《微生物生物学》课程书籍文献：《Microbiology》微生物学PDF电子书（Lansing M. Prescott - McGraw-Hill，Fifth Edition）.pdf_P26-P30

Prescott−Harley−Klein: Microbiology, Fifth Edition I. Introduction to Microbiology 1. The History and Scope of Microbiology © The McGraw−Hill Companies, 2002 problems in fields such as medical microbiology, food and dairy microbiology, and public health microbiology (basic research is also conducted in these fields). Because the various fields of microbiology are interrelated, an applied microbiologist must be familiar with basic microbiology. For example, a medical microbiologist must have a good understanding of microbial taxonomy, genetics, immunology, and physiology to identify and properly respond to the pathogen of concern. What are some of the current occupations of professional microbiologists? One of the most active and important is medical microbiology, which deals with the diseases of humans and animals. Medical microbiologists identify the agent causing an infectious disease and plan measures to eliminate it. Frequently they are involved in tracking down new, unidentified pathogens such as the agent that causes variant creutzfeldt-Jacob disease, the hantavirus, and the virus responsible for AIDS. These microbiologists also study the ways in which microorganisms cause disease. Legionnaires’ disease (pp. 901–2); Hantavirus pulmonary syndrome (p. 877); AIDS (pp. 878–84) Public health microbiology is closely related to medical microbiology. Public health microbiologists try to control the spread of communicable diseases. They often monitor community food establishments and water supplies in an attempt to keep them safe and free from infectious disease agents. 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; for example, techniques for the production and use of monoclonal antibodies have developed extremely rapidly. Immunology also deals with practical health problems such as the nature and treatment of allergies and autoimmune diseases like rheumatoid arthritis. Monoclonal antibodies and their uses (section 32.3 and Box 36.2) Many important areas of microbiology do not deal directly with human health and disease but certainly contribute to human welfare. Agricultural microbiology is concerned with the impact of microorganisms on agriculture. Agricultural microbiologists try to combat plant diseases that attack important food crops, work on methods to increase soil fertility and crop yields, and study the role of microorganisms living in the digestive tracts of ruminants such as cattle. Currently there is great interest in using bacterial and viral insect pathogens as substitutes for chemical pesticides. The field of microbial ecology is concerned with the relationships between microorganisms and their living and nonliving habitats. Microbial ecologists study the contributions of microorganisms to the carbon, nitrogen, and sulfur cycles in soil and in freshwater. 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 effects. Scientists working in food and dairy microbiology try to prevent microbial spoilage of food and the transmission of foodborne diseases such as botulism and salmonellosis (see chapter 39). They also use microorganisms to make foods such as cheeses, yogurts, pickles, and beer. In the future microorganisms themselves may become a more important nutrient source for livestock and humans. In industrial microbiology microorganisms are used to make products such as antibiotics, vaccines, steroids, alcohols and other solvents, vitamins, amino acids, and enzymes. Microorganisms can even leach valuable minerals from low-grade ores. Research on the biology of microorganisms occupies the time of many microbiologists and also has practical applications. Those working in microbial physiology and biochemistry study the synthesis of antibiotics and toxins, microbial energy production, the ways in which microorganisms survive harsh environmental conditions, microbial nitrogen fixation, the effects of chemical and physical agents on microbial growth and survival, and many other topics. 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 use of microorganisms has been very helpful in understanding gene function. Microbial geneticists play an important role in applied microbiology by producing new microbial strains that are more efficient in synthesizing useful products. Genetic techniques are used to test substances for their ability to cause cancer. More recently the field of genetic engineering (see chapter 14) has arisen from work in microbial genetics and molecular biology and will contribute substantially to microbiology, biology as a whole, and medicine. Engineered microorganisms are used to make hormones, antibiotics, vaccines, and other products (see chapter 42). New genes can be inserted into plants and animals; for example, it may be possible to give corn and wheat nitrogenfixation genes so they will not require nitrogen fertilizers. 1.7 The Future of Microbiology As the preceding sections have shown, microbiology has had a profound influence on society. What of the future? Science writer Bernard Dixon is very optimistic about microbiology’s future for two reasons. First, microbiology has a clearer mission than do many other scientific disciplines. Second, it is confident of its value because of its practical significance. Dixon notes that microbiology is required both to face the threat of new and reemerging human infectious diseases and to develop industrial technologies that are more efficient and environmentally friendly. What are some of the most promising areas for future microbiological research and their potential practical impacts? What kinds of challenges do microbiologists face? The following brief list should give some idea of what the future may hold: 1. New infectious diseases are continually arising and old diseases are once again becoming widespread and destructive. AIDS, hemorrhagic fevers, and tuberculosis are excellent examples of new and reemerging infectious diseases. Microbiologists will have to respond to these threats, many of them presently unknown. 