Heal Yourself At Home


Introduction to bacteria

Bacteria are:

✔ Single-celled organisms found in all types of environments

✔ Can only be seen through a microscope measured in micrometer (one millionth of a meter)

✔ Prokaryotes they do not contain a nucleus

✔ Grouped in families – having the same bacterial ancestors.

E.g. Enterobacteriaceae

✔ A family member is a genus – each genus having developed its own peculiar characteristics. E.g. Escherichia

✔  A genus has different species E.g Escherichia Coli (E. Coli)

✔ Different shapes, sizes and many other characteristics

Bacterial Purpose / Activities

Harmless, beneficial or harmful (pathogenic) bacteria?

–    Harmless – do not affect humans

–    Beneficial Bacteria - produce enzymes that:

✔ Aid food digestion and production of some vitamins - break down complex food molecules into simpler materials (especially in ruminants); Responsible for production of vitamin K and some b vitamins

✔ Are Involved in production of many foods eaten by humans milk souring bacteria are used to produce yogurt, cottage cheese, and buttermilk; other bacteria used to produce vinegar and sauerkraut

✔ Are the principal agents of putrefaction - the anaerobic decomposition of organic materials, especially protein (i.e. contains nitrogen); produces foul odors

✔ Are the principal agents of decay - the gradual decomposition of organic matter exposed to air by bacteria and fungi.

–    Pathogenic bacteria – cause disease by different mechanisms:

✔ Directly attack tissues (in other life-forms) E.g.Bacterial Leaf Spot caused by Pseudomonas cichorii

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