🔴 DESCUBRIMIENTO DE LOS MICROORGANISMOS Y TEORÍA DE LA GENERACIÓN ESPONTÁNEA | Microbiología 🔬

Microorganisms: The Invisible World

Early Suspicions of Microorganisms

• Researchers suspected the existence of microorganisms before they could be seen, proposing that diseases were caused by invisible living creatures.

Anthony van Leeuwenhoek's Discoveries

• In 1673, Anthony van Leeuwenhoek created a simple microscope with a convex lens mounted on brass, allowing him to observe microorganisms for the first time.

• His microscope achieved up to 200x magnification and enabled detailed descriptions of microscopic life in water droplets.

• Van Leeuwenhoek referred to these organisms as "animalcules," which we now recognize as protozoa and bacteria.

Controversy Over Spontaneous Generation

• The discovery sparked controversy; many scientists believed in spontaneous generation—the idea that life could arise from non-living matter. Aristotle supported this view regarding simple invertebrates.

• Francesco Redi challenged this notion through experiments demonstrating that maggots on decaying meat came from fly eggs, not spontaneous generation.

Experiments Challenging Spontaneous Generation

• Redi's experiment involved three jars: one sealed, one covered with gauze, and one open; only the open jar produced maggots due to fly access.

• Subsequent experiments by John Needham and Lazzaro Spallanzani tested boiled meat extracts for microbial growth, leading to further debate about air's role in contamination.

Pasteur's Groundbreaking Work

• Between 1834 and 1859, various experiments confirmed that air could carry germs but also suggested it was necessary for microbial growth under certain conditions. []

• Louis Pasteur ultimately resolved the debate over spontaneous generation with his swan-neck flask experiment, showing no microbial growth when dust was trapped in the neck while exposed to air.