Untitled

• Microbiology is the study of organisms too small to be seen without magnification.
• The term microbiology is derived from the Greek words mikros (small), bios (life), and logos (study).
• Microorganisms include bacteria, viruses, fungi, protozoa, helminths, and algae.

Taxonomy and Classification

• Living things classification organizes organisms based on shared characteristics.
• The classification system from broadest to specific is: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.
• Domain classification is the highest taxonomic level, divided into Archaea, Eukarya, and (Eu)Bacteria.

Domains of Life

• The three domains of life are Bacteria, Archaea, and Eukarya.
• Bacteria are true bacteria.
• Archaea are bacteria living in extreme conditions such as high salt or heat.
• Eukarya have a nucleus and organelles.

Six Kingdom Classification

• Organisms are broadly classified into two categories: Prokaryotes and Eukaryotes.
• Prokaryotes are very tiny simple cells with no true nucleus or organelles.
• Eukaryotes are larger, more complex cells with a nucleus and numerous organelles.
• The six kingdoms of life are: Archaebacteria, Eubacteria, Plants, Fungi, Protists, and Animals.

Cellular vs. Acellular Microorganisms

• Microorganisms can be cellular or acellular.
• Cells are either Eukaryotic with a nucleus and intracellular organelles, or Prokaryotic with neither.
• Acellular microorganisms do not have cells.

Importance & Scope of Microbiology

• Microbiology has an extensive scope applicable in genetics, biochemistry, food sciences, ecology, immunology, agriculture, and medicine.

Origins of Microorganisms

• Bacteria-like organisms have existed on Earth for about 3.5 billion years.
• Prokaryotes have simple cells with no pre-nucleus.
• Eukaryotes have complex cells with a true nucleus.

Microbial Structure

• Prokaryotes are microscopic, unicellular organisms lacking nuclei and membrane-bound organelles.
• Eukaryotes are unicellular or multicellular with a nucleus and membrane-bound organelles.
• Viruses are acellular, parasitic particles made of nucleic acid and protein.

Microbial Diversity

• Microbes include Bacteria, Fungi, Algae, Viruses, Protozoa, and Helminths.

Microbial Dimensions

• Microbes vary significantly in size from macroscopic to requiring special microscopes

Microbes in Ecosystems

• Microbes are integral to the flow of energy and nutrients in ecosystems.
• Photosynthesis is the light-fueled conversion of carbon dioxide into organic material.
• Decomposition is the breakdown of dead matter and wastes into simple compound

Human Use of Microorganisms

• Biotechnology involves using living organisms to produce foods, drugs, and vaccines.
• Genetic engineering manipulates the genes of organisms to create new products.
• Bioremediation uses living organisms to solve environmental problems.

Microbial Applications

• Microorganisms have major effects on animal health, human health, ecosystem health, water, waste, agriculture, natural resources, food, biotechnology, industry and bioenergy.

Microorganism Lifestyles

• Most microorganisms live freely being harmless and often beneficial.
• Some microorganisms are parasites, living in or on a host organism and causing damage.

Microbes & Infectious Diseases

• Pathogens are microbes that cause harm and disease.
• Nearly 2,000 different microbes can cause diseases.
• There are approximately 10 billion new infections and 12 million infection-related deaths worldwide annually.

Historical Foundations

• Over 300 years there have been thousands of microbiologists.
• Key discoveries include: microscopy, the scientific method, medical microbiology, and microbiological techniques.

Scientific Method

• The scientific method explains natural phenomena.
• A hypothesis is made and then tested through experiment and analysis.
• Results are published and replicated.
• A hypothesis becomes a theory after surviving rigorous scrutiny and accumulating supporting evidence.
• A compelling theory is established in a scientific law or principle

Discovery of Spores and Sterilization

• John Tyndall and Ferdinand Cohn discovered heat resistance of certain microbes.
• Cohn identified heat-resistant bacterial endospores.
• Sterility requires the elimination of all life forms, including endospores and viruses.

History of Microbiology: Antonie van Leeuwenhoek (1632-1723)​

• Antonie van Leeuwenhoek was a Dutch linen merchant.
• He is regarded as the Father of Bacteriology and Protozoology.
• Leeuwenhoek was the first to observe living microbes.
• He made single-lens magnifiers that could magnify specimens up to 300x.

History of Microbiology: Spontaneous Generation​

• Spontaneous generation is the early belief that life arises from nonliving matter.
• Louis Pasteur disproved spontaneous generation with the Theory of Biogenesis.
• The Theory of Biogenesis states living things can only arise from other living things.

History of Microbiology: The Germ Theory of Disease

• The Germ Theory of Disease states that diseases are caused by microbes growing in the body, not by bad character, sins, or poverty.
• Louis Pasteur and Robert Koch greatly contributed to the Germ Theory.

History of Microbiology: Louis Pasteur (1822-1895)

• Louis Pasteur showed that microbes cause fermentation and spoilage.
• He is regarded as the "Father of Microbiology and Immunology".
• Pasteur disproved spontaneous generation.
• Pasteur developed pasteurization.
• Pasteur demonstrated the Germ Theory of Disease.

History of Microbiology: Robert Koch (1843-1910)

• Robert Koch was a German microbiologist.
• Koch established Koch's postulates, which are a sequence of steps to verify the germ theory.
• He identified the cause of anthrax, tuberculosis (TB), and cholera.
• Koch developed pure culture methods/techniques.
• Robert Koch was awarded the Nobel Prize in medicine in 1905.

History of Microbiology: Alexander Flemming

• Alexander Fleming was a Scottish doctor and biochemist born in 1881.
• He contributed to knowledge about antibiotic penicillin.
• He was awarded the Nobel Prize in 1945.
• Fleming worked on antimicrobial substances non-toxic to the human body and toxic to microbial bodies.
• He discovered the bacteriolytic substance lysosome from animal tissue.

Taxonomy

• Taxonomy is the science of organizing, classifying, and naming living things.
• Carl von Linné created the formal taxonomic system.
• Taxonomy concerns classification the orderly arrangement of organisms into groups, nomenclature assigning names, and identification determining and recording traits of organisms.

Assigning Specific Names

• Binomial nomenclature is used to assign a scientific name with a genus and species.
• The genus name is always capitalized.
• The species name is always lowercase.
• Both names are always italicized or underlined.

Origins and Evolutions

• Phylogeny is the natural relatedness between groups of organisms.
• Evolution is the gradual change in living things over long periods.
• New species originate from pre-existing species.
• Related organisms share similar features from common ancestors.
• Evolution usually progresses towards greater complexity.
• Characteristics favoring survival are kept and less beneficial ones are lost.