Before we understand how bacteria affect your food we need to define what bacteria is, how it grows and exactly which bacteria is bad for your body.

What is bacteria?

Defining bacteria, Bacteria are Single-celled microorganisms that can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats.

They are about 0.5 to 2 micrometers in size. A grain of sand is 2 millimeters in size. This means you could fit 1000 bacterial cells into a single grain of sand.

Bacteria form what we call colonies which have millions of cells, which allows us to easily see bacteria on a medium that is grown in a lab, known as Agar plates.

There are 2 main types of bacteria defined as Gram-positive and Gram-Negative bacteria

All commonly occurring bacteria fall under these 2 categories.

Suffice to say, when we identify bacteria in the lab, there is a simple test that we use as a broad category to determine what bacteria we are looking at, this is known as a Gram stain.

This essentially means that there are 2 main types of bacteria that look and behave differently from each other.

What does bacteria need to grow and survive?

  • Temperature
  • Moisture Content
  • pH
  • Nutrient Content
  • Oxygen (some bacteria can grow without oxygen or very limited oxygen)
  • Time

Bacteria can survive at temperatures between 0 – 65 degrees C. Human associated bacteria grow at their best at 20 – 45 degrees C.
In food, bacteria love moisture-rich environments. For example, water residue in pots and plates or in food products that are moist with a high water content

Food is a perfect source of nutrients for bacteria to grow, and they will grow in most foods.

Bacteria grow best in food ranges from pH 3.0 – 7.5, however Bacteria can grow in various acidity levels, which is also what makes them so effective at surviving in the environment.

Bacteria can grow in both oxygen rich and poor environments.

In ideal conditions, Bacteria can rapidly multiply within 15 – 45 minutes

There are two different types of bacteria that were are concerned within food

  • Food spoilage bacteria
  • Food poisoning (Pathogenic) bacteria

Food Spoilage Bacteria

Easily detectable, as these make the food go off. We are able to see it, taste it and are more commonly able to smell it. This acts as a warning sign to say, do not eat this!

Pathogenic Bacteria

A small number of Pathogenic bacteria are able to make you extremely ill. These are the bacteria we are mostly concerned about, as you cannot see, taste or smell these bacteria.

Within this extensive category, there is a bacterium of each class, that were are generally concerned within the kitchen environment. This applies to both the home kitchen and a production kitchen (restaurant, hotel, food service).

E.coli (Gram-Negative) and Staphylococcus aureus (Gram-positive), is the most common food poisoning bacteria, but are also what is referred to as sanitary indicator organisms, as their presence in food indicates that something unsanitary or unhygienic as happened for them to be detected in the food. The food is thus potentially harmful and could make you sick by eating it.

Visit Food Consulting Services to learn more about Bacteria and how it could be harmful to your body. Food Consulting Services is a South African owned food testing laboratory that specializes in Microbiology, Chemistry, Physical testing, and Sensory tests.