Microbiology - Introduction to Microbiology PDF

Microbiology – BIO210 Chapter 1: Introduction to Microbiology SPRING 2024 Intro Learning Outcomes: By the end of this lecture, you should be able to: ❖Understand the general characteristics of Microorganisms ❖The history of microorganisms ❖Paths that led to discovery...

Microbiology – BIO210 Chapter 1: Introduction to Microbiology SPRING 2024 Intro Learning Outcomes: By the end of this lecture, you should be able to: ❖Understand the general characteristics of Microorganisms ❖The history of microorganisms ❖Paths that led to discovery of microorganisms  Microbiology The study of organisms too small to be seen without magnification The term microbiology = mikros [small] + bios [life] + logos [study]. Microorganisms include: – Bacteria – Viruses – Fungi – Protozoa – Helminths (microscopic worms) – Algae The classification of living things helps us to organize and group organisms based on their characteristics. Domain -Kingdom -Phylum - Class - Order - Family - Genus - Species THE CLASSIFICATION SYSTEM/ TAXONOMY  The Evolutionary Relationships Between Earth’s Inhabitants The domain classification is the highest level of taxonomic classification in the organism classification system. The domain can be broken down into three types: Archaea domain, Eukaryotic domain, and the (Eu)Bacteria domain. 3 Domains of Life Bacteria - true bacteria Archaea - odd bacteria that live in extreme environments, high salt, heat, etc. Eukarya - have a nucleus and organelles  Microorganisms Cellular Acellular Prokaryotic cells Eukaryotic cells Not cells No nucleus Have nucleus No cell membrane No intracellular organelles Have intracellular organelles No nucleus. Example: Bacteria Example: Yeast, Parasites, Algae Example: Viruses  Importance and Scope of Microbiology Microbiology is an applied Medicine science that has great impact on Bio- Biotechnology genetics, biochemistry, food remediation sciences, ecology, immunology, Microbiology agriculture, medicine and many other disciplines. Industry Environment Agriculture  Origins of Microorganisms Bacteria-like organisms have existed on earth for about 3.5 billion years – Prokaryotes (pre-nucleus): Simple cells – Eukaryotes (true nucleus): Complex cells Humans appeared. Mammals appeared. Cockroaches, termites appeared. Probable origin of Prokaryotes Eukaryotes Reptiles earth appeared. appeared. appeared. 15 billion 4 billion 3 billion 2 billion 1 billion Present* years ago years ago years ago years ago years ago time  Microbial Structure Prokaryote – microscopic, unicellular organisms, lack nuclei and membrane-bound organelles Eukaryote – unicellular (microscopic) and multicellular, nucleus and membrane-bound organelles Viruses - Acellular, parasitic particles composed of a nucleic acid and protein  Microbial Diversity: 6 Types of Microbes Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Reproductive spores Janice Carr/CDC © Tom Volk © Charles Krebs Photography Bacteria: Mycobacterium tuberculosis, a Fungi: Thamnidium, a filamentous Algae: desmids, Spirogyra filament, and diatoms rod-shaped cell (15,500x). fungus (400x) (golden cells) (500x). A single virus particle CDC © Yuuji Tsukii, Protist Information Server CDC * Virus: Herpes simplex, cause of cold Protozoa: A pair of Vorticella (500x), stalked cells Helminths: Cysts of the parasitic roundworm, sores (100,000x). that feed by means of a whirling row of cilia. Trichinella spiralis (250x) embedded in muscle.  opyri ht The raw ill o panies In er ission re uire or repro u tion or isplay Ran e o hu an Repro u tive stru ture ouse eye o brea ol u leus olonial al a oeba Ran e o li ht i ros ope Re bloo ell hite bloo ell Microbial ost ba teria all between in si e to Ro shape ba teria o us shape ba teria Dimensions ba teria n ba teria o virus n I virus epatitis B virus Ran e n oliovirus o ele tron la ellu i ros ope ar e protein n ia eter o Re uire ino a i spe ial s all ole ule i ros opes n y ro en ato n stro o o eters  Microbes in Energy & Nutrient Flow The flow of energy and food through the earth’s ecosystems – Photosynthesis: Light fueled conversion of carbon dioxide to organic material – Decomposition: Breakdown of dead matter and wastes into simple compounds  Human Use of Microorganisms Biotechnology: Production of foods, drugs, and vaccines using living organisms Genetic engineering: Manipulating the genes of organisms to make new products Bioremediation: Using living organisms to remedy an environmental problem *  Microbial Applications Microorganisms have major impacts on the world in which we live. Microorganisms impact our health, the