Microbiology – Alcamo Growth and Growth Phases

1. Microbiology – AlcamoGrowth and Growth Phases

2. Growth • Human Terms: Growth = __________ • Microorganism Terms: Growth = __________

3. Growth • Binary Fission – bacteria reproduce __________ : • Chromosome __________ • Cell __________ • Plasma membrane __________ in at center • __________ __________ distributes evenly • Cell wall thickens to separate dividing cells

4. Growth • Binary fission – gives __________ to bacteria • The first bacterium ________ _______ • It __________ and becomes a new, young cell again • The original __________ (billions of years old) is still among us

5. Growth Reproduction: __________ __________ 20 Generation 21 Generation 22 Generation 23 Generation

6. Generation Time • Time between _______ __________ when bacteria grows and develops its unique features • Also called “________ _________” • A determining factor in the __________ of time that passes between entry of an organism into our bodies and the __________ of disease symptoms

7. Growth • Each microorganism has it’s own characteristic __________ __________ • Range: • Usually 1 to 3 __________ • __________ 20 minutes (E. coli) • __________ 33 hours (T. pallidum- syphilis)

8. BACTERIAL GROWTH IS LOGARITHMIC

9. Growth Growth Rates • If after 48 hours of __________, a colony is pinpoint size, __________ GT is indicated. • If after 48 hours, the __________ is ¼” wide, __________ GT is indicated.

10. Growth Example E. coli has a 20 minute __________ __________ under ideal conditions:

11. Growth Growth Rates • Exponential growth signifies ideal __________ and maximum __________ • But the __________ __________ of bacteria is never fully realized due to environmental __________

12. Growth Phases • Many dynamics __________ the population of bacteria over the course of __________ • A certain population’s history may begin when: • Several bacteria enter the __________ __________ tract • Several bacteria are transferred to a tube of __________ __________ in a lab

14. Growth Phases Lag Phase: • First few hours of __________ __________ • Period of __________ to new environment • If an __________, WBC’s can be __________ some cells • If in a lab, some cells may die from __________ __________

15. Growth Phases • The activity of the remaining cells is intense as they: • Store __________ • Synthesize __________ • Prepare for __________ __________ • But the curve remains at a __________, where the number of cells reproducing __________ the number of cells dying

16. Growth Phases Log Phase: • Also called “__________” phase • The mass of each cell increases __________ and __________ follows • As each generation time passes, the number of bacteria __________ and the graph rises __________

17. Growth Phases • In humans, disease symptoms arise during the __________ __________ • Bacterial population is high enough to __________ __________ • Fever, __________, tissue damage arise • In a lab, visible signs of growth will be seen: • colonies will appear on ________ ________ • broth media will become __________

18. Growth Phases • Research experiments are usually done during the __________ __________ because the population of bacteria is at its __________ __________

19. Growth Phases Stationary Phase: • Period of __________ __________ numbers • Reproduction rate = __________ __________ • No change in total number of __________

20. Growth Phases • Stationary Phase: • In humans: • the __________ __________ may be destroying the bacteria • antibiotics have been __________ • In the lab: • nutrients are becoming __________ • __________ __________ are building up • oxygen or water could be in __________ __________

21. Growth Phases Decline Phase: • Environment becomes progressively __________ and exerts its __________ __________ • pH is changing • oxygen and nutrients are __________ • accumulation of __________

22. Growth Phases • Decline Phase: • Number of cells __________ __________ the number of new cells formed • Spore forming species will start to produce __________ • Flagellated species will try to __________ to a new location • For other species, culture death is __________

23. Things That Affect GrowthTemperature • Different species grow at different temperatures • __________ – grow best between 0oC and 20oC • __________ – grow best between 20oC and 40oC • __________ – grow best between 40oC and 90oC

24. Things That Affect Growth Temperature • Most bacteria are __________, especially __________ __________ that grow in the human body (37oC) • When the body’s temperature rises to 40oC (104oF) there is a slightly _________ affect on bacterial ________ • The lab incubator is set at 37oC to __________ bacterial growth

25. Things That Affect Growth Temperature • Some __________ can grow at refrigerator temperatures and cause __________ __________ • Staphylococci can grow in the refrigerator and deposit their __________ on cold cuts, salads and leftovers • If these foods are eaten without further cooking, __________ __________ can result

