Yes, they do not abound in nature just to cause diseases or scare people with anthrax to be used for biological warfare or worse yet, with the SARS (Severe Acute Respiratory Syndrome) or AIDS virus, but believe it or not, microbes are used in food as well.
Microbes are very minute creatures that are capable of swarming and multiplying into thousands before our microscope-aided eyes. They can divide into two every 20 minutes under favorable conditions. They are so tiny, measuring a few millionths of a meter, that several billions could fit in a matchbox.
The three groups of microbes often associated with our food are bacteria, molds and yeasts. Bacteria can be round or spherical, single or in pairs, or they can live in clusters appearing like blue-violet grapes hanging on a vine. They can be curved like those causing cholera or rod-shaped, causing sliminess in some food.
When food turns black, gray, blue, yellow or reddish, and something cottony, fuzzy or thread-like grows on your bread, it is already unfit to eat. These spoilage-causing microbes are molds. They usually depend on plant and animal remains and some also infect living things. Molds can also appear velvety on the upper surface, some dry and powdery and others wet or gelatinous.
Bread rises and beer is brewed because of yeasts, microscopic fungi consisting of single spherical or oval cells. They are 10 times bigger than bacteria and they live on substances rich in sugar or starch.
Many of the food we eat are products of some microbial action. These types of food, whether universally accepted, like wine, bread and cheese or the more indigenous ones like tempeh in Indonesia or idli in India, are called fermented food. Fruit juices left to their resident microflora (microbes that normally thrive in fruits) acquire an alcoholic flavor; milk on standing becomes mildly acidic. Thus, we have wine and yogurt. Thanks to microbes, the food that we eat have unique and better taste, aroma and texture. – Biolife News Service