April 13, 2015

#04-004: Louis Pasteur, Father of Microbiology

black-and-white photo of a scowling, mustached man in a bow tie and dark suit
Louis Pasteur

Note: If your milk isn't "Pasteurized," you'd probably be better off not drinking it! Learn about the French scientist who lent his name to the process.

Get Ready: Do you think much about germs--bacteria and viruses and the like? How important are they?

Not so long ago, people--even scientists--had some strange ideas about biology.

They didn't believe in germs. But we now know that many common illnesses are the result of attacks on our bodies by bacteria, viruses, and other living things too small to be seen. These are called "microorganisms," and the study of them is "microbiology."

Even as late as the mid-19th century, scientists also believed that life could be created out of nothing. For example, if one leaves meat out, and worms grow in it, people thought the worms grew from the dead meat itself; they didn't realize it was because flies had left their eggs there. This wrong belief is called "spontaneous generation."

A Frenchman named Louis Pasteur (1822-1895) is largely responsible for proving these ideas wrong. Born to a working-class family, he was a poor student, more interested in fishing and making drawings than in studying.

He became a teacher after completing his B.A. studies in 1840, and began advanced studies in science and mathematics. After having to take several failed exams over, he finally began his career as a professor of physics, and, later, chemistry.

Through various experiments, Pasteur proved that life could only come from life--that spontaneous generation couldn't happen--and that microorganisms were the cause of some otherwise mysterious happenings.

For example, he would set up three containers. One was tightly covered, and the material inside was sterilized. A second container had sterile material, but was left open. A third would be sealed, but with unsterilized material inside.

Can you guess what happened? Nothing grew in the first container, but various moulds, worms, and other life forms grew in the other two. This proved that living things could only develop if microorganisms could enter from outside, as in the second container, or were there already and not killed, as in the third.

This was a great discovery, and was useful in keeping foods safe for people to eat and drink. Today, milk and other foods are protected by heating them mildly, just enough to kill harmful microorganisms without damaging the food. The process is known by this scientist's name: pasteurization.


Read more: https://en.wikipedia.org/wiki/Louis_Pasteur

Practice: Match the term to its definition below:

  1. biology
  2. experiments
  3. germs
  4. harmful
  5. microbiology
  6. microorganisms
  7. moulds
  8. pasteurization
  9. spontaneous generation
  10. sterile, sterilized

  1. the scientific word for living things too small to be seen
  2. the study of microorganisms
  3. a common word for microorganisms
  4. the false idea that life could be created out of nothing
  5. not helpful; dangerous
  6. the process of killing bacteria and other microorganisms using mild heat
  7. fungi that grow on unclean surfaces
  8. free from microorganisms
  9. the study of all living things
  10. scientific tests to find out if something is true

Answers are in the first comment below.

Submitted to the Shenzhen Daily for April 13, 2015

This lesson received 2 visits on my old site between April, 2016, and August, 2021.

1 comment:

  1. Answers to the Practice: 1. i; 2. j; 3. c; 4. e; 5. b; 6. a; 7. g; 8. f; 9. d; 10. h