1

BacteriaBacteria

Struture and Struture and Function…..Function…..

2

Prokaryotic & Prokaryotic & Eukaryotic CellsEukaryotic Cells

3

Earliest Earliest ProkaryotesProkaryotes• Most numerousMost numerous organisms on Earth

•Include all bacteriabacteria

• Earliest Earliest fossils datefossils date 2.5 billion years old

4

Kingdoms of Kingdoms of BacteriaBacteria

(review)(review)

Archaebacteria:Archaebacteria: Found in Found in harsh harsh environmentsenvironments

Undersea Undersea volcanic volcanic ventsvents, acidic , acidic hot hot springssprings, , saltysalty water water

5

ArchaebacteriaArchaebacteria

6

Kingdoms of Kingdoms of BacteriaBacteria

Eubacteria:Eubacteria: Called the Called the true true bacteriabacteria

Most bacteriaMost bacteria are in are in this groupthis group

Habitat = Habitat = warmwarm, , dampdamp So…..Cannot survive well So…..Cannot survive well in hot, cold, or dry in hot, cold, or dry habitats!habitats!

7

EubacteriaEubacteria

8

CharacteristCharacteristics of ics of BacteriaBacteria

9

Bacterial Bacterial StructureStructure

• Microscopic Microscopic prokaryotesprokaryotes

• No No nucleus or nucleus or membrane-bound membrane-bound organellesorganelles

• Contain Contain ribosomesribosomes• Single, circular Single, circular chromosome in chromosome in nucleoid nucleoid regionregion

10

Bacterial Cell

11

ProtectionProtection

•Cell Wall made of Cell Wall made of PeptidoglycanPeptidoglycan

•May have a sticky May have a sticky coating called the coating called the Capsule Capsule for for attachment to host attachment to host or other bacteriaor other bacteria

12

Sticky Bacterial Sticky Bacterial CapsuleCapsule

13

Bacterial Bacterial StructureStructure

•Have small rings Have small rings of DNA called of DNA called PlasmidsPlasmids

•UnicellularUnicellular

PLASMIDSPLASMIDS

14

15

Bacterial Bacterial StructureStructure

•Infoldings Infoldings of cell of cell membrane carry onmembrane carry on photosynthesis & photosynthesis & cellular cellular respirationrespiration

16

Bacterial Bacterial StructureStructure

•Most grow best at Most grow best at pH of 6.5 to 7.0pH of 6.5 to 7.0

•Many act as Many act as decomposersdecomposers recycling recycling nutrientsnutrients

•Some cause Some cause diseasedisease

17

Staphylococcus Staphylococcus BacterialBacterial

18

Useful BacteriaUseful Bacteria

• Some Some bacteria bacteria can can degrade degrade oiloil

• Used to Used to clean up clean up oil spillsoil spills

19

Useful BacteriaUseful Bacteria

•Other uses Other uses for for bacteria bacteria include include making making yogurt, yogurt, cheese, and cheese, and buttermilk.buttermilk.

20

FlagellaFlagella• Bacteria that Bacteria that are are motile motile have have appendages appendages called called flagellaflagella

• A bacteria can A bacteria can have have one or one or manymany flagella flagella

21

Monotrichous

Lophotrichous

Amphitrichous Peritrichous

22

PiliPili• Short proteinShort protein appendagesappendages

• SmallerSmaller than flagella than flagella• AdhereAdhere bacteria to bacteria to surfacessurfaces

• Used in Used in conjugationconjugation for Exchange of for Exchange of genetic informationgenetic information

23

Pili in Pili in ConjugationConjugation

24

Bacterial Bacterial ShapesShapes

25

Shapes Are Used Shapes Are Used to Classifyto Classify

• Bacillus: Bacillus: Rod shapedRod shaped

• Coccus: Coccus: Spherical Spherical (round)(round)

• Spirillum: Spirillum: Spiral Spiral shapeshape

26

27

Grouping of Grouping of BacteriaBacteria

•DiploDiplo- Groups of - Groups of twotwo

•StreptoStrepto- chains- chains•StaphyloStaphylo- - Grapelike Grapelike clustersclusters

