History of Micro_mcb221.ppt PDF

The Microbial World and You HISTORY Chapter 1 The Microbial World and You What is Microbiology? The branch of biology which dealing with the study of microorganisms, or microbes( a diverse group of minute, simple life forms that include bacteria, arc...

The Microbial World and You HISTORY Chapter 1 The Microbial World and You What is Microbiology? The branch of biology which dealing with the study of microorganisms, or microbes( a diverse group of minute, simple life forms that include bacteria, archaea, algae, fungi, protozoa, and viruses). The field is also concerned with the structure, function, and classification of such organisms and with ways of both exploiting and controlling their activities. Microbes, or microorganisms are very small living things that are usually can not be seen with the naked eye. Most of them are harmless (99%), but some are pathogenic (1%) microorganisms which can affect human, animals, plants and other microorganisms. “Germ” refers to a rapidly growing cell. Chapter 1 The Microbial World and You Advantages of microbes ? Microbes have many important and beneficia Biological functions - Decompose organic waste. (recycle nutrient) - Producer in the ecosystem (algae, and some bacteria) capture the energy from sun light and convert it to food, forming the basis of food chain (photosynthesis) - -Food industry: Produce fermented foods such as vinegar, cheese, yogurt and bread. - Other industries: Produce industrial chemicals such as ethyl alcohol and acetone. -Nitrogen fixation: some bacteria can take the nitrogen from air and incorporate it into soil. - Medicine and medical research: many antibiotic and other drugs are naturally synthesized by microbes )penicillin made by molds). -Digestion: -Humans and animals are have microorganisms in their digestive tract that are essential for digestion, and overall health * Therefore, microbes are essential for life in the earth. Chapter 1 The Microbial World and You The importance of study the microbiology The study of microbiology provide us with: - To understand how they affect our lives and how we can exploit them. - Knowledge of Microbes allows humans to prevent microbial disease and food spoilage. - Led to aseptic techniques to prevent contamination in medicine, food industry and in the microbiology laboratories Chapter 1 The Microbial World and You Example of microorganisms Chapter 1 The Microbial World and You History of Microbiology Ancestors of bacteria were the first life on Earth. History of Microbiology The early Greeks believed that living things could originate from nonliving matter (abiogenesis) (the goddess Gea could create life from stones). Aristotle discarded this notion, but he still held that animals could arise spontaneously from dissimilar organisms or from soil. ( spontaneous generation) This concept was still felt as late as the 17th century, but toward the end of that century a several observations, experiments, and History of Microbiology In 1665, Robert Hooke (Englishman) reported that living things were composed of little boxes or cells using a microscope (was the first to use a microscope to observe living things). (Dutch) Antonie van Leeuwenhoek (1632–1723) Microbiology essentially began with the development of the microscope. Although others may have seen microbes before him, Antonie van Leeuwenhoek (1632–1723) was one of the first people to observe microorganisms (1675) , using a microscope of his own design. Chapter 1 The Microbial World and You History of Microbiology -Description of protozoa, basic types of bacteria, yeasts, and algae. - observed and described live microorganisms in teeth scrapings, rain water, peppercorn infusions and faces as Animalcules. Chapter 1 The Microbial World and You History of Microbiology So now there are two hypotheses: The hypothesis 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. Chapter 1 The Microbial World and You History of Microbiology Francesco Redi (1626-1697) (Italian) Performed an experiment to disprove spontaneous generation. He showed that the maggots would not arise from decaying meat, when it is covered. - He set up an experiment to disprove spontaneous generati of maggots. Filled 2 jars with decaying meat, sealed one and left the other open (only the open jar developed maggots). Chapter 1 The Microbial World and You History of Microbiology Another experiment was set up in which a jar was covered with a fine mesh instead of being sealed so that fresh air could enter the jar again, only the open jar developed maggots) Proved that the flies had to come in contact with the meat and lay their eggs on it, maggots did not arise spontaneously. Can you think of an experiment that could disprove spontaneous generation? Chapter 1 The Microbial World and You History of Microbiology Redi filled six jars with decaying meat. Conditions Results 3 jars covered with No maggots fine net 3 open jars Maggots appeared From where did the maggots come? What was the purpose of the sealed jars? Spontaneous generation or biogenesis? Chapter 1 The Microbial World and You History of Microbiology 1861: Louis Pasteur (Father of medical bacteriology) demonstrated that microorganisms are present in the air. Conditions Results Nutrient broth placed Microbial growth