BASICS OF MICROBIOLOGY

• Microbiology


  A specialized area of biology that deals with living things ordinarily too small to be seen with the naked eye
• Microorganisms or microbes

  • Germs
  • Viruses
  • Agents
  • "Bugs"
• Major groups of microorganisms


  • Cellular: Bacteria, Archaea, Fungi, Protozoa
  • Helminths: Not technically a microorganism, can cause human infection
  • Noncellular: Viruses, Prions
• Microbes


  • They reproduce so rapidly and can quickly grow large populations in the laboratory
  • They cannot be seen directly, must be analyzed through indirect methods in addition to using microscopes
• Public Health Microbiology and Epidemiology

  Monitor and control health and the spread of diseases in communities
• Immunology


  Studies the complex web of protective substances and cells produced in response to infection or cancer, includes vaccination, blood testing, and allergy
• Immunologists


  Also investigate the role of the immune system in autoimmune diseases
• Industrial Microbiology


  Safeguards our food and water, Biotechnology, Microbes can be used to create large quantities of substances
• Substances microbes can be used to create

  • Amino acids
  • Beer
  • Drugs
  • Enzymes
  • Vitamins
• Agricultural Microbiology

  Relationships between microbes and farm animals and crops
• Plant Specialists in Agricultural Microbiology

  • Plant diseases
  • Soil fertility
  • Nutritional interactions
• Animal Specialists in Agricultural Microbiology

  • Works with infectious diseases
  • Other associations animals have with microorganisms
• Areas of Environmental Microbiology

  • Aquatic Microbiology: Microbes in the earth's surface water
  • Soil Microbiology: Microbes in terrestrial parts of the planet
  • Geomicrobiology: Microbes in the earth's crust
  • Astrobiology: Study of microbial and other life in places off of our planet
• Microbes have shaped the development of earth's habitats and the evolution of other life forms for billions of years
• Soon after the earth was formed, the first ancient cells formed
• Eukaryotes appeared more than a billion years later
• Eukaryotes


  Cells that contain a nucleus
• Akaryotes


  Cells without a nucleus, including Bacteria and Archaea
• Bacteria


  • They are ubiquitous, meaning they can be found nearly everywhere, from deep in the earth's crust to polar ice caps, oceans, and inside the bodies of plants and animals
• Evolution


  The accumulation of changes that occur in organisms as they adapt to their environments
• Theory of Evolution


  A label for the well-studied and well-established natural phenomenon of evolution, which is documented every day in all corners of the planet and is testable by science
• Microbes are deeply involved in the flow of energy and food through the earth's ecosystems
• Photosynthesis


  1. Bacteria invented photosynthesis long before the first plants appeared, first as a process that did not produce oxygen, then evolved into oxygenic photosynthesis

  2. The production of oxygen by microbes allowed species diversification
• Decomposition


  Involves the breakdown of dead matter and wastes into simple compounds that can be directed back into the natural cycles of living things, accomplished by bacteria and fungi
• Humans have been using microorganisms for thousands of years to improve life and even shape civilizations, such as using yeast for bread, wine, and beer, and using moldy bread to treat wounds in ancient Egypt
• Human uses of microorganisms

  • Biotechnology
  • Recombinant DNA technology
  • Bioremediation
• Pathogens


  Any agent such as virus, bacterium, fungus, protozoan, or helminth that causes disease
• Malaria kills about 450,000 people every year worldwide, and is caused by a microorganism transmitted by mosquitoes. The most effective prevention is the use of bed nets
• We are witnessing an increase in the number of new (emerging) and older (reemerging) infectious diseases, such as SARS-COV-2, Ebola, AIDS, Hepatitis C, and viral encephalitis, which cause severe mortality and morbidity
• Polio, leprosy, and parasitic worm diseases have largely been eradicated
• Examples of noninfectious diseases linked to microbes

  • Helicobacter pylori and gastric ulcers
  • Coxsackievirus linked with diabetes and schizophrenia
  • Chronic microbial infections linked to multiple sclerosis, obsessive compulsive disorder, coronary artery disease, and obesity
• Researchers are currently researching whether Alzheimer's disease is related to microbes found in the brains of people with the disease
• An increasing number of patients with weakened immune systems are subject to infections by common microbes not pathogenic to healthy people, and drug-resistant microbes also contribute to the increase in infectious disease
• Three basic cell lines that appeared during evolutionary history

  • Archaea
  • Eukarya
  • Bacteria
• The majority of microorganisms are single-celled, including all bacteria and archaea, and some eukaryotes, while some microorganisms are multicellular, such as helminths and some fungi
• Bacterial and archeal cells

  About 10x smaller than eukaryotic cells, lack organelles
• Eukaryotic cells

  Contains organelles like the nucleus, mitochondria, and chloroplasts
• Viruses

  Composed of small amounts of hereditary material (either DNA or RNA) wrapped in a protein covering that is sometimes enveloped by a protein-containing lipid membrane
• Prions


  Small proteins folded in intricate ways which sometimes behave like microorganisms and are transmitted from one human to another
• Certain foods spoiled, became inedible, or caused illness, and the black plague and smallpox were believed to be caused by some kind of transmissible matter, but there was a belief in spontaneous generation