Who discovered the process of fermentation?

Correct answer: (d) Louis Pasteur

Explanation

Louis Pasteur showed around 1857 that fermentation is caused by living micro-organisms: yeast turns sugar into alcohol, and bacteria turn it into lactic acid. This work led to his germ theory of disease and to pasteurisation.

• Robert Koch found the bacteria that cause tuberculosis, cholera and anthrax, and set out Koch's postulates.
• Joseph Meister was the boy who, in 1885, became the first person to receive Pasteur's rabies vaccine.
• Ernst Haeckel was a zoologist who coined the word "ecology".