Reproduction of Microbes
Bacteria usually reproduce by fission, a transverse division across the cell to form two new cells.
Under favorable conditions, this form of reproduction continues until there are billions of cells per ounce (29.6 ml) of solution per square inch (6.5 cm2 ) of surface of food material.
It should be noted that microorganisms must live in liquid material and when they grow on food surfaces they are actually living in the liquid available on or in the food.
There are some instances in which sexual reproduction occurs in the bacteria, one cell uniting with another before division occurs, but this is not the usual circumstances.
Under favorable environmental condition, bacterial multiplication for some species occurs at an exceedingly rapid rate, a doubling of of the number requiring about 20 min.
From this standpoint, the number of cells with which a food is contaminated very important, for if the number is high, only a few hours may be required for bacterial multiplication to reach a level that will cause food spoilage.
Mold usually reproduce by means of spores, each organisms reproducing spores in a great numbers.
Mold spores are of two types; sexual spores produce by the fusion of two sex cells, or asexual spores that arise from the fertile hyphae.
Most molds produce asexual spores. Asexual spores are formed on the sides or ends of hyphae threads (a conidium) or produced in a special spore case called a sporangium.
Conidia contain many spores ,and when a spore comes in contact with as suitable growth medium under favorable condition, it growth to become the adult mold.
Yeasts reproduce by budding by fission or by spore formation. In budding a projection is formed on the original cell that eventually breaks off to form a new cell.
Some types may be undergo fission as do bacteria. One cell divides into two cells. Sometimes, yeasts reproduce by spore formation that may be sexual or asexual.
Reproduction of Microbes
