The Size of Microbes
Bacteria are comparatively small. The single cell of many bacteria is about 40 millionth of an inch (1 u) in diameter.
There are however, some types of bacteria that may be 50 or more times larger than this.
Due to their small size, bacteria cannot be seen with naked eye, and when evidence of their growth can be seen, such as when slime forms on meat, the organisms will have multiplied to a very large numbers, billions of cells square inch of the meat surface.
The single cells of the mold, although not visible without magnification, is much larger than the single bacterial cell, and any significant growth of molds on foods can be seen.
The visible mold comprises mycelia with or without spore heads.
The spore head carries the spore that will give rise to more growth.
Yeasts vary in size from that of the more common spherical bacteria to a form several times larger than this.
Like bacteria when grow in solution, the individual cells cannot be seen, but eventually, the cell numbers will accumulate to the point where the solution becomes cloudy. There are however, some instances on which groups of cells will, form visible (colonies) on foods or on the surface of solutions.
The Size of Microbes