2. Microbiologists must find ways to stop the spread of established infectious diseases. Increases in antibiotic resistance will be a continuing problem, particularly the spread of multiple drug resistance that can render a pathogen impervious to current medical treatment. 1.7 The Future of Microbiology 13

Prescott−Harley−Klein: Microbiology, Fifth Edition I. Introduction to Microbiology 1. The History and Scope of Microbiology © The McGraw−Hill Companies, 2002 Microbiologists have to create new drugs and find ways to slow or prevent the spread of drug resistance. New vaccines must be developed to protect against diseases such as AIDS. It will be necessary to use techniques in molecular biology and recombinant DNA technology to solve these problems. 3. Research is needed on the association between infectious agents and chronic diseases such as autoimmune and cardiovascular diseases. It may be that some of these chronic afflictions partly result from infections. 4. We are only now beginning to understand how pathogens interact with host cells and the ways in which diseases arise. There also is much to learn about how the host resists pathogen invasions. 5. Microorganisms are increasingly important in industry and environmental control, and we must learn how to use them in a variety of new ways. For example, microorganisms can (a) serve as sources of high-quality food and other practical products such as enzymes for industrial applications, (b) degrade pollutants and toxic wastes, and (c) be used as vectors to treat diseases and enhance agricultural productivity. There also is a continuing need to protect food and crops from microbial damage. 6. Microbial diversity is another area requiring considerable research. Indeed, it is estimated that less than 1% of the earth’s microbial population has been cultured. We must develop new isolation techniques and an adequate classification of microorganisms, one which includes those microbes that cannot be cultivated in the laboratory. Much work needs to be done on microorganisms living in extreme environments. The discovery of new microorganisms may well lead to further advances in industrial processes and enhanced environmental control. 7. Microbial communities often live in biofilms, and these biofilms are of profound importance in both medicine and microbial ecology. Research on biofilms is in its infancy; it will be many years before we more fully understand their nature and are able to use our knowledge in practical ways. In general, microbe-microbe interactions have not yet been extensively explored. 8. The genomes of many microorganisms already have been sequenced, and many more will be determined in the coming years. These sequences are ideal for learning how the genome is related to cell structure and what the minimum assortment of genes necessary for life is. Analysis of the genome and its activity will require continuing advances in the field of bioinformatics and the use of computers to investigate biological problems. 9. Further research on unusual microorganisms and microbial ecology will lead to a better understanding of the interactions between microorganisms and the inanimate world. Among other things, this understanding should enable us to more effectively control pollution. Similarly, it has become clear that microorganisms are essential partners with higher organisms in symbiotic relationships. Greater knowledge of symbiotic relationships can help improve our appreciation of the living world. It also will lead to improvements in the health of plants, livestock, and humans. 10. Because of their relative simplicity, microorganisms are excellent subjects for the study of a variety of fundamental questions in biology. For example, how do complex cellular structures develop and how do cells communicate with one another and respond to the environment? 11. Finally, microbiologists will be challenged to carefully assess the implications of new discoveries and technological developments. They will need to communicate a balanced view of both the positive and negative long-term impacts of these events on society. The future of microbiology is bright. The microbiologist René Dubos has summarized well the excitement and promise of microbiology: How extraordinary that, all over the world, microbiologists are now involved in activities as different as the study of gene structure, the control of disease, and the industrial processes based on the phenomenal ability of microorganisms to decompose and synthesize complex organic molecules. Microbiology is one of the most rewarding of professions because it gives its practitioners the opportunity to be in contact with all the other natural sciences and thus to contribute in many different ways to the betterment of human life. 14 Chapter 1The History and Scope of Microbiology Summary 1. Microbiology may be defined in terms of the size of the organisms studied and the techniques employed. 