28

29

30

DiplococcusDiplococcus

31

Streptococcus Causes Streptococcus Causes Strep ThroatStrep Throat

32

StaphylococcusStaphylococcus

33

Bacillus - Bacillus - E. E. colicoli

34

StreptobacilliStreptobacilli

35

SpirillumSpirillum

36

SpirochetesSpirochetes

37

LeptospiraLeptospira

38

39

Nutrition, Nutrition, Respiration, Respiration,

and and ReproductionReproduction

40

Modes of Modes of NutritionNutrition

• Saprobes Saprobes – feed on dead – feed on dead organic matterorganic matter

• ParasitesParasites – feed on a – feed on a host cellhost cell

• PhotoautotrophPhotoautotroph – use – use sunlight to make foodsunlight to make food

• ChemoautotrophChemoautotroph – – oxidize inorganic oxidize inorganic matter such as iron or matter such as iron or sulfur to make foodsulfur to make food

41

RespirationRespiration

• Obligate AerobesObligate Aerobes – – require Orequire O22 (tuberculosis (tuberculosis bacteria)bacteria)

• Obligate AnaerobesObligate Anaerobes – die – die if Oif O22 is present is present (tetanus)(tetanus)

• AnaerobesAnaerobes carry on carry on fermentationfermentation

42

1. Reproduction1. Reproduction

• Bacteria reproduce Bacteria reproduce asexually by binary fissionasexually by binary fission

• Single chromosome Single chromosome replicatesreplicates & then cell & then cell dividesdivides

• RapidRapid• All new cells All new cells identical identical (clones)(clones)

43

Cellular organism copies it’s genetic Cellular organism copies it’s genetic information then splits into two identical information then splits into two identical

daughter cellsdaughter cells

44

Binary Fission Binary Fission E. E. colicoli

45

2. Reproduction2. Reproduction

• Bacteria reproduce Bacteria reproduce sexually by Conjugationsexually by Conjugation

• Form aForm a tube between 2 tube between 2 bacteria bacteria to exchangeto exchange genetic materialgenetic material

• Held together byHeld together by pili pili• New cellsNew cells NOT identical NOT identical

46

ConjugationConjugation

47

3. Spore 3. Spore FormationFormation

• Form Form endosporeendospore whenever habitat whenever habitat conditions become conditions become harsh (little harsh (little food)food)

• Able to Able to survive survive for long periods for long periods of timeof time as as endospermendosperm

• Difficult to Difficult to destroy (heat destroy (heat resistant)resistant)

48

Biology I … STOP

•Biology ICan Stop Here!!

49

Transduction & Transduction & TransformationTransformation

• Genetically changeGenetically change bacteria bacteria• May become May become antibiotic antibiotic resistantresistant

• Transformed bacteriaTransformed bacteria pick up pick up pieces of DNA from dead pieces of DNA from dead bacterial cellsbacterial cells

• TransductionTransduction – viruses carry – viruses carry foreign DNA to bacteria; foreign DNA to bacteria; used to make insulinused to make insulin

50

Bacterial Bacterial KingdomsKingdoms

51

ArchaebacteriaArchaebacteria

• Archaebacteria can live in Archaebacteria can live in extremely harsh extremely harsh environmentsenvironments

• They They do not require oxygendo not require oxygen and can live in and can live in extremely extremely saltysalty environments as well environments as well as as extremely hotextremely hot environmentsenvironments

• Called the Called the Ancient Ancient bacteriabacteria

52

MethanogensMethanogens

• Live in Live in anaerobic anaerobic environments (no oxygen)environments (no oxygen)

• Get energy by Get energy by changing changing HH22 & CO & CO22 into methane gas into methane gas

• Found in Found in swampsswamps, , sewage sewage treatmenttreatment plants, plants, digestive tractsdigestive tracts of of animalsanimals

53

MethanogensMethanogens

• Break down Break down cellulose cellulose in a cow’sin a cow’s stomachstomach

• Produce Produce marsh marsh (methane) (methane) gasgas

54

Extreme Extreme HalophilesHalophiles

• Live in very Live in very salty watersalty water

• Use Use salt to salt to generate ATPgenerate ATP (energy)(energy)

• Dead Sea, Dead Sea, Great Salt Great Salt LakeLake inhabitantsinhabitants

55

Thermoacidophiles Thermoacidophiles or Thermophilesor Thermophiles

• Live in Live in extremely hot extremely hot environmentsenvironments

• Found in Found in volcanicvolcanic vents, hot vents, hot springs, springs, cracks on cracks on ocean floor ocean floor that leak acidthat leak acid

56

Kingdom Kingdom EubacteriaEubacteria

True BacteriaTrue Bacteria

57

CharacteristicsCharacteristics

• 3 basic shapes3 basic shapes (coccus, (coccus, bacillus, spirilla)bacillus, spirilla)

