Kingdom Bacteria - Weebly



Kingdom Bacteria

All are _____________ and the majority live as ________ (________) but some occur in _______. They reproduce mainly __________ by ______________ but can have a _______ reproductive stage (____________). Most bacteria are __________, but some bacteria can perform ______________ (___________).

Biological Importance of Bacteria

Advantages

1) Industry

Used in the production of cheese, vinegar, yogurt etc…

2) Agriculture

Used as natural pesticides or added to soils to enrich nitrogen content (nitrogen fixation – coversion of atmospheric nitrogen to nitrates)

3) Decomposers

Recycle organic material from dead organisms. Some bacteria are found in our intestines and aid in the digestion process.

4) Genetic Engineering

Scientists have used bacteria to study cell metabolism and molecular biology.

Engineered bacteria are used to produce useful substances like: insulin, antibiotics, hormones and anti-cancer drugs.

5) Fighting Disease

Some bacteria naturally produce substances (antibiotics), which inhibit the growth of harmful organisms (examples: streptomycin, erythromycin).

Bacteria on our skin compete with environmental bacteria and prevent them from affecting us.

6) Bioremediation

The process of using bacteria to destroy, transform or immobilized environmental contaminants.

For example, the bacterium Pseudomonas is used in the treatment of wastewater and sewage; a toxic wood preservative can be removed from soil by a bacterium from the genus Flavobacterium.

A relationship between two organisms (such as a bacteria and a human or plant or animal) is called a ___________________. In cases in which both partners benefit from the interaction it is referred to as _______________.

Disadvantages

1) Spoilage of Food

The action of bacterial decomposers can cause food to spoil and become harmful to eat. Examples: Clostridium botulinum (Botulism), Salmonella, E. coli

2) Disease

Many bacteria are _________. These bacteria can also be termed ________, meaning that one organism (the parasite) benefits at the expense of another organism (the host), which is often harmed but usually not killed.

These pathogenic (___________) micro-organisms typically produce deadly substances called ________. A toxin is a poison produced in the body of a living organism. It is not harmful to the organism itself but only to other organisms.

There are two types of toxins that bacteria produce, endotoxins and exotoxins.

|Endotoxins |Exotoxins |

|Released when certain bacteria split |Released by living, multiplying bacteria that travel throughout |

| |the host’s body |

|Seldom fatal |Often fatal, highly toxic |

|Cause fever, vomiting, diarrhea, rash |Various symptoms |

|Example: Salmonella |Example: Botulism |

Just one gram of the exotoxin that causes botulism could kill a million people!!!

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Classification of Bacteria

Bacteria can be classified using many different criteria. Some of these include:

1) Shape (three types):

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These shapes can be arranged (______________) in patterns or groupings:

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2) Metabolic Needs

Classification based on:

• Whether they are heterotrophs or autotrophs

• Do they need oxygen? (aerobic or anaerobic)

• Special food sources – carbon, nitrogen etc…

Examples:

|Term |Description |

| |Needs oxygen |

| |Die when exposed to oxygen |

| |Can grow with or without oxygen |

| |Use light as an energy source |

| |Use inorganic compounds as an energy source |

| |Feed on dead organisms or organic waste |

| |Grow in temperatures above 50oC |

| |Grow best in temperatures below 15oC |

| |Grow best at moderate temperatures |

|The Shapes of Bacteria |

Thousands of different types of bacteria are known and have been observed. Scientists can tell these organisms apart by the shape of the bacteria or by the way they join together. Write the meaning of the following terms.

1. bacillus ___________________________ 4. diplo _________________________

2. coccus ___________________________ 5. strepto _______________________

3. spirillum __________________________ 6. staphylo ______________________

Use the terms you defined above to name the bacteria in each diagram below. Write the name on the line below each diagram. Note: Some names will combine two of the terms. For instance, a chain (strepto) of round (coccus) bacteria is called a streptococcus.

__________________ ________________ __________________

__________________ ________________ __________________

__________________ ________________ ___________________

3) Colony Morphology

Describes the appearance of a colony in a Petri dish. Such as:

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4) Reaction with Gram Stain

• Gram + retain crystal violet stain (_____) - contain a ____________ layer in their ____________

• Gram - do not retain crystal violet stain (_____) - _____________ layer in their cell wall

5) Presence/Absence of:

Flagellum - used for _______________

Capsule - usually a __________ layer surrounding the cell used for __________

6) Spore Formation

Dormant form of many bacteria that is highly resistant to environmental conditions

Diagram of a Bacterium

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