2. Antony van Leeuwenhoek was the first person to describe microorganisms. 3. Experiments by Redi and others disproved the theory of spontaneous generation in regard to larger organisms. 4. The spontaneous generation of microorganisms was disproved by Spallanzani, Pasteur, Tyndall, and others. 5. Support for the germ theory of disease came from the work of Bassi, Pasteur, Koch, and others. Lister provided indirect evidence with his development of antiseptic surgery. 6. Koch’s postulates and molecular Koch’s postulates are used to prove a direct relationship between a suspected pathogen and a disease. 7. Koch developed the techniques required to grow bacteria on solid media and to isolate pure cultures of pathogens. 8. Vaccines against anthrax and rabies were made by Pasteur; von Behring and Kitasato prepared antitoxins for diphtheria and tetanus. 9. Metchnikoff discovered some blood leukocytes could phagocytize and destroy bacterial pathogens. 10. Pasteur showed that fermentations were caused by microorganisms and that some microorganisms could live in the absence of oxygen

Prescott−Harley−Klein: Microbiology, Fifth Edition I. Introduction to Microbiology 1. The History and Scope of Microbiology © The McGraw−Hill Companies, 2002 Critical Thinking Questions 15 11. The role of microorganisms in carbon, nitrogen, and sulfur cycles was first studied by Winogradsky and Beijerinck. 12. Procaryotic cells differ from eucaryotic cells in lacking a membrane-delimited nucleus, and in other ways as well. 13. The Archaea are so different that many microbiologists divide organisms into three domains: Bacteria, Archaea, and Eucarya. 14. In the twentieth century microbiology has contributed greatly to the fields of biochemistry and genetics. It also has helped stimulate the rise of molecular biology. 15. There is a wide variety of fields in microbiology, and many have a great impact on society. These include the more applied disciplines such as medical, public health, industrial, food, and dairy microbiology. Microbial ecology, physiology, biochemistry, and genetics are examples of basic microbiological research fields. 16. Microbiologists will be faced with many exciting and important future challenges such as finding new ways to combat disease, reduce pollution, and feed the world’s population. Key Terms eucaryotic cell 11 hypothesis 8 Koch’s postulates 7 microbiology 2 microorganism 2 procaryotic cell 11 spontaneous generation 2 theory 8 Questions for Thought and Review 1. Why was the belief in spontaneous generation an obstacle to the development of microbiology as a scientific discipline? 2. Describe the major contributions of the following people to the development of microbiology: Leeuwenhoek, Spallanzani, Fracastoro, Pasteur, Tyndall, Cohn, Bassi, Lister, Koch, Chamberland, von Behring, Metchnikoff, Winogradsky, and Beijerinck. 3. Would microbiology have developed more slowly if Fannie Hesse had not suggested the use of agar? Give your reasoning. What is a pure culture? 4. Why do you think viruses are not included in the five-kingdom or three domain systems? 5. Why are microorganisms so useful to biologists as experimental models? 6. What do you think were the most important discoveries in the development of microbiology? Why? 7. List all the activities or businesses you can think of in your community that are directly dependent on microbiology. 8. Describe in your own words the scientific method. How does a theory differ from a hypothesis? Why is it important to have a control group? 9. What do you think are the five most important research areas to pursue in microbiology? Give reasons for your choices. Critical Thinking Questions 1. Consider the impact of microbes on the course of world history. History is full of examples of instances or circumstances under which one group of people lost a struggle against another. In fact, when examined more closely, the “losers” often had the misfortune of being exposed to, more susceptible to, or unable to cope with an infectious agent. Thus, weakened in physical strength or demoralized by the course of a devastating disease, they were easily overcome by human “conquerors.” a. Choose an example of a battle or other human activity such as exploration of new territory and determine the impact of microorganisms, either indigenous or transported to the region, on that activity. b. Discuss the effect that the microbe(s) had on the outcome in your example. c. Suggest whether the advent of antibiotics, food storage or preparation technology, or sterilization technology would have made a difference in the outcome. 2. Vaccinations against various childhood diseases have contributed to the entry of women, particularly mothers, into the fulltime workplace. a. Is this statement supported by data— comparing availability and extent of vaccination with employment statistics in different places or at different times? b. Before vaccinations for measles, mumps, and chickenpox, what was the incubation time and duration of these childhood diseases? What impact would such diseases have on mothers with several elementary schoolchildren at home if they had fulltime jobs and lacked substantial child care support? c. What would be the consequence if an entire generation of children (or a group of children in one country) were not vaccinated against any diseases? What do you predict would happen if these children went to college and lived in a dormitory in close proximity with others who had received all of the recommended childhood vaccines?

