《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_P11-P15

Prescott−Harley−Klein: Microbiology, Fifth Edition Front Matter Visual Preview © The McGraw−Hill Companies, 2002 Cross-Reference Notes refer the student to major topics that are difficult and may need review in order to understand the current material. They also point the student either forward or backward to a related item of unusual interest or importance. Normally a reference is to either a specific section number or a page so that students can easily locate the item. Boldfaced Terms are the important terms and are emphasized and clearly defined when they are first used. Bold terms are listed at the end of the chapter and most appear in the glossary. New Figures and Tables have been added to this edition that summarize complex information in a concise presentation. All Figure and Table References appear in bold type within the text for easy correlation between text and visual support elements. xxiv Visual Preview 208 Chapter 10 Metabolism:The Use of Energy in Biosynthesis reduction, and regeneration. An overview of the cycle is given in figure 10.4 and the details are presented in appendix II. The Carboxylation Phase Carbon dioxide fixation is accomplished by the enzyme ribulose 1,5-bisphosphate carboxylase or ribulosebisphosphate carboxylase/ oxygenase (rubisco) (figure 10.3), which catalyzes the addition of CO2 to ribulose 1,5-bisphosphate (RuBP), forming two molecules of 3-phosphoglycerate (PGA). The Reduction Phase After PGA is formed by carboxylation, it is reduced to glyceraldehyde 3-phosphate. The reduction, carried out by two enzymes, is essentially a reversal of a portion of the glycolytic pathway, although the glyceraldehyde 3-phosphate dehydrogenase differs from the glycolytic enzyme in using NADP rather than NAD (figure 10.4). The Regeneration Phase The third phase of the Calvin cycle regenerates RuBP and produces carbohydrates such as glyceraldehyde 3-phosphate, fructose, and glucose (figure 10.4). This portion of the cycle is similar to the pentose phosphate pathway and involves the transketolase and transaldolase reactions. The cycle is completed when phosphoribulokinase reforms RuBP. To synthesize fructose 6-phosphate or glucose 6-phosphate from CO2, the cycle must operate six times to yield the desired hexose and reform the six RuBP molecules. 6RuBP 6CO2 12PGA 6RuBP fructose 6-P The incorporation of one CO2 into organic material requires three ATPs and two NADPHs. The formation of glucose from CO2 may be summarized by the following equation. 6CO2 18ATP 12NADPH 12H+ 12H2O glucose 18ADP 18Pi 12NADP+ ———— ———— ———— ATP and NADPH are provided by photosynthetic light reactions or by oxidation of inorganic molecules in chemoautotrophs. Sugars formed in the Calvin cycle can then be used to synthesize other essential molecules. CH2O C C C CH2O O OH OH H H CO2 Ribulose 1,5- bisphosphate (RuBP) P CH2O C C C CH2O P OH O H OH H2O P OOC CH2 O C COOH C CH2 O P OH H OH P H 3-phosphoglycerate (PGA) COOH P Figure 10.3 The Ribulose-1,5-Bisphosphate Carboxylase Reaction. This enzyme catalyzes the addition of carbon dioxide to ribulose 1,5-bisphosphate, forming an unstable intermediate, which then breaks down to two molecules of 3-phosphoglycerate. Ribulose 1,5- bisphosphate Ribulose- 1,5-bisphosphate carboxylase 3-phosphoglycerate 1,3-bisphosphoglycerate CO2 CH2O C HCOH O CARBOXYLATION PHASE Phosphoglycerate kinase Glyceraldehyde- 3-phosphate dehydrogenase Glyceraldehyde 3-phosphate Fructose 1,6-bisphosphate Fructose 6-phosphate Erythrose 4-phosphate Ribose 5-phosphate and other intermediates REDUCTION PHASE REGENERATION PHASE Ribulose 5- phosphate P CH2O P ADP H2O CH2OH CH2O HCOH NADPH + H+ O C O P CH2O P NADP+ Pi HCOH H O C CH2O P P HCOH C O CH2O COOH HOCH + P COOH HCOH CH2O P Biosynthetic products DHAP (1) (5) ATP ADP ATP Figure 10.4 The Calvin Cycle. This is an overview of the cycle with only the carboxylation and reduction phases in detail. Three ribulose 1,5-bisphosphates are carboxylated to give six 3-phosphoglycerates in the carboxylation phase. These are converted to six glyceraldehyde 3-phosphates, which can be converted to dihydroxyacetone phosphate (DHAP). Five of the six trioses (glyceraldehyde phosphate and dihydroxyacetone phosphate) are used to reform three ribulose 1,5-bisphosphates in the regeneration phase. The remaining triose is used in biosynthesis. rally occurring organic molecule that cannot be used by some