1. Science of Microbiology dates back 250 years
2. But MycoBacterium tuberculosis DNA has been discovered in 3000 years old Egyptian mummies
3. The science started by invention of Microscope in 1660 by robert hooke
   1. Micrographia is a book written by him that describes Microscopic world
   2. His study on thin slices of cork was the most famous microscopical observation
   3. Coined the word Cell
   4. Marked the beginning of Cell Theory (All living things are composed of cells)
4. Micrographia inspired Anton Van Leeuwenhook
   1. No University degree or language skills
   2. Passion to grind lenses and made simple microscopes
   3. Discovered bacteria and protozoa
5. Discovery of Van Leeuwenhook led to Proposing of SPONTANEOUS GENERATION
   1. Spontaneous Generation Theory: Life arise spontaneously from nonliving organic mater
   2. Evidences to this Theory
      1. John Needham: Heated nutrient fluids and poured them into covered flasks. were teeming with Micro Organisms when cooled
      2. Lazzaro Spallanzani disapproved Needhom's theory because he thought the fluids were not boiled long enough But he also thought the source of Micro organisms was from the air as the flasks were covered only
6. BIOGENESIS THEORY
   1. Radulf Virchow challened the Spontaneous Generation Theory with this Theory
   2. LIving cells can arise only from preexisting living cells
7. Spontaneous Generation vs Biogenesis issue was finally resolved in 1861 by Louis Pasteur's experiment
   1. A
      1. filled several short necked flasks with Boiled broth and boiled the content , some of them sealed and some left opened
      2. The ones Sealed after Boiling: No MicroOrganisms
   2. B
      1. Placed broth in open-ended long necked flasks bent into S shape and boiled the contents on the flasks and cooled, Unsealed them , No signs of life
      2. Conclusions
         1. 1.Air passed through but curved neck trapped airborne Microorganisms
         2. 2,Microbial life can be present every where and can be destroyed by heat
         3. 3.Methods can be devised to block the access of airbone microorganisms to nutrient environments
         4. Basis of ASPETIC TECHNIQUES