Answer to Question #131508 in Microbiology for Neel Thakkar

Question

In redi’s meat experiment microorganisms are not grown then why in swan

neck microorganisms are grown automatically while both are in contact with

air?

2) Why swan neck experiment is considered as theory and challenged

spontaneous generation? 

Answer 1

1) The swan neck slows down the motion of air through the tube. Particles in the air and bacteria become trapped on moisture on its inner surfaces. Therefore, sterile liquid in the vessel itself remains sterile as long as the liquid does not contact the contaminated liquid in the tube.

2) Louis Pasteur's 1859 experiment settled the question of spontaneous generation. Louis Pasteur boiled a meat broth in a swan neck flask. The bend in the neck of the flask prevented falling particles from reaching the broth, while still allowing the free flow of air.