. He state that organic matter has a power to confer the properties of life on nonliving matter.
After few years Lazzaro Spallanzani done same experiment with some improved design. He seals glass flasks that contained water and seeds. If the sealed flasks were placed in boiling water for 45 minutes then no growth took place as long as the flask is sealed. He projected that air carried microorganisms to the nutritional medium, but also remark that the external air might be required for growth of animals already in the medium. The supporters of spontaneous generation theory supporters argued that heating the air in sealed flasks destroyed its ability to support life.
Finally Louis Pasteur settle the the matter once and for all. Pasteur designed a swan neck flask which has variety of curves at neck region, while maintaining the ends of the necks open to the atmosphere. Pasteur then boiled the nutrient medium for a some minutes and then allowed it to cool. No growth took place even though the contents of the flasks were uncovered to the air. He explains that no growth occurred because dust and germs had been entrapped on the walls of the curved necks. If necks is not swan shaped or they were broken, growth occurs. In this way the controversy around the spontaneous germination theory was resolved
Swan neck flask
Broadly accepted fields of microbiology
The Scope and application of Microbiology
Microorganisms were the primary living organisms on our earth. They were omni present. They are more plentiful than any other kind of organism, and probably it represents the largest part from the earth's biomass. The whole ecosystem depends on their activities, and their activities influences the humans in many ways. Hence currently microbiology is a large area with many different specialization; it has a great impact on fields such as diagnostics, medicine, agricultural and food chemistry, ecology, genetics, molecular biology and biochemistry.
One can get the importance of microbiology in the twentieth century by analysing the award of nobel prize in physiology or medicine. More than 33 % of these were given to scientists working on microbiology aspect.
1) Medical microbiology: It deals with the diseases of human being developed due to harmful effects of microbial pathogens.
2)Public health microbiology: Here microbiologist tries to control the spread of communicable diseases in the society. Public health microbiologists often monitor community food establishments an water supplies to keep them safe and free from infectious diseases.
3) Agriculture microbiology: Microbiologist tries to fight against the plant diseases that affect the important food crops, develop techniques to improve the soil fertility and crop yields. Development of biofertilizers and biopesticides are the recent examples.
4) Microbial Ecology: It is closely related to agricultural microbiology. Microbial ecologist study the relationship between microorganism and their habitats. They are concerned with the contribution of microorganism and their habitats. It also concern with the effect of pollution on microbes.
5) Vaterinary microbiology: This discipline deals with the pathogen of domestic livestocks and poultry. They control the spread of such diseases. They have the scope of establishing such live stock units.
6) Food Microbiology: It deals with the food industry. Here microbiologist is responsible microbial aspects of the quality and control. They are responsible for maintain the hygienic environment in the production unit. Many products are there which are processed with the help of microorganism or they are fermentation product of microbial origin. In such units production microbiologist are required. Eg. Single cell protein, ensilage, cheese etc.
7) Dairy microbiology: This includes microbiology of cream, physical and chemical testing of milk and dairy products and microbiological and physical and chemical properties of raw milk used for processing pasteurised milk.
8) Aero microbiology: It deals with the study of atmospheric air and environment which includes pollutants as well as bacteria, bacterial spores, fungal spores and viruses etc.
9) Aquatic microbiology: It deals with the study of microorganisms in aquatic environments.
10) Water and waste water microbiology ( Sanitary microbiology) : It deals with the study related to treatment of drinking water supplies and sewage disposal.
11) Geo chemical microbiology: It deals with the applied areas such as extraction of metal from the ores. Such process is also called bioleaching.
12) Industrial microbiology: It concerned with the efficient use of microorganisms to produce economically important products and with the development of techniques used to prevent microbial destruction of economically important products formed by other ways. Pharmaceutical industries involving the microbial production of antibiotics , vitamins and aminoacids as well as microbial transformation of steroids. Production units for preparing vaccines and toxods. Production of therapeutics developed by recombinant DNA technology. Industries involved in the microbial production of organic acids and enzyme industries.
Microbes affects the many branches of science that includes medicine, agriculture, industry, ecology, genetics, biochemistry, molecular biology. At present and for the anticipated future, microbiologists will face several challenges to crack many of society problems including combating disease, environmental issues, and maintaining/improving the world’s food supply.
Question : 1 Which of the following is not considered a microorganism?
Question : 2 Which scientist is most responsible for finally laying the theory of spontaneous generation to rest?
Question : 3 The first person to demonstrate that bacteria resides in air was
Question : 4 Who demonstrated that open tubes of broth remained free of bacteria when air was free of dust?
Question : 5 The role of phagocytosis was discovered by
Question : 6 On which of the following Pasteur first conducted his experiments of fermentation
Question : 7 Which of the following is correct regarding Koch’s postulate?
Question : 8 Francisco Redi did experiments on maggots which proved
Question : 9 Identify the correct match of the name of the investigator with their contribution in the field of microbiology
Question : 10 The applied aspect of microbiology is
Question : 11 Public health microbiology deals with
Question : 12 Which of the following match is correct regarding the broadly accepted field of microbiology
Introduction and Scope of microbiology