MICROBIOLOGY History and Types of Cells Chapter 1 Nester 2nd Ed.

History u Cartoons u Ancient descriptions of diseases Chinese writings Egyptian papyrus writings Bible u Microorganisms seen about 325 years ago. u Microbiology is only 130 years old.

Anton van Leeuwenhoek u Drapery merchant u Made ground glass lenses - magnified 300X u Figure 1.2 p. 3 simple microscope u Figure 1.1 p. 3 drawings of microorganisms u Described animalcules u Question: How did these organisms originate?

Francesco Redi - late 1600’s u Disproved spontaneous generation for visible organisms u Figure - Classical Jar Experiment u Gauze did not prevent microorganisms in the air from entering the jars. u The meat in the gauze covered jar rotted but did not produce maggots.

John Needham u Made broths (infusions) of many things hay, beef and chicken in other words - soup u Heated broths in flasks; then sealed flasks u All his broths still be came turbid (cloudy). u Microorganisms “got in” the flasks. u Pro-spontaneous generation

Father Spallanzani ’s u Boiled his infusions longer u Sealed flasks u Got no growth u Anti-spontaneous generation u Had no real explanation

None of these people considered: u The flasks were improperly sealed. u There were organisms in the air. u Boiling might not kill all organisms. u Standardization would be beneficial.

Louis Pasteur u He did the classic experiment that refuted spontaneous generation. u Figure 1.4 p. 5 swan-necked flask u He trapped microorganisms on a cotton plug and observed them microscopically. u An organism, on a cotton plug dropped in sterilized infusion, caused the broth to become turbid.

John Tyndall u He provided a logical reason for the discrepancies of previous workers. u He heated infusions for varying lengths of time. u He proposed that there were heat resistant life forms. u Endospores were discovered the same year.

Cell Theory u Schleiden u Schwann u Virchow u All organisms are composed of cells. u The cell is the fundamental unit of life. u All cells come from preexisting cells.

Similarities of All Cells u Structure - genetic material, plasma membrane, cytoplasm u Replicate exact copies of DNA u Have genetic instructions for synthesis of its parts u Obtain and use energy

Prokaryote versus Eukaryote u Prokaryote = pre-nucleus u Eukaryote = true nucleus u Table 1.3 comparison of these two groups

Prokaryotes u Eubacteria true bacteria diverse group rigid cell wall contains the pathogens Table 1.4 major groups u Archaea primitive bacteria diverse group variable cell wall now thought to be the most common bacteria on earth found in many environments

Prokaryotes u Both Eubacteria and Archaea are similar by microscopy and how they are classified. u Eubacteria and Archaea differ biochemically. RNA’s Enzymes Nutritional requirements Environments where they grow

Intermediate Cells u Figure 1.7 p. 12 Giardia intestinalis nucleus no mitochondria u Figure 1.8 p. 13 Gemmata obscuriglobus membrane-bound nuclear body no other membrane-bound organelles

Other Members of the Microbial World - Eukaryotes u Algae unicellular or multi-cellular Figure 1.10 p. 15 u Fungi usually multi-cellular some single cell forms Figure 1.11 p. 15

Other Members of the Microbial World - Eukaryotic u Protozoa single cells Figure 1.12 p. 16 u Table 1.5 p. 15 comparison of algae, fungi, protozoa

Other Members of the Microbial World - Non-living u Viruses nucleic acid plus protein and lipid Figure 1.13 p. 17 u Viroids naked nucleic acid Figure 1.14 p. 17

Other Members of the Microbial World - Non-living u Prions self replicating proteins may be weird viruses or viroids replication is a mystery u Table 1.6 p. 16 comparison of viruses, viroids, prions

Sizes of Microorganisms u Figure 1.16 p. 18 comparison of sizes u Perspective 1.3 p. 12 largest prokaryote

Nomenclature - Naming u Binomial system - two names u similar to the system developed by Carl von Linne changed his own name to Carolus Linneus u K, P, C, O, F, G, S, V

Nomenclature u Genus - 1st word is capitalized u Species - 2nd word is lower case Escherichia coli or E. coli Legionella pneumophila or L. pneumophila u Member of the same species can vary in minor ways strains or varieties E. coli K-12, E. coli ML