The document discusses the uses of microorganisms in the food industry. It begins by explaining that food can become contaminated from external sources and that most microbes play useful roles in food production. It then divides microorganisms into three main groups - bacteria, yeast, and molds. It explains that molds are generally only involved in food spoilage, while yeasts are widely used in fermentation due to their ability to produce ethanol and carbon dioxide. Bacteria also play an important role, being used to produce foods like cheese, yogurt, bread and more through fermentation. Fermentation allows foods to be preserved and develops new qualities while making the food inhospitable to pathogens. Certain molds are also needed to ripen

1. Uses of
Microorganisms in
Food
SUBHANANTHINI JEYAMURUGAN,
18PY17, M.SC., MICROBIOLOGY.
AYYANADAR JANAKI AMMAL COLLEGE SIVAKASI.

2. INTRODUCTION
Food may be contaminated from outside sources on the way from the
field to the processing plant, or during transport, storage and distribution.
There are thousands of different types of micro-organisms everywhere in air,
water, soil and foods, and in the digestive tract of animals and human.
Fortunately, the majority of microbes usefully functions in the
environment and in some branches of of food industry, such as production
of wine, beer, dairy products , bakery products, etc. On the other hand
unwanted food spoilage is generally caused by microbes and contamination
of food with pathogens causes food safety problems.

3. Groups of micro organisms
The micro-organisms occurring on and in foods are divided into three
groups:
 bacteria
yeast and
Molds.

4. uses
 Molds are generally concerned in the food spoilage; their use in the food industry is
limited.
 Yeasts are the most widely used microbes in the food industry due to their ability to
ferment sugars to ethanol and carbon-dioxide.
 Some types of yeast, like baker’s yeasts are grown industrially, and some may be used
as protein sources, mainly in animal feed.
 Bacteria are important in food microbiology may be divided into groups according to
the fermentation product, e.g. lactic acid bacteria, propionic acid bacteria, acetic acid
bacteria.
 Bearing in mind the food constituent attacked, prolytic, saccharolytic and lipolytic
bacteria may be distinguished.

5.  Microorganisms are essential for the production of foods such as cheese, yogurt,
bread, beer, wine and other fermented foods.
 Fermentation is one of the methods to preserve food and alter its quality.
 Yeast, especially Saccharomyces cerevisiae, is used to leaven bread, brew beer and
make wine.
 Certain bacteria, including lactic acid bacteria, are used to make yogurt, cheese, hot
sauce, pickles, fermented sausages and dishes.
 A common effect of these fermentations is that the food product is less hospitable to
other microorganisms, including pathogens and spoilage-causing microorganisms,
thus extending the food's shelf-life.
 Some cheese varieties also require molds to ripen and develop their characteristic
flavours.

6. Some micro organisms are
1. Bacteria
2. Yeast
3. Molds
4. Fungi
5. Citric acid production by fungi
6. Production of enzymes
7. Production of vinegar
8. Lactic Acid Bacteria
9. Lactic Acid Bacteria
10. Lactic Acid Bacteria

7. Thank you