• Most are Most are heterotrophic heterotrophic (can’t make their own (can’t make their own food)food)

• May be May be aerobic or aerobic or anaerobicanaerobic

• Identified by Identified by Gram Gram stainingstaining

58

Gram StainingGram Staining

• Developed in Developed in 1884 by 1884 by Hans GramHans Gram

• Bacteria treated with Bacteria treated with purple Crystal Violet purple Crystal Violet & red Safranin stains& red Safranin stains

• Cell wallsCell walls either either stain purple or stain purple or reddish pinkreddish pink

59

Gram PositiveGram Positive• Have Have thick layer thick layer of peptidoglycanof peptidoglycan (protein-sugar (protein-sugar complex)complex)

• Single lipid Single lipid layerlayer

• Stain Stain purplepurple• Can be treated Can be treated with with antibioticsantibiotics

60

Gram Positive Gram Positive BacteriaBacteria

Lactobacilli Lactobacilli (makes yogurt & (makes yogurt & buttermilk)buttermilk)

Actinomycetes (Actinomycetes (make make antibiotics)antibiotics)

Clostridium Clostridium (lockjaw (lockjaw bacteria)bacteria)

Streptococcus Streptococcus (strep throat)(strep throat)Staphylococcus (Staphylococcus (staph staph infections)infections)

61

Gram Negative Gram Negative BacteriaBacteria

• Thin layer of peptidoglycanThin layer of peptidoglycan in cell wallin cell wall

• Extra Extra thick layer of lipidsthick layer of lipids• Stain Stain pink or reddishpink or reddish• Hard to treatHard to treat with with antibioticsantibiotics

• Some Some photosyntheticphotosynthetic but make but make sulfur not oxygensulfur not oxygen

• Some Some fix nitrogenfix nitrogen for plants for plants

62

Gram NegativeGram Negative

• Rhizobacteria Rhizobacteria grow in root grow in root nodules of nodules of legumeslegumes (soybeans, (soybeans, peanuts)peanuts)

• Fix NFix N22 from from air into air into usable usable ammoniaammonia

63

Gram NegativeGram Negative• Rickettsiae Rickettsiae are parasitic are parasitic bacteria bacteria carried by carried by ticksticks

• Cause Cause Lyme Lyme disease & disease & Rocky Mountain Rocky Mountain Spotted FeverSpotted Fever

64

CyanobacteriaCyanobacteria

• Gram Gram negativenegative• PhotosyntheticPhotosynthetic• Called Called blue-green blue-green bacteriabacteria

• Contain Contain phycocyaninphycocyanin (red-blue) pigments & (red-blue) pigments & chlorophyllchlorophyll

65

CyanobacteriaCyanobacteria• May be red, yellow, brown, May be red, yellow, brown, black, or blue-greenblack, or blue-green

• May grow in May grow in chainschains ((OscillatoriaOscillatoria))

• Have Have HeterocystsHeterocysts to help fix N to help fix N22

• First to re-enterFirst to re-enter devastated devastated areasareas

• Some cause Some cause EutrophicationEutrophication (use (use up O2 when die & decompose in up O2 when die & decompose in water)water)

66

CyanobacteriaCyanobacteria

67

SpirochetesSpirochetes• Gram Gram positivepositive• Flagella at each Flagella at each endend

• Move in Move in corkscrewcorkscrew motionmotion

• Some Some aerobicaerobic; ; others others anaerobicanaerobic

• May be May be free free living, parasitic, living, parasitic, or symbioticor symbiotic

68

Enteric BacteriaEnteric Bacteria

• Gram Gram negativenegative• Can live in Can live in aerobic & aerobic & anaerobicanaerobic habitats habitats

• Includes Includes E. coliE. coli in in intestinesintestines

• Salmonella Salmonella – – causes causes food poisoningfood poisoning

69

ChemoautotrophsChemoautotrophs

• Gram Gram negativenegative• Obtain energy from Obtain energy from minerals like ironminerals like iron

• Found in Found in freshwater pondsfreshwater ponds

70

Pathenogenic Pathenogenic BacteriaBacteria

71

PathogensPathogens

• Called Called germs or microbesgerms or microbes• Cause Cause diseasedisease• May produce May produce poisons or poisons or toxinstoxins

• EndotoxinsEndotoxins released after released after bacteria die (bacteria die (E. coliE. coli))

• Exotoxins Exotoxins released by released by Gram + bacteria (Gram + bacteria (C. C. tetanitetani))

72