history of microbiology Flashcards
who was the first person to observe and accurately describe bacteria
Antony van Leeuwenhoek (1632-1723)
define spontaneous generation
the belief that living organisms could develop from nonliving matter
who first opposed the theory of spontaneous generation
Francesco Redi
what did francesco redi do to oppose spontaneous generation theory
he did some fun experiments with meat in an uncovered jar, covered, and partially covered (permeable layer)
what were the findings of francesco redi’s experiments
found that maggots only arose in the uncovered and partially covered flasks = they arose from the eggs of flies that were attracted to the meat rather than the meat itself
who came after francesco redi
john needam
what did john needam believe
spontaneous generation could occur under the right conditions
describe john needam’s experiment + findings
had a broth that was heated, then left open as it cooled, he waited, and then observed growth
who came after john needam
lazzaro spallanzani
what did lazzaro spallanzani believe
he believed that the growth from john needam’s experiment was due to the flask being left open (ie experimenter error)
describe lazzaro spallanzani’s experiment
replicated john needam’s (with open flask) and also did it with a closed flask.
open flask= growth, closed flask=no growth
after all the experiments (redi, needam, spallanzani), what did critics have to say
they suggested that heating the air in the sealed flasks destroys the ability of the air to support life
who settled the spontaneous generation controversy
louis pasteur
describe pasteur’s experiment
poured beef broth into a long-necked flask, bent it into an S-shape, boiled it, then observed that there was no growth even though it was exposed to air
summarize pasteur’s findings
microbes are found in nonliving material and they can be destroyed by heat
