SPONTANEOUS GENERATION Vs BIOGENESIS

Francesco Redi (1626-1697):- Most renowned for his experiment  on "spontaneous generation" – which is also recognized as Aristotelian abiogenesis. At the time, prevailing wisdom was that maggots made naturally from rotting meat. He did a research in which he placed meat in a jar covered with gauze .Attracted by the odor of the meal flies laid eggs on the covering form where the egg maggots developed. From the experiment it was proved that the origin of the maggots was the flies, not the meals.

John Needham (1713-1781):-Spontaneous generation was first proved by John Needham. In his experiment he heated pieces of meat to destroy pre existing organism by placing them in open flasks .On the surface he found micro organisms in colonies from the experiment, He came in decision that organisms can be originated spontaneously.

Lazaro Spallanzani (1729-1799):- . By this experiment he disproved the theory of spontaneous generation given by John Needham. He boiled beef broth in flasks for an hour and then sealed the flasks. No microscopic organisms appeared following incubation .But Needham strongly opposed him because Needham insisted that, air was important to the spontaneous production of microscopic beings.

Franz Schulze (1815-1873):- Theodor Schwan (1810-1882):-His work was similar to Franz Schulze. In his experiment he passed air into his flasks through red hot tubes. In the experiment microbes did not appear in the broth, Because existing microbes in the air was killed by heat.

·        Spontaneous generation:

·        Louise Pasteur(1820-1910): He performed a series of definite experiment to proof the theory of biogenesis. In his experiment he used flasks with long ,cured stems resembling swan necks or goose neck , which were filled with   broth and heated. Air could pass freely through the open necks, but no microbes  appeared in the solution. Dust particles and microbes ad settled in the u-shaped section of the curved tube but did not read the broth.By this experiment he completely disproved the theory of biogenesis.

·        FERMENTATION:

       Louis Pasteur (1822-1895):- He established the germ theory of fermentation.  Fermentation of fruits and grains, resulting in alcohol was brought about by microbes this was found by him. He found microbes of different sorts by examining many batches of ‘ferment’ Pasteur suggest that the undesirable types of microbes must be removed by heating. He found that holding the juices at  temperature of 62.8 degree c (145 degree F)for half an hour did the job.
RENIN–ANGIOTENSINPATHWAY