ENVIRONMENTAL INFLUENCES

microorganism that thrives in high salt concentrations

halophile

can microbes regulate their internal temperature?

no

what happens to enzymes below optimum temperature

not catalytic

what happens to enzymes above optimum temperature

denaturation

psychrophiles

0-20

psychrotrophs

0-35

mesophiles

20-45

thermophiles

45-85

hyperthermophiles

85-100

obligate aerobe

needs air exposure

obligate anaerobe

oxygen exposure kills them

microaerophiles

uses oxygen but atmospheric oxygen kills them

facultative anaerobe

can grow with/without oxygen but prefers to grow with oxygen to USE it

aerotolerant anaerobe

can grow with/without oxygen but DOESNT USE oxygen

oxic zone

high levels of dissolved oxygen

anoxic zone

no free dissolved oxygen

at what pressure do land and water surface microbes live?

1 atm

barophilic

requires high pressure for growth

converts superoxide radicals into hydrogen peroxide; first line of defense adainst ROS

superoxide dismutase (SOD)

breaks hydrogen peroxide into water and O2; common in aerobes and facultative anaerobes

catalase

reduces hydrogen peroxide to water using electron donors; allows survival in low-oxygen/fluctuating envrionments

peroxidase

why cant anaerobes eliminate toxic oxygen radicals

they lack the enzymes required for it

surviving salt

halomonas elongata

tolerating salt

staphylococcus aureus

surviving cold

psychromonas ingrahamii

surviving heat

thermus aquaticus

surviving atmospheric pressure

photobacterium profundum