The Main Themes of Microbiology Chapter 01 The Main Themes of Microbiology Lecture Outline See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.

Chapter 1 Objectives List the various types of microorganisms. Identify multiple professions using microbiology. Describe the role and impact of microbes on the earth. Summarize the relative burden of human disease caused by microbes, emphasizing the differences between developed countries and developing countries. Differentiate among bacteria, archaea, and eukaryotic microorganisms. Make a time line of the development of microbiology from the 1600’s to today. List some recent microbiological discoveries of great impact. Explain what is important about the scientific method. Differentiate between the terms nomenclature, taxonomy, and classification. Create a mnemonic device for remembering taxonomic categories. Correctly write the binomial name for a microorganism. Draw a diagram of the three major domains. Describe the importance of the biogeochemical cycles and the role microbes play in maintaining the biogeochemical cylces.

Section 1.1: The Scope of Microbiology Microbiology: the specialized area of biology that deals with organisms too small to be seen with the naked eye Major groups of microorganisms: Bacteria Algae Protozoa Helminths Fungi Viruses: non-cellular (acellular), parasitic, protein-coated genetic elements that cause harm to host cells

The Scope of Microbiology Microbes are easy and difficult to study Reproduce rapidly, large populations can be grown in the laboratory Can’t be seen directly, must be analyzed through indirect methods in addition to using microscopes Microbiologists study: Cell structure and function Growth and physiology Genetics Taxonomy and evolutionary history Interactions with living and nonliving environment

Branches of Microbiology Medical Microbiology Deals with microbes that cause diseases in humans and animals Public Health Microbiology and Epidemiology Monitor and control the spread of diseases in communities USPHS, CDC, WHO

Branches of Microbiology Immunology Complex web of protective substances and cells produced in response to infection Includes vaccination, blood testing, and allergy Role of the immune system in cancer and autoimmune diseases Industrial Microbiology Safeguards our food and water Biotechnology Microbes used to create amino acids, beer, drugs, enzymes, and vitamins

Branches of Microbiology Agricultural Microbiology Relationships between microbes and domesticated plants and animals Plant specialists, animal specialists Environmental Microbiology Study the effect of microbes on the earth’s diverse habitats Aquatic, soil, and geomicrobiology, and astrobiology

Section 1.2: The Impact of Microbes on Earth Evolutionary Time Line Microbes have shaped the development of the earth’s habitats and the evolution of other life forms for billions of years Single-celled organisms arose 3.5 billion years ago and were the only living inhabitants until ~2.9 billion years ago Bacteria, archaea, and eukaryotes arose from the last universal common ancestor (LUCA)

The Impact of Microbes on Earth Eukary: true-nucleus Cells with a nucleus are classified as eukaryotes Prokary: pre-nucleus Bacteria and archaea do not have a nucleus and have been traditionally classified as prokaryotes This classification is no longer used because bacteria and archaea are so distant genetically

The Impact of Microbes on Earth Bacteria are ubiquitous. They are found: deep in the earth’s crust polar ice caps oceans inside the bodies of plants and animals

Microbial Involvement in Shaping Our Planet Microbes are deeply involved in the flow of energy and food through the earth’s ecosystems Bacteria: anoxygenic photosynthesis The production of oxygen by microbes allowed species diversification Photosynthetic microorganisms (bacteria and algae) account for more than 70% of the earth’s photosynthesis, contributing the majority of the oxygen to the atmosphere Examples of Microbial Habitats: Pond with Algae

Microbial Involvement in Shaping Our Planet Decomposition: Breakdown of dead matter and wastes Accomplished by bacteria and fungi Microbes are the main forces that drive the structure and content of soil, water, and atmosphere Gas production by microbes Microbes living within the earth’s crust Bacteria and fungi living in complex associations with plants and animals (b) © Michel & Christine Denis-Huot/Science Source

Special Topic: The Natural Recycling of Bioelements (Chapter 24) Biogeochemical cycles: All elements ultimately originate from a nonliving, long-term reservoir in the atmosphere, lithosphere, or the hydrosphere Elements cycle between the abiotic environment and the biotic environment Recycling maintains a necessary balance of nutrients in the biosphere so that they do not build up or become unavailable

Special Topic: The Natural Recycling of Bioelements (Chapter 24) Biogeochemical cycles (cont’d): Cycles are complex systems that rely on the interplay of primary producers, consumers, and decomposers All organisms participate in the recycling, but only certain categories of microorganisms have the metabolic pathways for converting inorganic compounds from one nutritional form to another