Prescott−Harley−Klein: Microbiology, Fifth Edition I. Introduction to Microbiology 1. The History and Scope of Microbiology © The McGraw−Hill Companies, 2002 16 Chapter 1The History and Scope of Microbiology Additional Reading General American Society for Microbiology. 1999. Celebrating a century of leadership in microbiology. ASM News 65(5). Baker, J. J. W., and Allen, G. E. 1968. Hypothesis, prediction, and implication in biology. Reading, Mass.: Addison-Wesley. Beck, R. W. 2000. A chronology of microbiology in historical context. Washington, D.C.: ASM Press. Brock, T. D. 1961. Milestones in microbiology. Englewood Cliffs, N.J.: Prentice-Hall. Bulloch, W. 1979. The history of bacteriology. New York: Dover. Chung, K.-T.; Stevens, Jr., S. E.; and Ferris, D. H. 1995. A chronology of events and pioneers of microbiology. SIM News 45(1):3–13. Clark, P. F. 1961. Pioneer microbiologists of America. Madison: University of Wisconsin Press. Collard, P. 1976. The development of microbiology. New York: Cambridge University Press. de Kruif, P. 1937. Microbe hunters. New York: Harcourt, Brace. Gabriel, M. L., and Fogel, S., editors. 1955. Great experiments in biology. Englewood Cliffs, N.J.: Prentice-Hall. Geison, G. L. 1995. The private science of Louis Pasteur. Princeton, N.J.: Princeton University Press. Hellemans, A., and Bunch, B. 1988. The timetables of science. New York: Simon and Schuster. Hill, L. 1985. Biology, philosophy, and scientific method. J. Biol. Educ. 19(3):227–31. Lechevalier, H. A., and Solotorovsky, M. 1965. Three centuries of microbiology. New York: McGraw-Hill. McNeill, W. H. 1976. Plagues and peoples. Garden City, N.Y.: Anchor Press/Doubleday. Ruestow, E. G. 1996. The microscope in the Dutch republic: The shaping of discovery. New York: Cambridge University Press. Singer, C. 1959. A history of biology, 3d ed. New York: Abelard-Schuman. Singleton, P., and Sainsbury, D. 1995. Dictionary of microbiology and molecular biology, 3d ed. New York: John Wiley and Sons. Staley, J. T.; Castenholz, R. W.; Colwell, R. R.; Holt, J. G.; Kane, M. D.; Pace, N. R.; Salyers, A. A.; and Tiedje, J. M. 1997. The microbial world: Foundation of the biosphere. Washington, D.C.: American Academy of Microbiology. Stanier, R. Y. 1978. What is microbiology? In Essays in microbiology, J. R. Norris and M. H. Richmond, editors, 1/1–1/32. New York: John Wiley and Sons. Summers, W. C. 2000. History of microbiology. In Encyclopedia of microbiology, vol. 2, J. Lederberg, editor, 677–97. San Diego: Academic Press. 1.1 The Discovery of Microorganisms Dobell, C. 1960. Antony van Leeuwenhoek and his “little animals.” New York: Dover. Ford, B. J. 1981. The Van Leeuwenhoek specimens. Notes and Records of the Royal Society of London 36(1):37–59. Ford, B. J. 1998. The earliest views. Sci. Am. 278(4):50–53. 1.2 The Conflict over Spontaneous Generation Drews, G. 1999. Ferdinand Cohn, a founder of modern microbiology. ASM News 65(8):547–53. Dubos, R. J. 1950. Louis Pasteur: Free lance of science. Boston: Little, Brown. Strick, J. E. 1997. New details add to our understanding of spontaneous generation controversies. ASM News 63(4):193–98. Vallery-Radot, R. 1923. The life of Pasteur. New York: Doubleday. 1.3 The Role of Microorganisms in Disease Brock, T. D. 1988. Robert Koch: A life in medicine and bacteriology. Madison, Wis.: Science Tech Publishers. Fredricks, D. N., and Relman, D. A. 1996. Sequence-based identification of microbial pathogens: A reconsideration of Koch’s postulates. Clin. Microbiol. Rev. 9(1):18–33. Hesse, W. 1992. Walther and Angelina Hesse— early contributors to bacteriology. ASM News 58(8):425–28. Hitchens, A. P., and Leikind, M. C. 1939. The introduction of agar-agar into bacteriology. J. Bacteriol. 37(5):485–93. Silverstein, A. M. 1989. A history of immunology. San Diego: Academic Press. 1.4 Industrial Microbiology and Microbial Ecology Chung, K.-T., and Ferris, D. H. 1996. Martinus Willem Beijerinck (1851–1931): Pioneer of general microbiology. ASM News 62(10):539–43. 1.7 The Future of Microbiology Dixon, B. 1997. Microbiology present and future. ASM News 63(3):124–25. Young, P. 1997. American academy of microbiology outlines basic research priorities. ASM News 63(10):546–50