講稿課件微生物chapter1-main themes of microbiology

1、Chapter One The main themes of microbiology 1.1 The scope of microbiology 1.2 The general characteristics of microorganisms1.3 The historical foundations of microbiology 1.4 Taxonomy: organizing, classifying, and naming (Basic Principles of Microbiology) Microbe (or Microorganism): an organism that

2、so small that, normally, it cannot be seen without the aid of a microscope, including virus, bacteria, archaea, fungi and alga, and protozoa.1.1 The scope of microbiology Microbiology is a specialized area of biology that deals with living things ordinarily too small to be seen without magnification

3、. - bacteria viruses fungi protozoaAlgaehelminths (worms)Microorganisms:AspergillusLecane lunarisStrongyloidesThe immediate environment in which a microbial populationlives is called its habitat. Populations of cells interact withother populations in microbial communitiesMicroorganisms and Their Env

4、ironmentsA bacterial community developed in a lakeChapter 1Microbes are Involved inInfectious disease Nutrient production and energy flow position （分解）Biotechnology production of foods, drugs and vaccinesGenetic engineeringBioremediation （生物修復(fù)）FermentationN2 fixationBenefits and harms of Microorgani

5、smsNatural gas (methaneChapter 1Infectious DiseasesNearly 2,000 different microbes cause diseases.10 billion new infections/year worldwide13 million deaths from infections/year worldwideBranches of MicrobiologyImmunologyPublic health microbiology and epidemiologyFood, dairy, Aquatic, Soil, Aero Micr

6、obiologyBiotechnologyGenetic engineering and binant DNA technologyThe science of microbiology revolves around two interconnected themes: (1) understanding the living world of microscopic organisms, (2) applying our understanding of microbial life processes for the benefit of humankind and planet Ear

7、th.Chapter 11.2 The general characteristics of microorganisms(1) Small size, Simple structure, various shapes; Microbe size range Nature of cellViruses 0.01-0.25m AcellularBacteria 0.1-750 m ProkaryoteFungi 2 m-1m EukaryoteProtozoa 2-1000m EukaryoteChapter 1(2). High diversityFigure 2.17 The phyloge

8、netic tree of life as defined by comparative rRNA gene sequencing.(Brock)(3) Fast evolution when selective pressure is strong (4) Widely distributed in various environment with large numbers Estimated cell number of microbes: 2.5 X 1030(Brock)Figure 1.3 The properties of cellular life (Brock)(5)They

9、 have the common properties of Cellular Life(6) Common structures of MicrobesProcaryotes and Eukaryotes procaryote microscopic, unicellular organisms, lack nucleus and membrane-bound organelles eucaryote unicellular (microscopic) and multicellular, nucleus and membrane-bound organellesViruses acellu

10、lar, parasitic particles composed of a nucleic acid and protein(7) Common cellular catalytic and genetic functions of Microbes(Brock)300 years of contributions by many prominent discoveries include: microscopy scientific method development of medical microbiology microbiology techniques1.3 The histo

11、rical foundations of microbiology1) A Dutch merchant. self-made microbiologist2) Not the first to develop a len or microscope but the first to describe living microbes3) Single-lens magnified up to 300X1. The Historical Roots of Microbiology: Hooke, van Leeuwenhoek, and CohnAnton van Leeuwenhoek (16

12、32-1723)Hookes microscopeLeeuwenhoeks microscopeDrawing example of bacteria Ferdinand Cohn (18281898)Ferdinand Cohn founded the field of bacteriology and discovered bacterial endospores.Sulfur bacterium BeggiatoaEndospore-forming bacterium Bacillus2. The Debate Over Spontaneous GenerationThe hypothe

13、sis that living organisms arise from nonliving matter is called spontaneous generation. According to spontaneous generation, a “vital force forms life.The Alternative hypothesis, that the living organisms arise from preexisting life, is called biogenesis.Francesco RediEvidence Pro and Con(1626-1678)