26. Things That Affect Growth Temperature • __________ outbreak in a restaurant in 1991 • Restaurant employee prepared Caesar salad dressing which contains raw egg • It may have remained at room __________ too long before being served • Within 3 days, 15 people were __________ with diarrhea, fever, cramps and __________

27. Things That Affect Growth Oxygen • __________ bacteria – require __________ to grow • __________ bacteria – require an oxygen-free environment to grow • Includes __________ species that cause tetanus and botulism • __________ bacteria – grow in either the presence or __________ of oxygen • includes many staphylococci, streptococci and bacilli

28. Things That Affect Growth pH • Bacteria have a __________ internal environment • Will tolerate a pH range of __________ • Human blood and tissues have a pH of __________ • Provides a __________ environment for disease causing bacteria to __________

29. Things That Affect Growth pH • Certain bacteria are __________ __________ • Useful in the food and dairy __________ • Lactobacillus and Streptococcus produce the acid that converts: • milk to __________ • __________ to sour cream • milk curds to __________ • These bacteria __________ __________ __________ to good health even when eaten in large quantities

30. Things That Affect Growth pH • Most bacteria do not grow well under __________ __________ • Stomach’s __________ __________ prevents disease • Certain __________ __________ are hardly ever contaminated with bacteria • Citrus fruits • __________ • Tomatoes

31. Things That Affect Growth Pattern of Nutrition • Bacteria (like us) need: • __________ • __________ to serve as energy sources and as raw materials for synthesis of cell __________

32. Things That Affect Growth Pattern of Nutrition • Two patterns for obtaining nutrition: • __________ – can make their __________ food using inorganic carbon, water and sun’s energy • __________ – obtain preformed organic molecules from the __________ for structural components and energy • __________ – feed exclusively on dead organic matter such as rotting wood • __________– feed on living organic matter such as human tissues

33. Things That Affect Growth Bacterial Cultivation • In the lab, bacteria are grown in: • __________ __________ containing water, beef extract and peptone (protein supplement) • __________ __________ – contains the same, plus agar, a polysaccharide derived from marine algae *Most bacteria __________ __________ in these

34. Things That Affect Growth Bacterial Cultivation • Some bacteria require __________ or __________ media • The streptococci that cause strep throat and scarlet fever grow well when __________ __________ is added to the media • __________ __________– heated before solidification to disrupt the red blood cells and release __________ • Sometimes called __________ __________

35. Things That Affect Growth Bacterial Cultivation • __________ __________– contain ingredients to __________ the growth of certain bacteria in a mixture while __________ the growth of others • __________ salt agar – high salt content __________ the growth of most bacteria, but allows for staphylococci to grow • __________ methylene blue agar – contain dyes that __________ Gram-positive bacteria, but __________ growth of Gram-negative

36. Things That Affect Growth Bacterial Cultivation • __________ __________– makes it easy to distinguish colonies of one organism from __________ of another on the same plate • MacConkey’s agar contains __________ __________ as well as lactose • Colonies of bacteria that __________ __________ are red • Colonies of bacteria that __________ ferment lactose are colorless

37. Things That Affect Growth Bacterial Cultivation • __________ __________– not chemically defined • Exact components and quantities are not known • Some bacteria will only grow on natural media • __________ __________ - chemically defined • The nature and amount of each component is known

38. Things That Affect Growth Intermicrobial Relationships • __________ – situation in which two populations of organisms interact in a __________ and __________ association • Benefits obtained may involve: • food • __________ • support

39. Things That Affect Growth Intermicrobial Relationships • __________ – symbiosis that benefits both populations • Bacteria living on roots of plants: • Bacteria trap __________ for plants to synthesize __________ __________ • Plants provide a __________ environment and __________ __________ for bacteria

40. Things That Affect Growth Intermicrobial Relationships • __________ – one population receives benefit from the relationship while the other is not __________ or __________ • Bacteria that inhabit human skin: • __________ has a place to live and food • We are not helped or __________ in any way

41. Things That Affect Growth Intermicrobial Relationships • __________ – two populations live together and accomplish what neither could alone • __________ __________ – two populations of bacteria (usually rods and spirochetes) must be present for __________ of the __________ __________ to occur

42. Things That Affect Growth Intermicrobial Relationships • __________– symbiosis is beneficial to one population (__________) but harmful to the other (__________) • The bacteria of all human diseases are __________

43. Applications • Industrial: __________ __________ products Penicillin  Vinegar  Wine Pickles  Beer Cheese  Alcohol • Medical: Phases of disease parallel __________ __________ of pathogen