Special Topic: The Natural Recycling of Bioelements (Chapter 24) Biogeochemical cycles (cont’d): Atmospheric Cycles: Carbon Cycle Nitrogen Cycle Sedimentary Cycles: Sulfur Cycle Phosphorous Cycle

The Carbon Cycle (Chapter 24)

The Nitrogen Cycle (Chapter 24) Symbiotic relationship between rhizobia and legumes: Rhizobia: bacteria Infect legume roots and produce root nodules Enzyme system of rhizobia supplies a constant source of reduced nitrogen to the plant Nitrification: Nitrosomonas, Nitrospira, and Nitrosococcus oxidize NH3 to NO2- Nitrobacter, Nitrosospira, and Nitrosococcus perform the final oxidation of NO2- to NO3- Denitrification: Conversion of nitrate to atmospheric nitrogen Bacteria: Bacillus, Pseudomonas, Spirillum, Thiobacillus NO3-  NO2-  NO  N2O  N2 (gas) Denitrification Ammonification: decomposition of organic matter by Clostridium and Proteus produces NH4+

Sulfur Cycle (Chapter 24) Sedimentary Deposits: Rocks, Oceans, Lakes, Swamps Sources Certain Bacteria: Convert one form of sulfur to another Thiobacilli use sulfur, sulfate, thiosulfate and release acid in the process. The acid produced by Thiobacilli living on rocks help release the phosphorous from the rocks to help start the phosphorous cycle. Sulfur, Hydrogen Sulfide, Sulfate, Thiosulfate Animals: Only use an organic source of sulfur (amino acid cysteine or methionine). Plants and certain bacteria: Use only the sulfate

The Phosphorous Cycle Thiobacilli-Releases sulfuric acid on rocks releasing the inorganic phosphate

Other Cycles (Chapter 24) Involvement of microbes in cycling elements and compounds is escalated by the introduction of toxic substances in the environment. Some are converted into less harmful substances by microbial actions Bioaccumulation: Some persist and flow along with nutrients into all levels of the biosphere

Section 1.3: Human Use of Microorganisms (also part of Chapter 25) Humans have been using microorganisms for thousands of years to improve life and even shape civilizations Yeast for production of bread, wine, and beer Other fungi used for cheese production Moldy bread used in Egypt to treat wounds

Human Use of Microorganisms (also part of Chapter 25) Biotechnology: Manipulation of microorganisms to make products in an industrial setting Genetic Engineering: Manipulates the genetics of microbes, plants, and animals for the purpose of creating new products and genetically modified organisms (GMOs) (a) NREL/US Department of Energy/Dennis Schroeder (b) © Bloomberg via Getty Images

Human Use of Microorganisms (also part of Chapter 25) Recombinant DNA technology: Techniques that allow the transfer of genetic material from one organism to another and deliberately alter DNA Bioremediation: Introduction of microbes into the environment to restore stability or to clean up toxic pollutants (c) © Accent Alaska.com/Alamy

Section 1.4: Infectious Diseases and the Human Condition Pathogen: any agent such as a virus, bacterium, fungus, protozoan, or helminth that causes disease Nearly 2000 different microbes can cause disease

Infectious Diseases and the Human Condition Malaria: Kills between 440,000 and 700,000 people every year Transmitted by mosquitoes Prevention of infection is through the use of bed nets, which although inexpensive, are too expensive for poor families New (emerging) diseases as well as older (reemerging) diseases are increasing Ebola, AIDS, hepatitis C, and viral encephalitis Polio, leprosy, and parasitic worm diseases have largely been eradicated

Infectious Diseases and the Human Condition Certain diseases once considered noninfectious are now found to be caused by microbes: Gastric ulcers caused by Helicobacter pylori Link between certain cancers and bacteria and viruses Cocksackie virus has been associated with diabetes and schizophrenia Multiple sclerosis, OCD, coronary artery disease, obesity linked to chronic microbial infections Certain diseases once considered noninfectious are now found to be caused by microbes: Gastric ulcers caused by Helicobacter pylori Link between certain cancers and bacteria and viruses Cocksackie virus has been associated with diabetes and schizophrenia Multiple sclerosis, OCD, coronary artery disease, obesity linked to chronic microbial infections

Infectious Diseases and the Human Condition First Golden Age of Microbiology: “obvious” diseases were characterized and cures or preventions were devised Today, we are discovering the subtler side of microorganisms and the quiet, slow, destructive diseases they cause Female infertility caused by Chlamydia infection Liver cancer (hepatitis viruses) and cervical cancer (human papillomavirus) An increasing number of patients with weakened immune systems are subject to infections by common microbes not pathologic to healthy people Drug-resistant microbes also contribute to the increase in infectious disease