14、: Louis Jablot16701748: John Needham put boiled nutrient broth into covered flasks.Evidence Pro and ConConditionsResultsNutrient broth heated, then placed in sealed flaskMicrobial growthFrom where did the microbes come?Spontaneous generation or biogenesis?1861: Louis Pasteur demonstrated that microo

15、rganisms are present in the air.Evidence Pro and ConConditionsResultsNutrient broth placed in flask, heated, not sealedMicrobial growthNutrient broth placed in flask, heated, then sealedNo microbial growthSpontaneous generation or biogenesis?3. The Golden Age of Microbiology1822-1895a chemist who wa

16、s one of the first to recognize the significance of optical isomersShowed microbes caused fermentation & spoilageDisproved spontaneous generationDeveloped sterilization techniques.Developed vaccines for the diseases anthrax, fowl cholera, and rabies Louis Pasteur one of the founders of microbiology.

17、1860s: Joseph Lister used phenol to prevent surgical wound infections after looking at Pasteurs work showing microbes are in the air, can spoil food, and cause animal diseases.1876: Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, Kochs postulates, used

18、 to prove that a specific microbe causes a specific disease.The Germ Theory of DiseaseSolid Media, the Petri Plate, and Pure CulturesRobert Koch was the first to grow bacteria on solid culture media. Walter Hesse ( 1846-1911): Used Agar as a solidifying agent to harden media. Agar is extracted from

19、seaweeds red algae.Rechard Petri ( 1852-1921): Used agar dish to provide a large area to grow.Martinus Beijerinck and the Enrichment Culture TechniqueIn enrichment cultures microorganisms are isolated from natural samples using highly selective techniques of adjusting nutrient and incubation conditi

20、ons to favor a particular metabolic group of bic nitrogen-fixing bacteriumAzotobacterSergei Winogradsky, Chemolithotrophy, and Nitrogen Fixation(18561953)(18511931)He isolated several key bacteria such as the nitrifying bacteriaand the sulfur bacteriaChemolithotrophy4. Development of M

21、icrobiology in the twentieth century1990-2001 human genome project, microbial genome sequeneFrederick Griffith (1928) lays the foundation for modernmolecular genetics by his discovery oftransformation in bacteria(1944) Oswald Avery, Colin MacLeod, and Maclyn McCarty show that DNA is the genetic mate

22、rial.(1944) Joshua Lederberg and E. L. Tatum discover conjugation in bacteria.(1929) Alexander Fleming discovers and describes the properties of the first antibiotic, penicillin(1953) James Watson and Francis Crick determine the structure of DNA(1975)Frederick Sanger sequencing(1983) Kary Mullis dev

23、eloped polymerase chain reaction (PCR)(1990-2000 and current)Genomics ageMicrobial Genome Growth4. The Modern Era of MicrobiologyWe are currently in the era of “molecular microbiology.”Many advances in microbiology today are fueled by genomics, the mapping, sequencing, and analysis of genomes.Microb

24、iology in ChinaMade wine 5000 years ago Ming Dynasty. In China, powdered smallpox scabs were blown up the noses of the healthy.2 A. D.，張仲景：eating the meat of ill animal should be prohibited1910, 伍連德, controlled the spread of pneumonic plague in Harbin1957,湯飛凡, isolated Chlamydia trachomatis, the pat

25、hogen of trachoma1979,戴芳瀾, 中國(guó)真菌總匯1950,俞大紱, founded plant pothology1936-1980, 張憲武,陳華癸，nitrogen fixation study， agricultural microbiology黃禎祥,高尚蔭, founded virology1. Answer the Review question 1, 2, 3, 6, 8 (Brock page 22)2. Listen video “history of microbiology” or “the brief history of microbiology” Deadlines: Sept. 19Prepare Discussion 1 (9.17)What do you learn from the historical stories?Which story most impress you, Why do you think certain scientist is so great?Describe the remarkable microbe e