Saturday, 26 December 2015

Classic microbiology: Louis Pasteur


Few people have saved more lives than Louis Pasteur. The vaccines he developed have protected millions. His insight that germs cause disease revolutionised healthcare. He found new ways to make our food safe to eat.

Pasteur was the chemist who fundamentally changed our understanding of biology. By looking closely at the building blocks of life, he was at the forefront of a new branch of science: microbiology.

Louis Pasteur was probably the greatest biologist of the nineteenth century. He developed the germ theory of disease, which was a significant breakthrough in medicine that ultimately improved the health of everyone on the planet. He was also able to prove that life itself did not "spontaneously come into being" through a series of experiments using a sterilized flask. He successfully showed that life can only be generated from existing life, thus closing debate - so he thought - that had obsessed science and theology for a long time (though current ideas and successes in the field of "creating life" has re-opened the issue).

Pasteur also showed that fermentation - a process used in baking and brewing - was caused by microorganisms. As a result of this work he went on to develop the process for sterilizing milk and this was named after him - pasteurization.

He is also credited with the development of vaccines, most notably for rabies and anthrax. Pasteur was keen to develop vaccines for other diseases. He turned his attention to anthrax. Anthrax was fatal to humans, and could wipe out entire populations of farm animals. Anyone who could prevent the disease would not only save lives, but also stood to make money. German doctor Robert Koch had already found the bacteria that caused the disease. Now Pasteur announced he'd discovered a vaccine, and successfully immunised 31 animals – although recent studies of his notebooks have revealed he exaggerated how much original work he did; he'd actually drawn on other people's findings.

 In addition, he identified and eliminated disease in silkworms. He was also interested in the idea of panspermia that was promoted by Lord Kelvin in 1871, and went on to examine the Orgeuil meteorite for signs of life.

Posted by Dr. Tim Sandle