foods we eat, the water we drink, and even the air we breathe. Microbes can be used to produce valuable products and the many ways in which microorganisms touch our lives. *  Lifestyles of Microorganisms Majority live a free existence, are relatively harmless and often beneficial Some microorganisms have close associations with other organisms – Parasites live on or in the body of another organism called the host and it damages the host. *  Microbes & Infectious Diseases Parasitic diseases 2.5% Miscellaneous 1.5% Pathogens: Microbes that do harm, cause disease 5% 26% 7% Nearly 2,000 different microbes cause diseases 9% 10 B new infections/year worldwide 11% 18% 17.5% 12 M deaths from infections/year worldwide *  Historical Foundations of Microbiology Thousands of microbiologists over 300 years Prominent discoveries include: – Microscopy – Scientific method – Development of medical microbiology – Microbiology techniques *  Scientific Method Approach taken by scientists to explain a certain natural phenomenon Form a hypothesis - a tentative explanation that can be supported or refuted – Deductive approach “I …, then….” A lengthy process of experimentation, analysis, and testing either supports or refutes the hypothesis Results must be published and repeated by other investigators. If hypothesis is supported by a growing body of evidence and survives rigorous scrutiny, it moves to the next level of confidence - it becomes a theory. If evidence of a theory is so compelling that the next level of confidence is reached, it becomes a Law or principle. *  Discovery of Spores and Sterilization John Tyndall and Ferdinand Cohn each demonstrated the presence of heat resistant forms of some microbes. – Cohn determined these forms to be heat-resistant bacterial endospores. Sterility requires the elimination of all life forms including endospores and viruses. * History of Microbiology Antonie van Leeuwenhoek (1632-1723) Dutch linen merchant re ar e as ather o “Bacteriology‟ an “Protozoology‟ First to observe living microbes Single-lens magnified up to 300X  Spontaneous Generation Spontaneous Generation is an early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter (flies from manure, etc.) Louis Pasteur eventually disproved spontaneous generation and proved the Theory of Biogenesis - the idea that living things can only arise from other living things  The Germ Theory of Disease Many diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc. which was the belief for centuries. (Why?) Two major contributors: Louis Pasteur and Robert Koch * History of Microbiology Louis Pasteur (1822-1895) Showed microbes caused fermentation and spoilage Regarded as “Father of Microbiology and Immunology‟. Disproved spontaneous generation of microorganisms Developed pasteurization Demonstrated what is now known as Germ Theory of Disease * History of Microbiology Robert Koch (1843-1910) a German microbiologist Established K h’ u -a sequence of experimental steps that verified the germ theory Identified cause of anthrax, TB, and cholera Developed pure culture methods/culture technique to culture the bacteria in the laboratory Awarded Nobel Prize of medicine in 1905 * History of Microbiology Alexander Fleming A Scotland doctor and biochemist born in 1881. Contributed knowledge about antibiotic Penicillin for this kind of work Awarded Nobel Prize in 1945. Worked on antimicrobial substances. That is not toxic to human body but toxic to microbial body. Discovered bacteriolytic substance lysosome in the animal tissue.  Taxonomy Taxonomy: organizing, classifying, and naming living things – Formal system originated by Carl von Linné Concerned with: – Classification – orderly arrangement of organisms into groups – Nomenclature – assigning names – Identification – determining and recording traits of organisms for placement into taxonomic schemes *  Assigning Specific Names Binomial (scientific) nomenclature Gives each microbe 2 names: – Genus - capitalized – species - lowercase Both italicized or underlined – Staphylococcus aureus (S. aureus) or Staphylococcus aureus (S. aureus) Inspiration for names is extremely varied and often imaginative! Sometimes informative. *  The Origin and Evolution of Microorganisms Phylogeny: natural relatedness between groups of organisms Evolution: living things change gradually over long period of time All new species originate from preexisting species Closely related organism have similar features because they evolved from common ancestral forms Evolution usually progresses toward greater complexity Changes favoring survival are retained & less beneficial changes are lost. *