Lab 4 ppt

temperature is important in controlling the _______ of microorganisms

growth

cardinal temps

bacterias maximum, minimum, and optimum temps

minimum temp

lowest temp for growth to occur

maximum temp

highest temp for growth to occur, limit of reproduction

optimum temp

fastest growth rate. enzyme efficiency and reproduction at max

psychrophiles

grow from -5C to 20C

mesophiles

grow from 20C to 45C

mesophiles contain many ______

pathogens

psychrotrophs

catergory of mesophiles that grow at 0C

psychrotrophs cause _______ ________

food spoilage

thermophiles

grow from 45C to 60C

thermophiles can be ___________ or ____________

facultative or obligate

extreme thermophiles

live in very hot conditions

thermotolerant pathogens

campylobacter jejuni, clostridium perfringes, aspergillus fumigaths

campylobacter jejuni optimally grow around

42C

campylobacter jejuni are associated with _________

poultry

clostridium perfringes optimally frow at

45C

clostridium perfringes are a common cause of ______ ______

food poisening

aspergillus fumigaths optimally grow at

50C

aspergillus fumigaths are _______ pathogens

fungal

there are no ___________ pathogens

psychrophillic

psychrotolerant pathogens

listeria monocytogens, yersinia enterolitica, clostridium botulism, some aeromonas species

listeria monocytogens can multiply at ______ temps

refrigerator

what species did we use in temp experiment?

e coli, g stearothermophilus, p fluorescens, s. marcescens

E. coli and S. marcescens are both...

mesophiles

g. stearothermophilus is a ...

thermophile

g. stearothermophilus optimally grows at ____

60C

p. fluoresces is a ...

psychrotroph

p.fluroescens grow between...

25-30C

S. marescens produces ____________ at room temp 24C

prodigiosin

S. marcescens becomes more ________ towards the higher end of its optimal growth range

pink

what happens to a cells enzymes and proteins when temp is too low

molecular activity decreases, protein synthesis slows, rxn time decreases. causes no growth to occur

what happens to a cells enzymes and proteins when temp is too high

denatures and disrupts protein and enzymes. causes no growth to occur

pure water ionizes to a very small extent into...

hydrogen ions (H+) and hydroxide ions (OH-)

acids

molecules that release hydrogen ions in solution

_______ acids release more H+ than _______ acids

strong, weak

bases

lower H+ conc

sme bases release ____

OH-

some bases bind ________

H+

pH of a solution can affect...

shapes and functions of molecules, rates of chemical reactions, ability of two molecules to bind each other, ability of ions or molecules to dissolve in water

acidophiles

grow well in environments below 5.5 pH

neutrophiles

prefer between 5.5-8.5 ph

alkaphiles

organisms that live around 8.5 pH

media used in pH experiment

pH adjusted tryptic soy broth

organisms used in pH experiment

a. faecalis, l. acidophilus, l. lactis, s. saprophyticus

pH pivot points

5 and 9

Alcaligenes faecalis, Lactococcus lactis, Staphylococcus saprophyticus are all...

neutrophiles

A. faecalis grows optimally at pH __

7

L. lactis and S. saprophyticus grow optimally at pH ___

6.5

Lactobacillus acidophilus is an _________

acidophile

Lactobacillus acidophilus grows optimally at pH _

5

osmotic pressure

quantifies a solutions ability to pull water through a semipermeable membrane

hyposmotic solution

water moves into cell until internal hydrostatic pressure balances osmotic pressure

hyperosmotic solution

water flows out of cell

isosmotic

water moves in both directions equally, resulting in no net movement

most bacteria and archaea thrive within a specific ______ range

salinity

halophiles

bacteria that optimally grow in NaCl concentrations of 3% or more

extreme halophiles require ________ salt due to specialized membranes and enzymes

15-25%

osmotolerant species

grow over a wide range of salinities

facultative halophiles

can tolerate high salt up to a certain amount

example of a facultative halophile

Staphylococcus

organisms used in osmotic pressure experiment

e. coli, h. salinarum, s. epidermidis

plasmolysis

cell in a hyperosmotic solution, water moves out and membrane seperates from cell

cell lysis

cell in a hyposmotic solution, water moves in and causes cell to burst

osmosis

net diffusion of water

E coli thrive at... (like most microbes)

low salinities, less than 3%

example of a halotolerant organism

Staphylococcus aureus

Staphylococcus aureus can grow in presence of salt up to ______%

7.5

which organisms is an extreme halophile

halobacterium salinarum

halobacterium salinarum is in domain __________

archaea