History of microorganisms' discovery

Anton van Leeuwenhoek was one of the first people to observe microorganisms, using a microscope of his own design, and made one of the most important contributions to biology.^[22] Robert Hooke was the first to use a microscope to observe living things; his 1665 book Micrographia contained descriptions of plant cells.

Before Leeuwenhoek's discovery of microorganisms in 1675, it had been a mystery why grapes could be turned into wine, milk into cheese, or why food would spoil. Leeuwenhoek did not make the connection between these processes and microorganisms, but using a microscope, he did establish that there were forms of life that were not visible to the naked eye.^[23][24] Leeuwenhoek's discovery, along with subsequent observations by Lazzaro Spallanzani andLouis Pasteur, ended the long-held belief that lifespontaneously appeared from non-living substances during the process of spoilage.