Section 1.5: General Characteristics of Microorganisms Bacterial and Archaeal cells: About 10x smaller than eukaryotic cells Lack organelles: small, double-membrane-bound structures that perform specific functions The majority of microorganisms are single-celled (all bacterial and archaeal and some eukaryotes)

General Characteristics of Microorganisms Helminths (worms) are not microorganisms but are included in the study of infectious disease: They are transmitted similarly to bacterial diseases The human body responds to them in the same way as it responds to bacterial diseases Five Types of Microorganisms

Lifestyles of Microorganisms Majority of microorganisms: Live in habitats such as soil and water Are relatively harmless and often beneficial Derive food and other factors from the nonliving environment Parasites: Harbored and nourished by the host Cause damage and disease in the host

Section 1.6: The Historical Foundations of Microbiology Early Ideas About Disease Transmission Certain foods spoiled, became inedible, or caused illness Black plague and smallpox caused by some kind of transmissible matter Belief in spontaneous generation-Disproved by Louis Pasteur

Development of the Microscope Robert Hooke: First observations of microbes in the 1600s Antonie van Leeuwenhoek: Made a crude microscope to examine threads in fabrics Made drawings of what he called “animalcules” in rainwater and scraped from his teeth (a) © Biophoto Associates/Science Source; (b) CDC/Dr. Lucille K. Georg © Tetra Images/Alamy RF

The Century of Biology 1970s: Discovery of restriction enzymes 1980s: The invention of the PCR technique 2000s: The importance of small RNAs 2010s: The role of the human microbiome Science is an ever-evolving collection of new information

The Development of Medical Microbiology Early experiments showed that microbes are everywhere: Air and dust are full of them The entire surface of the earth and its waters, and all objects are inhabited by them

The Discovery of Spores and Sterilization John Tyndall: Found that microbes in the dust and air have high heat resistance Ferdinand Cohn: Discovered and described bacterial endospores Sterile: completely free of all life forms including endospores and virus particles

Development of Aseptic Techniques Robert Koch: Linked a specific microorganism with a specific disease Dr. Oliver Wendell Holmes and Dr. Ignaz Semmelweis: Showed that women became infected in the maternity ward after examinations by physicians who had been working in the autopsy rooms

Development of Aseptic Techniques Joseph Lister: First to utilize hand washing and misting operating rooms with antiseptic chemicals Techniques became the foundation for modern microbial control still in use today © Bettmann/Corbis

Discovery of Pathogens and the Germ Theory of Disease Pasteur: Invented pasteurization Showed that human diseases could arise from infection Robert Koch: Established a series of proofs that verified the germ theory of disease

Nomenclature: Assigning Specific Names Section 1.7: Naming, Classifying, and Identifying Microorganisms Nomenclature: Assigning Specific Names Nomenclature: The assignment of scientific names to the various taxonomic categories and individual organisms Understanding and appreciation of microorganisms will be improved by learning a few general rules about how they are named

Binomial System of Nomenclature A combination of the generic (genus) and species name The genus name is always capitalized and the species name begins with a lower case letter Both names should be italicized when in print or underlined when written by hand Abbreviations: The genus name can be abbreviated to save space or if the genus name has already been stated Example: Staphylococcus aureus can be abbreviated as S. aureus

Classification: Constructing Taxonomy Attempts the orderly arrangement of organisms into a hierarchy of taxa (categories) Levels of Classification From most general to most specific: Domain Kingdom Phylum or Division Class Order Family Genus Species Identification: The process of discovering and recording the traits of organisms so they can be recognized or named and placed in a taxonomic scheme

Origin and Evolution of Microorganisms Taxonomy: The science of classifying biological species Developed by Carl von Linné in the 1700s Lays down the basic rules for classification Establishes taxonomic categories Used to organize all of the forms of modern and extinct life

Origin and Evolution of Microorganisms Phylogeny: The taxonomic scheme that represents the natural relatedness between groups of living things Based on evolution

Universal Tree of Life Charles Darwin and Ernst Haeckel: Two kingdoms: Plants and Animals Based on morphological characteristics Third and fourth kingdoms named by Haeckel: Protista and Monera Robert Whittaker Added a fifth kingdom: Fungi All kingdoms encompassed the two cell types: prokaryotic and eukaryotic Whittaker system became the standard

Tree of Life: A phylogenetic System Jump to long description