review for exam 1 (MCB 100)

vegetative cell

normal, growing bacterial cell

red stained with safranin

vegetative cell

malachite green

endospores

endospores

survival mode during starvation/harsh conditions, dormant (alive, but inactive)

gram positive bacterias like clostridium and bacillius

what happens stationary phase

nutrients become depleted, smaller, needing less nutrients, express stress proteins to protect DNA and proteins and to increase cell wall strength by increasing peptidoglycan corsslinking

gram +

have thicker cell (peptidoglycan)

growth phases

lag, exponential, stationary, death

what happens in exponential phase?

OD and viable count is parallel. higher the density, higher the cells

microbiome

the entire collection of microscopic organisms and their shared environment (includes both biodiversity and biomass)

all the microbes in one location

biodiversity

variety of different life forms

biomass

total weight of the life forms

nitrogen fixation

N2 to NH3 with nitrogenase (source is from atmosphere)

rhizobium

symbiotic nitrogen fixer commonly associated with legumes

ammonification

make NH3

nitrification

make NH4, NO2, NO3

assimilation

make proteins, nucleic acids, etc for organism

denitrification

N2 in atmosphere (cycles)

anammox reactions

N2 in atmosphere only by prokaryotes

mutualism

bacteria in the human colon

(everyone wins)

commensalism

mites in human fair follicles

(one wins, one unaffected)

amensalism

fungus, or an algal bloom that releases toxins into water that can harm fish and animals

(one loses)

parasitism

tuberculosis, bacteria in human lung, medical conditions

(one wins and one loses)

mutualism

(everybody wins)

rhizobia and legumes (soybeans/plants)

rhizobium enters through plants root hairs and forms root nodules

• rhizobium gets a place/resources

• plant benefits from nitrogen fixation

resident microbiota

(commensal)

microbes that live with you for long periods of time

transient microbiota

(can be involved in causing disease)

temporarily there

characterization of the microbiota of 5 major body sites

• nose

• mouth

• skin

• gut

• urogenital

fecal microbiota transplantation (FMT)

(poo replacement therapy)

success in treating clostridium difficile infections, colitis, inflammatory bowel disease

aerobes

obligate (need oxgyen),

facultative (dont need but like oxygen)

micoraerophilic (need little oxygen)

anaerobes

aerotolerant (doesnt require oxygen,and doesnt kill),

obligate (harmful or lethal)

psychrophile

cold loving, 4

polaromonas vacuolata

adaptation to life in the cold

mesophile

moderate temp, 37

e coli

thermophile

heat loving, 60

geobacillus stearothermophilus

adaptation to live at high temps

hyperthermophile

very high temp, 88/106

thermococcus celer, pyrolobus fumarii

halophiles

salt tolerant, only the halobacterium salinarum survives in extreme hydrophile

acidophile

outside can be extremely acidic/low pH = maintains internal pH above 4.6

aklaliphile

outside can be extremely basic = maintain internal pH below 9.5