Lecture 2 1.5 The Historical Roots of Microbiology 1.6 Microbial Diversity and the Advent of Molecular Microbiology 2. 1 Elements of cell and viral structure 2.2 Arrangement of dna in Microbial Cells 2, 3 The tree of life
Lecture 2 • 1.5 The Historical Roots of Microbiology • 1.6 Microbial Diversity and the Advent of Molecular Microbiology • 2.1 Elements of Cell and Viral Structure • 2.2 Arrangement of DNA in Microbial Cells • 2.3 The Tree of Life
Louis pasteur -1860 Where do the microorganisms come from? Spontaneous generation? Air forced out open end (a) Nonsterile liquid Neck of flask Liquid sterilized poured into drawn out in y heating flame Heat was used to kill the microorganisms in the liquid
Louis Pasteur ~1860 Where do the microorganisms come from? Spontaneous generation? Heat was used to kill the microorganisms in the liquid
Dust and microorganisms Open trapped in bend end :(:动 Long time (b) Liquid cooled Liquid remains slowly sterile for many years When dust was prevented from reaching the sterilized liquid nor microorganisms grew in the liquid
When dust was prevented from reaching the sterilized liquid, nor microorganisms grew in the liquid
Short time Flask tipped so Microorganisms microorganism-laden grow in liquid dust contacts sterile liquid Contact with dust resulted in growth of microorganisms in the liquid -disproved spontaneous generation
Contact with dust resulted in growth of microorganisms in the liquid -disproved spontaneous generation
Robert Koch, 1870s proof that microorganisms can cause disease germ theory of disease Diseased Health anima animal Postulate 1 The suspected pathogenic Observe organism should be presentEd bo0°-● blood /tissue in all cases of the disease under the and absent from healthy animals Suspecte Red blood cell pathoger Anthrax, caused by bacillus anthracis Organism present in the blood of all diseased animals -cause or result of the disease? gure 1.12
Robert Koch, 1870s --Proof that microorganisms can cause disease -“germ theory of disease” Anthrax, caused by Bacillus anthracis Organism present in the blood of all diseased animals -cause or result of the disease? Figure 1.12