differential media - ✔️✔️allow certain bacteria to be differentiated from others, typically
by change in color, production of clearing zones
general purpose media - ✔️✔️supports growth of wade range of organisms (nutrient
broth, nutrient agar, tryptic soy broth)
gram negative - ✔️✔️pink rods
endospore - ✔️✔️responses to certain environmental conditions such as depletion of
nutrients
stages of growth curve: - ✔️✔️lag, exponential (log), stationary, death
lag phase - ✔️✔️occurs when culture is transferred to fresh growth medium
exponential phase - ✔️✔️growth is maximal and at a steady rate, culture is stable both
chemically and physically
gram positive - ✔️✔️purple cocci
stationary phase - ✔️✔️cell division of new cell growth is matched by equal amount of
cell death
death phase - ✔️✔️caused by accumulation of toxic waste products, cell damage from
exposure, of chemicals in the environment
absorbance - ✔️✔️change in optical density
generation time - ✔️✔️time required by populations to double in number
CHNOPS - ✔️✔️carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur
liquid media - ✔️✔️to grow large number or organisms (nutrient broth)
solid media - ✔️✔️used to examine colony morphology of organisms and to help
isolate pure cultures
complex media - ✔️✔️chemical composition is unknown
synthetic media - ✔️✔️made of strict list of inorganic compounds and carbon sources
, selective media - ✔️✔️media that selects for a certain type of microbe by providing
optimal conditions for its growth
exoenzymes - ✔️✔️enzymes that are secreted by cells into their environment
3 common exoenzymes - ✔️✔️amylase, caseinase, gelatinase
hydrolysis - ✔️✔️breakdown of complex molecules
amylase - ✔️✔️catalyzes starch hydrolysis
caseinase - ✔️✔️hydrolyzes milk protein (casein) into peptides and amino acids
gelatinase - ✔️✔️breaks down gelatin
catalase - ✔️✔️protects cells from hydrogen peroxide
oxidase - ✔️✔️indicates presence of cytochrome c
amylase test - ✔️✔️red growth= positive
plain growth = negative
caseinase test - ✔️✔️clearing around growth = positive
no clearing = negative
gelatinase test - ✔️✔️solid = negative
liquid = positive
catalase test - ✔️✔️bubbles = positive
no bubbles = negative
oxidase test - ✔️✔️blue color within 30 seconds = positive
clear = negative
flagellum - ✔️✔️one or more long protein filaments which rotate
brownian motion - ✔️✔️random collisions
true motility - ✔️✔️when cells move in very quick and in straight or curved paths
strict aerobe - ✔️✔️grow at surface and only slightly away from stab line, aerobic but
still motile