BacteriaBacteria

Smallest and simplest Smallest and simplest organisms on the planetorganisms on the planet

Also the most abundantAlso the most abundant 1 gram of soil has over 2.5 1 gram of soil has over 2.5

billion bacteriabillion bacteria

Shapes of BacteriaShapes of Bacteria

CoccusCoccus––sphericalspherical

BacilliBacilli – rod – rod SpirillaSpirilla-spiral-spiral

http://trc.ucdavis.edu/biosci10v/bis10v/week7/20f/http://trc.ucdavis.edu/biosci10v/bis10v/week7/20f/

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BacteriaBacteria

Prokaryotes – single celled, no Prokaryotes – single celled, no nucleus around their genetic nucleus around their genetic materialmaterial

Belong to either the Belong to either the Archaebacteria or Eubacteria Archaebacteria or Eubacteria kingdomskingdoms

Kingdom Kingdom ArchaebacteriaArchaebacteria Thrive in unusual placesThrive in unusual places

Salt lovers- Salt lovers- are found where are found where there is a high concentration of salt there is a high concentration of salt (the Dead Sea)(the Dead Sea)

Heat lovers Heat lovers – are found in hot – are found in hot springs (Yellow stone)springs (Yellow stone)

Methane makers- Methane makers- are found in are found in swampsswamps

Kingdom Kingdom EubacteriaEubacteria

Most bacteria are Most bacteria are eubacteriaeubacteria

Eubacteria has more Eubacteria has more individual organisms than individual organisms than any other kingdomany other kingdom

Eubacteria get food in 2 Eubacteria get food in 2 waysways

Most areMost are consumers consumers – – obtaining nutrients from obtaining nutrients from other organismsother organisms DecomposersDecomposers – feed on dead – feed on dead

organic matterorganic matter ParasitesParasites – feed on living – feed on living

organismsorganisms

Pseudomonas is one kind of bacteria found in the soil. Bacteria recycle dead plants and animals by turning them into minerals and nutrients that plants can use.

Eubacteria that aren’t Eubacteria that aren’t comsumerscomsumers

Some are Some are producersproducers – make – make their own foodtheir own food

Some are Some are photosyntheticphotosynthetic - - these bacteria have chlorophyll these bacteria have chlorophyll and convert sun energy into and convert sun energy into food like plantsfood like plants

Ex:Ex: CyanobacteriaCyanobacteria

CyanobacteriaCyanobacteria

Bacterial Bacterial producerproducer

Live in aquatic Live in aquatic environmentsenvironments

Bacteria Reproduction Bacteria Reproduction Binary Fission- simple cell Binary Fission- simple cell

divisiondivision1.1. Cell growsCell grows2.2. DNA replicates and attaches DNA replicates and attaches

to cell membraneto cell membrane3.3. DNA and copy separates as DNA and copy separates as

the cell grows even largerthe cell grows even larger4.4. Cell splits in Cell splits in 22. Each new cell . Each new cell

has a copy of the has a copy of the DNADNA

http://diverge.hunter.cuny.edu/~weigang/Images/06-11_binaryfission_1.jpghttp://diverge.hunter.cuny.edu/~weigang/Images/06-11_binaryfission_1.jpg

Most bacteria thrive and Most bacteria thrive and reproduce at optimal reproduce at optimal environments (the best)environments (the best)

Warm, moist environmentsWarm, moist environments If the conditions are If the conditions are

unfavorable, some species unfavorable, some species form a thick, protective form a thick, protective membrane membrane

Once the membrane is formed Once the membrane is formed the bacteria is known as an the bacteria is known as an endosporeendospore

Bacteria’s Role in the WorldBacteria’s Role in the World

Cleaning up- used to combat Cleaning up- used to combat pollutionpollution BioremediationBioremediation- use of bacteria - use of bacteria

and other microorganisms to and other microorganisms to change pollutants in harmless change pollutants in harmless chemicalschemicals

Clean up industrial, agriculture Clean up industrial, agriculture wastes and oil spillswastes and oil spills

Iron from acid Iron from acid run-off from run-off from mining can be mining can be treated on treated on site to reduce site to reduce and extract and extract pollutantspollutants

AntibioticsAntibiotics

Medicines used to kill bacteria Medicines used to kill bacteria and other microorganismsand other microorganisms

Some bacteria have been Some bacteria have been genetically engineered to genetically engineered to make large quantities of make large quantities of antibioticsantibiotics

FoodFood

Lactic-acid bacteria – convert Lactic-acid bacteria – convert sugar in milk to lactic acid sugar in milk to lactic acid which is a preservative and which is a preservative and adds flavoradds flavor

Used in sour dough bread, Used in sour dough bread, cheese, yogurt, sour cream, cheese, yogurt, sour cream, sourkraut and picklessourkraut and pickles

Harmful BacteriaHarmful Bacteria

Pathogenic bacteria – cause Pathogenic bacteria – cause diseasesdiseases ExamplesExamples Dental cavities, ulcers, strep Dental cavities, ulcers, strep

throat, food poisoning, bacterial throat, food poisoning, bacterial pneumonia, Lyme disease, pneumonia, Lyme disease, Tuberculosis, Typhoid feverTuberculosis, Typhoid fever