microorganism. Actinomycetes will degrade amyl alcohol, paraffin, and even rubber. Some bacteria seem able to employ almost anything as a carbon source; for example, Burkholderia cepacia can use over 100 different carbon compounds. In contrast to these bacterial omnivores, some bacteria are exceedingly fastidious and catabolize only a few carbon compounds. Cultures of methylotrophic bacteria metabolize methane, methanol, carbon monoxide, formic acid, and related one-carbon molecules. Parasitic members of the genus Leptospira use only long-chain fatty acids as their major source of carbon and energy. It appears that in natural environments complex populations of microorganisms often will metabolize even relatively indigestible human-made substances such as pesticides. Indigestible molecules sometimes are oxidized and degraded in the presence of a growthpromoting nutrient that is metabolized at the same time, a process called cometabolism. The products of this breakdown process can then be used as nutrients by other microorganisms. Degradation and microorganisms (pp. 000–000) 5.3 Nutritional Types of Microorganisms In addition to the need for carbon, hydrogen, and oxygen, all organisms require sources of energy and electrons for growth to take place. Microorganisms can be grouped into nutritional classes based on how they satisfy all these requirements (table 5.1). We have already seen that microorganisms can be classified as either heterotrophs or autotrophs with respect to their preferred source of carbon. There are only two sources of energy available to organisms: (1) light energy, and (2) the energy derived from oxidizing organic or inorganic molecules. Phototrophs use light as their energy source; chemotrophs obtain energy from the oxidation of chemical compounds (either organic or inorganic). Microorganisms also have only two sources for electrons. Lithotrophs (i.e., “rock-eaters”) use reduced inorganic substances as their electron source, whereas organotrophs extract electrons from organic compounds. Photosynthesis light reactions (pp. 195–201); Oxidation of organic and inorganic molecules (pp. 176–95) Despite the great metabolic diversity seen in microorganisms, most may be placed in one of four nutritional classes based on their primary sources of carbon, energy, and electrons (table 5.2). The large majority of microorganisms thus far studied are either photolithotrophic autotrophs or chemoorganotrophic heterotrophs. Photolithotrophic autotrophs (often called photoautotrophs or photolithoautotrophs) use light energy and have CO2 as their carbon source. Eucaryotic algae and cyanobacteria employ water as the electron donor and release oxygen. Purple and green sulfur 5.3 Nutritional Types of Microorganisms 97 Table 5.1 Sources of Carbon, Energy, and Electrons Carbon Sources Autotrophs CO2 sole or principal biosynthetic carbon source ( pp. 207–8) a Heterotrophs Reduced, preformed, organic molecules from other organisms (chapters 9 and 10) Energy Sources Phototrophs Light ( pp. 195–201) Chemotrophs Oxidation of organic or inorganic compounds (chapter 9) Electron Sources Lithotrophs Reduced inorganic molecules ( pp. 193–94) Organotrophs Organic molecules (chapter 9) a For each category, the location of material describing the participating metabolic pathways is given within the parentheses. Table 5.2 Major Nutritional Types of Microorganisms Major Nutritional Typesa Sources of Energy, Hydrogen/Electrons, and Carbon Representative Microorganisms Photolithotrophic autotrophy Light energy Algae (Photolithoautotrophy) Inorganic hydrogen/electron (H/e– ) donor Purple and green sulfur bacteria CO2 carbon source Cyanobacteria Photoorganotrophic heterotrophy Light energy Purple nonsulfur bacteria (Photoorganoheterotrophy) Organic H/e– donor Green nonsulfur bacteria Organic carbon source (CO2 may also be used) Chemolithotrophic autotrophy Chemical energy source (inorganic) Sulfur-oxidizing bacteria (Chemolithoautotrophy) Inorganic H/e– donor Hydrogen bacteria CO2 carbon source Nitrifying bacteria Iron-oxidizing bacteria Chemoorganotrophic heterotrophy Chemical energy source (organic) Protozoa (Chemoorganoheterotrophy) Organic H/e– donor Fungi Organic carbon source Most nonphotosynthetic bacteria (including most pathogens) a Bacteria in other nutritional categories have been found. The categories are defined in terms of energy, electron, and carbon sources. Condensed versions of these names are given in parentheses.

