1. Bacterial Cell Structure
Fig. 4.1

2. Cytoplasm dense gelatinous solution of sugars, amino acids, & salts
70-80% water
serves as solvent for materials used in all cell functions

3. Chromosome
single, circular, double-stranded DNA molecule that contains all the genetic information required by a cell
DNA is tightly coiled around a protein, aggregated in a dense area called the nucleoid

4. DNA temperature melting Bacteria classification
G + C

5. plasmids small circular, double-stranded DNA
free or integrated into the chromosome
duplicated and passed on to offspring
not essential to bacterial growth & metabolism
may encode antibiotic resistance, tolerance to toxic metals, enzymes & toxins
used in genetic engineering- readily manipulated & transferred from cell to cell

6. Ribosomes made of 60% ribosomal RNA & 40% protein
consist of 2 subunits: large & small
procaryotic differ from eucaryotic ribosomes in size & number of proteins
site of protein synthesis
All cells have ribosomes.

8. Inclusions, granules intracellular storage bodies
vary in size, number & content
bacterial cell can use them when environmental sources are depleted
Examples: glycogen, poly-b-hydroxybutyrate, gas vesicles for floating, sulfur and polyphosphate granules

10. Fig 4.10

11. Cytoplasmic membrane
Protoplast
Spheroplast
L forms

12. 4 groups based on cell wall composition
Gram positive cells
Gram negative cells
Bacteria without cell walls
Bacteria with chemically unique cell walls

13. Gram positive
Gram negative

14. Gram positive Gram negative
Fig 4.16

15. Lipopolysaccharide O-antigen Highly variable n Core Heptoses
Ketodeoxyoctonic acid
Lipid A
Glucosamine disaccharide
Beta hydroxy fatty acids
(Hydroxy myritic Acid)

16. LPS function Endotoxins Exotoxins

17. Gram positive wall

18. Gram negative cell wall

19. Peptidoglycan

20. Cytoplasm Cytoplasm Periplasmic space Lipoteichoic acid
Peptidoglycan-teichoic acid
Cytoplasmic membrane
Cytoplasm
Lipopolysaccharide
Porin
Outer Membrane
lipoprotein
Periplasmic space
Inner (cytoplasmic) membrane
Cytoplasm

21. Gram Positive Cell Envelope
Lipoteichoic
acid
Peptidoglycan-teichoic acid r r r
Cytoplasmic membrane
Cytoplasm

22. Glycocalyx
Coating of molecules external to the cell wall, made of sugars and/or proteins
2 types
capsule - highly organized, tightly attached
slime layer - loosely organized and attached
Functions
attachment
inhibits killing by white blood cells
Receptor (K antigen)

23. 2 Types of Glycocalyx

24. Biofilms

25. Flagella

26. lophotrichous
Monotrichous
amphitrichous
peritrichous

27. Fig 4.2b

28. Fimbrae
Adhesion to other cells and surfaces

29. pili rigid tubular structure made of pilin protein
found only in Gram negative cells
Functions
joins bacterial cells for DNA transfer (conjugation)
adhesion

30. Conjugation

31. endospores

32. Important components in endospore: Calcium Dipicolinic Acid

33. Sporulation

34. The endospore

36. Major Taxonomic Groups of Bacteria
Gracilicutes – gram-negative cell walls, thin-skinned
Firmicutes – gram-positive cell walls, thick skinned
Tenericutes – lack a cell wall & are soft
Mendosicutes – archaea, primitive procaryotes with unusual cell walls & nutritional habits

37. Grwth in Bacteria
Temperature
Nutrients pH
Osmotic pressure

38. Temperature
Minimum temperature – lowest temperature that permits a microbe’s growth and metabolism
Maximum temperature – highest temperature that permits a microbe’s growth and metabolism
Optimum temperature – promotes the fastest rate of growth and metabolism

39. 3 temperature adaptation groups

40. Bacterial Metabolism Phototroph Chemotroph
Photoautotroph (Photolitotroph)
Photoheterotroph (Photoorganotroph)
Chemotroph
Chemoautotroph (Chemolitotroph
Chemoheterotroph (Chemoorganotroph)

41. Stages of metabolism in chemoheterotrophic bacteria
Digestion
Absorption (Passive and active transportation)
Preparation for oxidation
Oxidation

42. Oxygen requirements

44. Fermentation
Incomplete oxidation of glucose or other carbohydrates in the absence of oxygen
Uses organic compounds as terminal electron acceptors
Yields a small amount of ATP
Production of ethyl alcohol by yeasts acting on glucose
Formation of acid, gas & other products by the action of various bacteria on pyruvic acid

45. Fermentation

46. Binary division

47. Growth Curve

48. Continuous Culture, Chemostat
Chemostats are a means of keeping a culture in log phase indefinitely.
Continuous Culture, Chemostat

49. Methods in bacterial identification
Microscopic morphology
Macroscopic morphology – colony appearance
Physiological / biochemical characteristics
Chemical analysis
Serological analysis
Genetic & molecular analysis
G + C base composition
DNA analysis using genetic probes
Nucleic acid sequencing & rRNA analysis

50. Bacterial Colonies Standard Bacterial Count Colony-Forming Units
Plaque-Forming Units
Spread Plate
Pour Plate
Soft-Agar Overlay

51. Solid Medium