Microbiology Lecture Slides PDF

CHAPTER 1 Lecture Slides Microbial Life: Origin and Discovery Copyright © 2024 by W. W. Norton & Company, Inc.  CHAPTER OVERVIEW 1.1 FROM GERM TO GENOME: WHAT IS A MICROBE? 1.2 MICROBES SHAPE HUMAN HISTORY 1.3 MEDICAL MICROBIOLOGY 1.4 ENVIRONMENT AND ECOLOGY 1.5 THE MICROB...

CHAPTER 1 Lecture Slides Microbial Life: Origin and Discovery Copyright © 2024 by W. W. Norton & Company, Inc.  CHAPTER OVERVIEW 1.1 FROM GERM TO GENOME: WHAT IS A MICROBE? 1.2 MICROBES SHAPE HUMAN HISTORY 1.3 MEDICAL MICROBIOLOGY 1.4 ENVIRONMENT AND ECOLOGY 1.5 THE MICROBIAL FAMILY TREE 1.6 CELL BIOLOGY AND THE DNA REVOLUTION  1.1 FROM GERM TO GENOME: WHAT IS A MICROBE?  A microbe is a living organism that requires a microscope to be seen.  Most microbes consist of a single cell, but some are multicellular. However, this does not mean that they can function as individual entities. Microbes range in size from 0.2 micrometers (mm) to just a few millimeters (mm). Viruses may be ten times smaller than the smallest cells.  Each microbe contains in its genome the capacity to reproduce its own kind. A Microbe Is a Microscopic Organism A Microbe Is a Microscopic Organism A Microbe Is a Microscopic Organism A Microbe Is a Microscopic Organism TABLE 1.1 Sizes of Some Microbes Microbe Description Approximate size Varicella-zoster Virus that causes chickenpox and shingles 100 nanometers (nm) = 10-7 meter (m) virus I Prochlorococcus Photosynthetic marine bacterium 500 nm = 5 x 10 -7 m Escherichia coli Bacterium growing within human intestine 2 micrometers (um) = 2 x 10 -6 m Spirogyra Aquatic alga that forms long filaments of cells 5 millimeters (mm) = 5 x 10 -3 m Ameba (a protist) that consumes bacteria in Pelomyxa 5 millimeters (mm) = 5 x 10 -3 m soil or water  A microbe is a Microscopic Organism  Microbes include many different types of organisms. Prokaryotes (cells lacking a nucleus): bacteria, archaea Some eukaryotes (cells with a nucleus): algae, fungi, protists Viruses and prions (acellular entities)  The bacteria, archaea, and eukaryotes—known as the three “domains”— “evolved” from a common ancestral cell. A Microbe Is a Microscopic Organism  Microbial Genomes Are Sequenced  A genome comprises the total genetic information of an organism.  The first method of DNA sequencing that was fast enough to sequence large genomes was developed by Fred Sanger. He shared the 1980 Nobel Prize in chemistry.  In 1995, scientists completed the first genome sequence of a cellular microbe, the bacterium Haemophilus influenzae.  Today’s sequencing efforts generate metagenomes, collections of sequences from diverse populations of microbes taken directly from the environment. Microbial Genomes Are Sequenced 1.2 MICROBES SHAPE HUMAN HISTORY  Microbes have shaped human cultures since our earliest civilizations. Yeasts and bacteria yielded fermented foods and beverages and spoiled meat and wine. “Rock-eating” bacteria (lithotrophs) aided metal mining and deteriorated ancient stone monuments. Microbes of all types caused diseases and famines. Microbial Disease Devastates Human Populations  Microbial Disease Devastates Human Populations  Microbial diseases have profoundly affected human demographics and cultural practices. Fourteenth century: bubonic plague caused by Yersinia pestis Nineteenth century: tuberculosis caused by Mycobacterium tuberculosis Today: acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) Microbial Disease Devastates Human Populations  Microbial Disease Devastates Human Populations  More soldiers have died of microbial infections than of wounds in battle.  The significance of disease in warfare was first recognized by the British nurse Florence Nightingale (1820–1910). She founded the science of medical statistics and professional nursing. To show the deaths of soldiers due to various causes, she devised the “polar area chart.” Medical Statistics and Health Disparities Medical Statistics and Health Disparities Microscopes Reveal the Microbial World  Robert Hooke (1635–1703) Built the first compound microscope Used it to observe mold Published Micrographia, the first manuscript that illustrated objects observed with a microscope Coined the term “cell” Microscopes Reveal the Microbial World