Prescott−Harley−Klein: Microbiology, Fifth Edition Front Matter To The Student © The McGraw−Hill Companies, 2002 xxv TO THE STUDENT One of the most important factors contributing to success in college, and in microbiology courses, is the use of good study techniques. This textbook is organized to help you to study more efficiently. But even a text with many learning aids is not effective unless used properly. Thus this section briefly outlines some practical study skills that will help ensure success in microbiology and make your use of this textbook more productive. Many of you already have the study skills mentioned here and will not need to spend time reviewing familiar material. These suggestions are made in the hope that they may be useful to those who are unaware of approaches like the SQ4R technique for studying textbooks. Time Management and Study Environment Many students find it difficult to study effectively because of a lack of time management and a proper place to study. Often a student will do poorly in courses because not enough time has been spent studying outside class. For best results you should plan to spend at least an average of four to eight hours a week outside class working on each course. There is sufficient time in the week for this, but it does require time management. If you spend a few minutes early in the morning planning how the day is to be used and allow adequate time for studying, much more will be accomplished. Students who make efficient use of every moment find that they have plenty of time for recreation. A second important factor is a proper place to study so that you can concentrate and efficiently use your study time. Try to find a quiet location with a desk and adequate lighting. If possible, always study in the same place and use it only for studying. In this way you will be mentally prepared to study when you are at your desk. This location may be in the dorm, the library, a special study room, or somewhere else. Wherever it is, your study area should be free from distractions—including friends who drop by to socialize. Much more will be accomplished if you really study during your designated study times. Making the Most of Lectures Attendance at lectures is essential for success. Students who chronically miss classes usually do not do well. To gain the most from lectures, it is best to read any relevant text material beforehand. Be prepared to concentrate during lectures; do not simply sit back passively and listen to the instructor. During the lecture record your notes in a legible way so that you can understand them later. It is most efficient to employ an outline or simple paragraph format. The use of abbreviations or some type of shorthand notation often is effective. During lecture concentrate on what is being said and be sure to capture all of the main ideas, concepts, and definitions of important terms. Do not take sketchy notes assuming that you will remember things because they are easy or obvious; you won’t. Diagrams, lists, and terms written on the board are almost always important, as is anything the instructor clearly emphasizes by tone of voice. Feel free to ask questions during class when you don’t understand something or wish the instructor to pursue a point further. Remember that if you don’t understand, it is very likely that others in the class don’t either but simply aren’t willing to show their confusion. As soon as possible after a lecture, carefully review your notes to be certain that they are complete and understandable. Refer to the textbook when uncertain about something in your notes; it will be invaluable in clearing up questions and amplifying major points. When studying your notes for tests, it is a good idea to emphasize the most important points with a highlighter just as you would when reading the textbook. Studying the Textbook Your textbook is one of the most important learning tools in any course and should be very carefully and conscientiously used. Many years ago Francis P. Robinson developed a very effective study technique called SQ3R (survey, question, read, recite, and review). More recently L. L. Thistlethwaite and N. K. Snouffer have slightly modified it to yield the SQ4R approach (survey, question, read, revise, record, and review). This latter approach is summarized here: 1. Survey. Briefly scan the chapter to become familiar with its general content. Quickly read the title, introduction, summary, and main headings. Record the major ideas and points that you think the chapter will make. If there are a list of chapter concepts and a chapter outline, pay close attention to these. This survey should give you a feel for the topic and how the chapter is approaching it. 2. Question. As you reach each main heading or subheading, try to compose an important question or two that you believe the section will answer. This preview question will help focus your reading of the section. It is also a good idea to keep asking yourself questions as you read. This habit facilitates active reading and learning. 