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BacteriaBacteria

Domain: Bacteria and ArchaeaDomain: Bacteria and Archaea

Kingdom Eubacteria and Kingdom Eubacteria and Archaebacteria (previously Archaebacteria (previously

Monera)Monera)

Crash Course: Bacteria Video

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CharacteristicsCharacteristics

Lack nucleus and organelles (prokaryotic)Lack nucleus and organelles (prokaryotic)Usually smaller than eukaryotic cellsUsually smaller than eukaryotic cellsSingle cells but can form strands or Single cells but can form strands or

clumpsclumpsSingle circular piece of DNASingle circular piece of DNAReproduce by binary fissionReproduce by binary fission

Can divide every 20 minutesCan divide every 20 minutesLimited food source reduces actual rate of Limited food source reduces actual rate of

divisiondivision

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CharacteristicsCharacteristics

Flagella that spins for movementFlagella that spins for movementSome have piliSome have pili

Shorter and thicker than flagellaShorter and thicker than flagellaUsed for attachmentUsed for attachment

www.ou.edu/class/pheidole/bacteria.html

Aerobic or anaerobic metabolismAerobic or anaerobic metabolism

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Classification of Bacteria Classification of Bacteria

Ways Bacteria are classifiedWays Bacteria are classifiedShape – most common way to classifyShape – most common way to classifyArrangement (Number/ size)Arrangement (Number/ size)Food requirementsFood requirementsOxygen requirementsOxygen requirementsHow they move/number of flagellaHow they move/number of flagellaCell wall composition (gram staining)Cell wall composition (gram staining)Method of reproduction – rarely usedMethod of reproduction – rarely used

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Bacterial ShapesBacterial Shapes

Bacillus = rodBacillus = rod

Coccus = roundCoccus = round

Spirillum = spiralSpirillum = spiral

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Bacterial ArrangementBacterial Arrangement Diplococcus = 2 round Diplococcus = 2 round

bacteria cellsbacteria cells

Streptococcus = chains of Streptococcus = chains of round bacteriaround bacteria

Staphylococcus = cluster Staphylococcus = cluster of round bacteriaof round bacteria

Tetrad = 4 round bacteria Tetrad = 4 round bacteria in a squarein a square

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Bacterial ArrangementBacterial Arrangement

Diplobacillus = pairs Diplobacillus = pairs of rod shaped of rod shaped bacteriabacteria

Streptobacillus = Streptobacillus = chains of rod shaped chains of rod shaped bacteriabacteria

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Bacteria FactsBacteria Facts

Bacteria is everywhereBacteria is everywhereThe number of bacteria in the human The number of bacteria in the human

mouth is greater than the number of mouth is greater than the number of people who ever lived on the earth.people who ever lived on the earth.

Bacteriologist is a scientist who studies Bacteriologist is a scientist who studies bacteria.bacteria.

Bacteria is grown in a lab as a culture with Bacteria is grown in a lab as a culture with nutrient agar (food source).nutrient agar (food source).

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Gram StainingGram Staining

Used to identify the type of bacteria Used to identify the type of bacteria presentpresent

Used to determine the best antibiotic Used to determine the best antibiotic needed to kill the bacterianeeded to kill the bacteria

Antibiotic = interferes with the life Antibiotic = interferes with the life processes of bacteriaprocesses of bacteriaAlexander Fleming – penicillin inventorAlexander Fleming – penicillin inventor

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Why are bacteria so resistant?Why are bacteria so resistant?

Endospores = thick walls around bacteria Endospores = thick walls around bacteria during harsh conditionsduring harsh conditionsEx- low nutrients, drought, high temperatures, Ex- low nutrients, drought, high temperatures,

low temperature, etc.low temperature, etc.Endospores will open up when conditions Endospores will open up when conditions

become more favorable.become more favorable.

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Bacteria Structure Bacteria Structure

Draw a bacterial cell. Label cytoplasm, DNA, Draw a bacterial cell. Label cytoplasm, DNA, ribosomes, flagella, pili, capsule, cell wall, cell ribosomes, flagella, pili, capsule, cell wall, cell membranemembrane

Capsule = purple outer layer

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Obtaining Energy (nutrition)Obtaining Energy (nutrition)

1.1. Photosynthetic = makes own foodPhotosynthetic = makes own food

2.2. Heterotrophs = obtain food from another Heterotrophs = obtain food from another sourcesource

a.a. Saprophytes = Eat dead organismsSaprophytes = Eat dead organisms

b.b. Symbiotic relationships = live in close association Symbiotic relationships = live in close association with another organism with another organism

Mutualism = both organisms are helpedMutualism = both organisms are helped Example= sheep & cows have bacteria in stomach to aid in Example= sheep & cows have bacteria in stomach to aid in

grass digestiongrass digestion Parasitism = one is helped; other is harmedParasitism = one is helped; other is harmed

Host = organism that is harmedHost = organism that is harmed

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Obtaining energy (nutrition)Obtaining energy (nutrition)

3.3. ChemoautotrophsChemoautotrophs Use inorganic compounds such as ammonia Use inorganic compounds such as ammonia

and hydrogen sulfide to make foodand hydrogen sulfide to make food Use organic compounds such as methane to Use organic compounds such as methane to

make food make food

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RespirationRespiration

Obligate aerobes - require oxygenObligate aerobes - require oxygenObligate anaerobes – require no oxygen; Obligate anaerobes – require no oxygen;

oxygen will poison the bacteria and kill itoxygen will poison the bacteria and kill itBotulism – produces toxins in improperly Botulism – produces toxins in improperly

canned foodscanned foodsFacultative anaerobes – can function with Facultative anaerobes – can function with

or without oxygen but will not be poisoned or without oxygen but will not be poisoned by the presence of oxygenby the presence of oxygen

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Economic ImportanceEconomic Importance

Pathogenic – disease causingPathogenic – disease causingExamples: tuberculosis, anthrax, bubonic Examples: tuberculosis, anthrax, bubonic

plague, cholera, dental cavities, lyme disease, plague, cholera, dental cavities, lyme disease, typhus, strep throat, acne, tetanus, stomach typhus, strep throat, acne, tetanus, stomach ulcersulcers

Food PoisoningFood PoisoningBotulismBotulismE. coli (ground beef)E. coli (ground beef)

Food spoilageFood spoilage

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Economic ImportanceEconomic Importance

BiowarfareBiowarfareFood ProductionFood Production

Pickles, buttermilk, cheese, sauerkraut, Pickles, buttermilk, cheese, sauerkraut, olives, vinegar, sourdough bread, sausageolives, vinegar, sourdough bread, sausage

Make chemicalsMake chemicalsAcetone, butane, medicinesAcetone, butane, medicines

MiningMiningExtracts minerals from impure sourcesExtracts minerals from impure sources

Clean up petroleum and chemical spillsClean up petroleum and chemical spills

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Preventing Food SpoilagePreventing Food Spoilage

RefrigerationRefrigerationFreezingFreezingDryingDryingSaltingSaltingCanningCanningHeating thoroughlyHeating thoroughly