Landmark Discoveries in Microbiology

Aristotle quoted the given statement in description of the cellular structure of living things back in the 4^th century B.C.

Edward Buchner published the first evidence of a cell-free fermentation process using extracts isolated from yeast. This discovery refuted Pasteur's claim that fermentation requires the presence of live cells.

The period between 1865-1882 is known as the golden era of microbiology because all the pioneering works of Louis Pasteur, Robert Koch and Lister etc. made the most important discoveries and laid the foundation of microbiology.

Louis Pasteur introduced the terms aerobic and anaerobic in describing the growth of yeast at the expense of sugar in the presence or absence of oxygen. He observed that more alcohol was produced in the absence of oxygen when sugar is fermented, which is now termed the Pasteur effect.

Gerhard Henrik Armauer Hansen discovered Mycobacterium leprae in 1873. This was the first time that a chronic infectious disease in humans was shown to be related to a bacillus.

The first prototype of the present day compound microscope was given by Zacharias Janssen by adding one more lens to the telescope.

Schwann and Shculze are known for introducing cotton plugs to prevent entry of microorganism in sterile medium.

In 1942, Thomas Anderson and Salvador Luria demonstrated that an E. coli T2 phage has a head and a tail. They photographed bacteriophages with the aid of an electron microscope.

Fluctuation analysis given by Salvador Luria and Max Delbruck is associated with mutation rate. Fluctuation analysis shows that resistance in bacteria occurs before exposure to the phage and argues against the adaptation hypothesis of mutations.

Haemophilus influenzae was the first microorganism whose genome was sequenced. In 1995, Craig Venter, Hamilton Smith, Claire Fraser and colleagues at TIGR (The Institute for Genomic Research) elucidated the first complete genome sequence of Haemophilus influenzae.

George Beadle and Edward Tatum in 1941 using the fungus Neurospora crassa established the one gene one enzyme concept. According to it, particular genes are expressed through the action of correspondingly specific enzymes.

This is the correct chronological sequence. In 1936, J. D. Bernal, F. C. Bauden, N. W. Pirie isolated ribonucleic acids from TMV. In 1938, Max Theiler's vaccine against yellow fever was proved successful in field trials. In 1939, E. L. Ellis and Max Delbruck established the concept of one-step viral growth cycle for a bacteriophage active against E. coli and in 1940, Helmuth Ruska used an electron microscope to obtain the first pictures of a virus.

In 1889, Kitasato obtained the first pure culture of the strict anaerobic pathogen, the tetanus bacillus Clostridium tetani.

In 1875, Cohn published an early classification of bacteria, using the genus name Bacillus for the first time.

John Tyndall developed a process of intermittent heating to kill spores known as Tyndallization. Tyndallization essentially consists of heating the substance to boiling point (or just a little below boiling point) and holding it there for 15 minutes, three days in succession. After each heating, the resting period will allow spores that have survived to germinate into bacterial cells; these cells will be killed by heating the next day.