1. Bacteria
Chapter 19-1

2. Microscopic organisms
Viruses = not living, but studied as micro-
Bacteria = divided into 2 kingdoms; most are helpful, harmful tracked by CDC & WHO
Protists = most diverse; show fungal, plant or animal characteristics
Fungus = decomposers; most are helpful, some are disease-causing

4. Prokaryote characteristics
Single-cell organisms
Anucleated (no nucleus)
Small (1-5 m)
Lacks organelles
Variety of shapes
Variety of growth patterns
Two kingdoms: Eubacteria and Archaebacteria

5. Bacterial characteristics:
Prokaryotic (no nuclear membrane)
Ribosomes only
Pili = for attachment
Capsule = outermost layer for extra protection
Unicellular (some colonial)
Varied metabolism & nutritional types
Often flagellated
May contain endospores… to survive harsh conditions
Binary fission to reproduce

7. Archaebacteria
Extremophiles: organisms that prefer extreme environments
Ex: salt marshes, deep sea ocean vents, swamps, etc.
aerobic halophil

8. Archaebacteria Lack the peptidoglycan of Eubacteria Have different
membrane lipids
DNA sequences
are more like
those of eukaryotes

9. Chemosynthetic bacteria
in deep sea vents
Photosynthetic Cyanobacteria
in fresh-water ponds or streams

11. Eubacteria cell structure
Cell wall
Cell membrane
Ribosome
Peptidoglycan
Pili
DNA
Flagella

12. See page 465

14. Practice

16. Bacterial shapes Bacillus = rod-shaped (ex: Lactobacillus)
Coccus = sphere (ex: Streptococcus)
Spirillum = coiled (ex: Spirochete)
Strepto (chains)
Staphylo (clusters)
(like grapes)
Diplo- (pairs)

17. Bacterial morphology
Coccus Bacillus Spirillum

19. Blue = causes
Lyme
disease Black = causes
syphilis

20. A Bacilli with and without flagella B Streptococci C Staphylococci D Diplococci E Spirochete F Club rod G Filamentous H Streptobacilli

21. Movement
Depending upon how the cells is flagellated, movements such as gliding or tumbling may occur.
flagellated E. coli

22. Gram stain
a technique that determines the differences in the composition of bacterial cell walls (thick or thin) which helps to determine which antibiotics to use.
Gram-positive bacteria thick peptidoglycan cell walls.
Gram-negative bacteria thinner cell walls with a outer lipid layer.

23. Gram negative Gram positive

24. How bacteria obtain nutrition
Heterotrophs: consume carbon matter to make ATP
Chemoheterotroph: consumes only
Photoheterotroph: consumes and photosynthesizes
Gram-negative, facultative anaerobic

25. How bacteria obtain nutrition
Autotrophs: produces carbon matter to make ATP
Photoautotroph: produces with light energy (photosynthesis)
Chemoautotroph: produces carbon matter without light source
Chemoautotroph: Purple sulfur bacteria

26. Nutritional diversity (Recap)
Autotrophs: (producers)
Photosynthetic = Cyanobacteria
Chemosynthetic = bacteria in deep ocean vents use sulfur instead of light for energy
Heterotrophs: (consumers)
Saprobes = decomposers feed on dead organic matter (nitrogen-fixing bacteria)
Parasitic = feed on living host (pathogenic)

27. Oxygen requirements
Obligate aerobe: requires constant oxygen supply in environment
Facultative aerobes: prefers oxygen, but not necessary
Facultative anaerobe: can survive with or without oxygen
Obligate anaerobe: requires constant lack of oxygen in environment

28. Binary fission asexual method of reproduction
parent cell splits into two daughter cells
Daughter cells are identical to parent cell

29. Binary fission Cell Replication (cloning) for prokaryotic cell
Much simpler than mitosis (like cytokinesis without the 4 other stages)

30. Conjugation Genetic material exchange
Increases genetic variation within bacterial population

31. Spore formation
In unfavorable growth conditions, structures (endospores) form to protect the bacterium.
Thick wall encloses the DNA and a small amount of cytoplasm.
The rest of the cell dies off.
The spore can survive in tough conditions for years.
Ex: Bacillus anthracis (anthrax) causes black necrotic lesions, sudden massive chest oedema followed by cardiovascular shock then death

32. Endospore formation

33. Methods of Microbe Transmission
3) Fomites:
(inanimate
objects)
1) Direct
Contact:
2) Air:

34. Early microbiologists
Louis Pasteur
Concluded that microorganisms cannot spontaneously generate
Showed world how heat kills microorganisms (pasteurization)

35. Microorganisms & You
Food for heterotrophs typically are carbon-based macromolecules:
Carbohydrates, lipids, & proteins
Bacteria & fungus are responsible for food spoilage because many are saprobes

36. Helpful bacteria Decomposers Nitrogen fixers: Rhizobium
Symbiosis with humans in large intestines
Food production
Rhizobium

37. Food & Microorganisms: Making cheese
Bacteria placed in an anaerobic environment, and the milk breaks down to form cheese
Milk (sugar source) + little oxygen → lactic acid + protein solids + curds
“Little Miss Muffet, sat on her tuffet, eating her… cottage cheese”

38. Yogurt:
Yogurt is produced by a mixed culture of 2 types of bacteria. Imbedded in particles of the protein casein, you will see chains of cocci or diplococci (Streptococcus thermophilus) and big rod-shaped bacilli (either Lactobacillus acidophilus or L. bulgaricus).
Buttermilk:
Buttermilk is the fermentation of milk by a culture of lactctic-acid producing Streptococcus lactis plus Leuconostoc citrovorum which converts lactic acid to aldehydes and ketones which gives buttermilk its flavor and aroma.

39. Making cured meats Some bacteria are able to ferment meat products
The final products are sausages, bologna, salami, country cured hams, etc

40. Making pickled vegetables
Sauerkraut is a product of lactic acid fermentation of Lactobacillus genus bacteria.
Bacteria ferments the cabbage, but salt is added to prevent other bacteria from spoiling the product.

41. Some cured food products
Cured animal products:
Beef
Corned beef
Bresaola
Tapa
Pork
Ham
Prosciutto
Jambon de Bayonne
Jamón serrano
Jinhua ham
Coppa
Lomo
Capicola
Lardon
Bacon and Pancetta
Elenski but
Sausage
Salami
Pepperoni
Chorizo
Linguiça
Fish
Anchovy
Salt cod
Lox (salmon)
Pickled herring
Cured vegetable products:
Tofu
Sauerkraut
Kimchi
Pickled cucumbers
Olive (fruit)

42. Nitrogen cycle includes nitrogen fixation

43. How else are bacteria helpful?
Nitrogen-fixation
decomposing bacteria convert atmospheric N2 for use by autotrophs

44. Symbiotic bacteria allow a host to live a different lifestyle than would normally be possible

45. Cyanobacteria (& unicellular algae) produce most of the world’s oxygen by photosynthesis

46. Microorganisms & your health
Antibiotics that kill pathogenic
microorganisms are made
from microorganisms