General Microbiology - MCB 201 PDF

GENERAL MICROBIOLOGY- MCB 201 Scope & History of Microbiology  Nature of Science Science is a systematized knowledge developed through the application of the scientific method Observations (objective vs. subjective) Formulate hypothesis Test hypothesis with controlle...

GENERAL MICROBIOLOGY- MCB 201 Scope & History of Microbiology  Nature of Science Science is a systematized knowledge developed through the application of the scientific method Observations (objective vs. subjective) Formulate hypothesis Test hypothesis with controlled experiments Accept, revise or reject hypothesis Microbiology is the study of microorganisms, which are organisms that are invisible to the naked eye. Classification of Microorganisms The 5 major groups of microorganisms: Bacteria, algae, fungi, protozoa, and viruses. Other smaller groups: prions and viroids. The one property that links these groups together is their very small size. Some organisms studied by microbiologists can be viewed without the aid of amplification [bread molds (fungus) and filamentous algae]  Why study Microbiology? 1. Impact on Human Health 2. Balance of Nature - food source, play a role in decomposition, help other animals digest grass (cattle, sheep, termites). 3. Environmental benefits – provide safe drinking water; development of biodegradable products; use bacteria to clean up oil spills, etc. – called bioremediation 4. Industrial purposes-foodstuffs (cheese, bread, wine), antibiotics, insulin, genetic engineering 5. Agricultural benefits - research has led to healthier livestock and disease-free crops.  Important and beneficial biological functions of Microbes: 1. Food Industry: Many important foods and beverages are made with microbes: Beverages,Bread, Vinegar, Soy sauce, Cheese, Pickles, olives, sauerkraut, Yogurt, Buttermilk, Sour cream,Coffee, Chocolate, sausages 2. Genetic Engineering: Recent advances in gene splicing allow us to design recombinant microbes that produce important products: Human growth hormone (Dwarfism), Insulin (Diabetes), Blood clotting factor (Hemophilia), Recombinant vaccines, Hepatitis A and B vaccines, Human hemoglobin (Emergency blood substitute), Taxol (Breast and ovarian cancer), Erythropoietin (Anemia), Monoclonal antibodies (Disease diagnosis and prevention). 3. Medical Research: Microbes are well suited for biological and medical research for several reasons: Relatively simple and small structures, easy to study. Genetic material is easily manipulated. Can grow a large number of cells very quickly and at low cost. Short generation times make them very useful to study genetic changes. 4. Medicine: Many antibiotics and other drugs are naturally synthesized by microbes: Penicillin is made/produced by a mold. 5. Digestion: Animals have microorganisms in their digestive tract, that are essential for digestion, vitamin synthesis, and overall health. Cellulose digestion (termites, cows, rabbits, etc.) Vitamin K and B synthesis in humans Prevent the overgrowth of pathogenic bacteria and yeast 6. Photosynthesis: Algae and some bacteria capture energy from sunlight and convert it to food, forming the basis of the food chain. 7. Decomposers: Many microbes break down dead and decaying matter and recycle nutrients that can be used by other organisms. 8. Nitrogen Fixation: Some bacteria can take nitrogen from air and incorporate it into soil. Fields in Microbiology Anton van Leeuwenhoek (1632 – 1723): A dutch merchant, in 1673 was the first person to develop a simple microscope, observe live organisms which he called “animalcules” (bacteria, protozoa) and also, the the first to report microorganisms at 50-300x magnification. He is known as “the father of Microbiology”. Robert Hooke (1635-1703): An Englishman, mechanic and tinker. In 1665, he built a compound light microscope and used it to observe thin slices of cork.He coined the word ‘cell’ and brought about the Scientific revolution. His discovery led to the formulation of the cell theory, which states that cells are the basic organizational unit of all living things. He created the first working microscope and was the first to observe dead cells. Louis Pasteur (1822-1895): He was the first to demonstrate that infectious diseases are caused by microbes, disproved the concept of spontaneous generation and developed the process of pasteurization (a process used to kill microorganisms responsible for spoilage). He also developed vaccines for the treatment of diseases, including rabies, in animals and humans. 1858-Pasteur proved that living cells arise only from preexisting living cells. In other words, life only comes from life.  Robert Koch (1843–1910): In 1876, he established that microbes can cause disease. He devised criteria for establishing a causal link between a microbe and a disease and these are now known as Koch’s postulates.  Koch’s postulates 1. The microorganism must be present in every case of the disease and absent from healthy organism. 2. The suspected microorganism must be isolated and grown in pure culture. 3. When the microorganism is inoculated into a healthy host, the same disease condition must result. 4. The same microorganism must be re-isolated from the experimentally infected host. Early history of Microbiology  Who is the father of Microbiology? a. Leeuwenhoek b. Koch c. Pasteur State Koch’s postulates.