3. Read. Carefully read the section. Read to understand concepts and major points, and try to find the answer to your preview question(s). You may want to highlight very important terms or explanations of concepts, but do not indiscriminantly highlight everything. Be sure to pay close attention to any terms printed in color or boldface since the author(s) considered these to be important. 4. Revise. After reading the section, revise your question(s) to more accurately reflect the section’s contents. These questions should be concept type questions that force you to bring together a number of details. They can be written in the margins of your text

Prescott−Harley−Klein: Microbiology, Fifth Edition I. Introduction to Microbiology 1. The History and Scope of Microbiology © The McGraw−Hill Companies, 2002 PART I Introduction to Microbiology Chapter 1 The History and Scope of Microbiology Chapter 2 The Study of Microbial Structure: Microscopy and Specimen Preparation Chapter 3 Procaryotic Cell Structure and Function Chapter 4 Eucaryotic Cell Structure and Function CHAPTER 1 The History and Scope of Microbiology Louis Pasteur, one of the greatest scientists of the nineteenth century, maintained that “Science knows no country, because knowledge belongs to humanity, and is a torch which illuminates the world.” Outline 1.1 The Discovery of Microorganisms 2 1.2 The Conflict over Spontaneous Generation 2 1.3 The Role of Microorganisms in Disease 7 Recognition of the Relationship between Microorganisms and Disease 7 The Development of Techniques for Studying Microbial Pathogens 8 Immunological Studies 9 1.4 Industrial Microbiology and Microbial Ecology 10 1.5 Members of the Microbial World 11 1.6 The Scope and Relevance of Microbiology 11 1.7 The Future of Microbiology 13 Concepts 1. Microbiology is the study of organisms that are usually too small to be seen by the unaided eye; it employs techniques—such as sterilization and the use of culture media—that are required to isolate and grow these microorganisms. 2. Microorganisms are not spontaneously generated from inanimate matter but arise from other microorganisms. 3. Many diseases result from viral, bacterial, fungal, or protozoan infections. Koch’s postulates may be used to establish a causal link between the suspected microorganism and a disease. 4. The development of microbiology as a scientific discipline has depended on the availability of the microscope and the ability to isolate and grow pure cultures of microorganisms. 5. Microorganisms are responsible for many of the changes observed in organic and inorganic matter (e.g., fermentation and the carbon, nitrogen, and sulfur cycles that occur in nature). 6. Microorganisms have two fundamentally different types of cells—procaryotic and eucaryotic—and are distributed among several kingdoms or domains. 7. Microbiology is a large discipline, which has a great impact on other areas of biology and general human welfare

Prescott−Harley−Klein: Microbiology, Fifth Edition I. Introduction to Microbiology 1. The History and Scope of Microbiology © The McGraw−Hill Companies, 2002 Dans les champs de l’observation, le hasard ne favorise que les esprits préparés. (In the field of observation, chance favors only prepared minds.) —Louis Pasteur One can’t overemphasize the importance of microbiology. Society benefits from microorganisms in many ways. They are necessary for the production of bread, cheese, beer, antibiotics, vaccines, vitamins, enzymes, and many other important products. Indeed, modern biotechnology rests upon a microbiological foundation. Microorganisms are indispensable components of our ecosystem. They make possible the cycles of carbon, oxygen, nitrogen, and sulfur that take place in terrestrial and aquatic systems. They also are a source of nutrients at the base of all ecological food chains and webs. Of course microorganisms also have harmed humans and disrupted society over the millennia. Microbial diseases undoubtedly played a major role in historical events such as the decline of the Roman Empire and the conquest of the New World. In 1347 plague or black death (see chapter 39) struck Europe with brutal force. By 1351, only four years later, the plague had killed 1/3 of the population (about 25 million people). Over the next 80 years, the disease struck again and again, eventually wiping out 75% of the European population. Some historians believe that this disaster changed European culture and prepared the way for the Renaissance. Today the struggle by microbiologists and others against killers like AIDS and malaria continues. The biology of AIDS and its impact (pp. 878–84) In this introductory chapter the historical development of the science of microbiology is described, and its relationship to medicine and other areas of biology is considered. The nature of the microbial world is then surveyed to provide a general idea of the organisms and agents that microbiologists study. Finally, the scope, relevance, and future of modern microbiology are discussed. Microbiology often has been defined as the study of organisms and agents too small to be seen clearly by the unaided eye—that is, the study of microorganisms. Because objects less than about one millimeter in diameter cannot be seen clearly and must be examined with a microscope, microbiology is concerned primarily with organisms and agents this small and smaller. Its subjects are viruses, bacteria, many algae and fungi, and protozoa (see table 34.1). Yet other members of these groups, particularly some of the algae and fungi, are larger and quite visible. For example, bread molds and filamentous algae are studied by microbiologists, yet are visible to the naked eye. Two bacteria that are visible without a microscope, Thiomargarita and Epulopiscium, also have been discovered (see p. 45). The difficulty in setting the boundaries of microbiology led Roger Stanier to suggest that the field be defined not only in terms of the size of its subjects but also in terms 2 Chapter 1The History and Scope of Microbiology of its techniques. A microbiologist usually first isolates a specific microorganism from a population and then cultures it. Thus microbiology employs techniques—such as sterilization and the use of culture media—that are necessary for successful isolation and growth of microorganisms. The development of microbiology as a science is described in the following sections. Table 1.1 presents a summary of some of the major events in this process and their relationship to other historical landmarks. 1.1 The Discovery of Microorganisms Even before microorganisms were seen, some investigators suspected their existence and responsibility for disease. Among others, the Roman philosopher Lucretius (about 98–55 B.C.) and the physician Girolamo Fracastoro (1478–1553) suggested that disease was caused by invisible living creatures. The earliest microscopic observations appear to have been made between 1625 and 1630 on bees and weevils by the Italian Francesco Stelluti, using a microscope probably supplied by Galileo. However, the first person to observe and describe microorganisms accurately was the amateur microscopist Antony van Leeuwenhoek (1632–1723) of Delft, Holland (figure 1.1a). Leeuwenhoek earned his living as a draper and haberdasher (a dealer in men’s clothing and accessories), but spent much of his spare time constructing simple microscopes composed of double convex glass lenses held between two silver plates (figure 1.1b). His microscopes could magnify around 50 to 300 times, and he may have illuminated his liquid specimens by placing them between two pieces of glass and shining light on them at a 45° angle to the specimen plane. This would have provided a form of dark-field illumination (see chapter 2) and made bacteria clearly visible (figure 1.1c). Beginning in 1673 Leeuwenhoek sent detailed letters describing his discoveries to the Royal Society of London. It is clear from his descriptions that he saw both bacteria and protozoa. 1.2 The Conflict over Spontaneous Generation From earliest times, people had believed in spontaneous generation—that living organisms could develop from nonliving matter. Even the great Aristotle (384–322 B.C.) thought some of the simpler invertebrates could arise by spontaneous generation. This view finally was challenged by the Italian physician Francesco Redi (1626–1697), who carried out a series of experiments on decaying meat and its ability to produce maggots spontaneously. Redi placed meat in three containers. One was uncovered, a second was covered with paper, and the third was covered with a fine gauze that would exclude flies. Flies laid their eggs on the uncovered meat and maggots developed. The other two pieces of meat did not produce maggots spontaneously. However, flies were attracted to the gauze-covered container and laid their eggs on the gauze; these eggs produced maggots