in flask, heated, not sealed Nutrient broth placed No microbial growth in flask, heated, then sealed Spontaneous generation or biogenesis? Chapter 1 The Microbial World and You History of Microbiology Next experiment, Pasteur’s S-shaped flask kept microbes out but let air in. These experiments form the basis of aseptic technique Chapter 1 The Microbial World and You History of Microbiology The Golden Age of Microbiology 1857-1914 Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs Chapter 1 The Microbial World and You History of Microbiology Pasteur showed that microbes are responsible for fermentation. Fermentation is the conversion of sugar to alcohol to make beer and wine. Microbial growth is also responsible for spoilage of food. Bacteria that use alcohol and produce acetic acid spoil wine by turning it to vinegar (acetic acid). Chapter 1 The Microbial World and You History of Microbiology Pasteur demonstrated that these spoilage bacteria could be killed by heat (62.8 c) that was not hot enough to evaporate the alcohol in wine. This application of a high heat for a short time (30 mins) is called pasteurization.  Contribution of Louis Pasteur He coined the term “ Microbiology” He disproved the Spontaneous generation Theory He demonstrated that anthrax was caused by bacteria. He invented the process of pasteurization and fermentation.. The development of effective vaccine (rabies and anthrax) Pasteur works along with subsequent observations by Lister, Koch and others established the germ theory of disease Chapter 1 The Microbial World and You History of Microbiology The Germ Theory of Disease 1835: Agostino Bassi showed a silkworm disease was caused by a fungus. 1865: Pasteur believed that another silkworm disease was caused by a protozoan. 1840s: Ignaz Semmelwise Advocated washing hands to stop the spread of disease. Chapter 1 The Microbial World and You History of Microbiology The Germ Theory of Disease 1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteur’s work showing microbes are in the air, can spoil food, and cause animal diseases. Chapter 1 The Microbial World and You History of Microbiology The Germ Theory of Disease 1876: Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, Koch’s postulates, used to prove that a specific microbe causes a specific disease. Koch was a physician and Pasteur’s young rival Chapter 1 The Microbial World and You History of Microbiology Koch's Postulates are used to prove the cause of an infectious disease. Chapter 1 The Microbial World and You History of Microbiology Koch's Postulates are a sequence of experimental steps to relate a specific microbe to a specific disease. 1892 Dmitri Iosifovich Ivanovski : Discovered viruses Chapter 1 The Microbial World and You History of Microbiology A young milkmaid informed the physician Edward Jenner that she could not get smallpox because she had already been sick from cowpox. 1796: Edward Jenner inoculated a person with cowpox virus. The person was then protected from smallpox. Called vaccination from vacca for cow The protection is called immunity Chapter 1 The Microbial World and You History of Microbiology What can you say about the cowpox and smallpox viruses? Chapter 1 The Microbial World and You History of Microbiology Vaccinations produced from avirulent microbial strains produced from live viruses produced from viral particles Chapter 1 The Microbial World and You History of Microbiology Chemotherapy – treatment with chemicals Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics. Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes. Quinine from tree bark was long used to treat malaria. Chapter 1 The Microbial World and You History of Microbiology Chemotherapy – treatment with chemicals 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis. 1930s: Sulfonamides were synthesized. Chapter 1 The Microbial World and You History of Microbiology 1928: Alexander Fleming discovered the first antibiotic. He observed that Penicillium fungus made an antibiotic, penicillin, that killed Staphylococcus aureus. 1940s: Penicillin was tested clinically and mass produced. Chapter 1 The Microbial World and You Modern Developments Bacteriology is the study of bacteria. Mycology is the study of fungi. Parasitology is the study of protozoa and parasitic worms. Recent advances in genomics, the study of an organism’s genes, have provided new tools for classifying microorganisms. Chapter 1 The Microbial World and You Classification of Microbes Taxonomy The science of classifying organisms Provides universal names for organisms Provides a reference for identifying organisms Chapter 1 The Microbial World and You Classification of Microbes Taxonomy Systematics or phylogeny The study of the evolutionary history of organisms All Species Inventory (2001-2025) To identify all species of life on Earth Chapter 1 The Microbial World and You Classification of Microbes Taxonomic Hierarchy Domain Binomal Nomenclature uses Kingdom the Genus and Phylum Species name to Class identify each creature. Order Family Genus Species Chapter 1 The Microbial World and You Classification of Microbes Taxonomic Hierarchy Each name is Latinized There is a specific way to write each name. Homo sapiens The first word is capitalized Name is in italics Homo sapiens H. sapiens