MBIO 3401 EXAM ONE ZHANG
COMPREHENSIVE EVALUATION 2026
VERIFIED SOLUTIONS GRADED A+
⩥ facultative anaerobe. Answer: both aerobic and anaerobic growth;
greater growth in presence of oxygen
⩥ obligate anaerobe. Answer: only anaerobic growth; cannot grow in
presence of oxygen
⩥ aerotolerant anaerobe. Answer: anerobic growth; but growth continues
in presence of oxygen
⩥ microaerophilic. Answer: aerobic growth; oxygen required in low
concentration
⩥ capnophilic. Answer: aerobic growth; CO2 required in high
concentration
⩥ Anaerobic Growth Methods. Answer: -anaerobic chamber
-anaerobic "jars"/sealed boxes
-OxyPlate
-Anoxomat
,⩥ Anaerobic chamber. Answer: -materials put into air-lock chamber
through small doors
-operator works through arm ports in airtight sleeves
-chamber filled with 85% N2, 10% H2, and 5% CO2
-not often used anymore
⩥ Anaerobic "jars"/sealed boxes. Answer: -chemical packet containing
sodium bicarbonate and sodium borohydride mix with water to make
hydrogen and CO2 in tightly sealed jar
-catalyst = palladium
-anaerobic indicator placed in jar for monitoring of atmospheric
conditions
⩥ OxyPlate. Answer: -petri plate itself becomes anaerobic chamber
-culture medium contains oxyrase enzyme that combines oxygen with
hydrogen to form water
⩥ Anoxomat. Answer: -jar evacuation and replacement system
-80% N2, 10% H2, 10% CO2
-convenient and cost effective
⩥ Anaerobic indicators. Answer: -oxidation-reduction indicator
,-methylene blue (blue) or resazurin (pink) turn colorless under anaerobic
conditions
⩥ Anaerobic blood agar. Answer: -CDC
-general purpose medium for all anaerobic bacteria
-enriched
⩥ Bacteroides bile esculin agar. Answer: -BBE
-isolates Bacteroides fragilis group
-selective: bile
-differential: hydrolyzation of esculin (black color)
⩥ Kanamycin-vancomycin laked sheep blood agar. Answer: -KVL
-isolates Bacteroides sp. and Prevotella sp.
-selective: prevents growth of facultative bacteria
-differential: Laked blood enhances pigment formation
⩥ Phenylethyl alcohol agar. Answer: -PEA
-isolates most anaerobic organisms
-selective: inhibits faculative anaerobic gram negative bacteria (ex:
enterobacteriaceae)
, ⩥ Colistin Nalidixic Acid agar. Answer: -CNA
-isolates most gram positive anaerobic and facultative anaerobic bacteria
-selective: inhibits gram negative organisms
⩥ Egg yolk agar. Answer: -isolates Clostridium sp.
-selective: detects proteolytic enzymes (lipase and lecithinase)
⩥ Broths with reducing agents. Answer: -can grow anaerobic bacteria
-thioglycollate broth
-"cooked meat" broth
⩥ Aerotolerance testing. Answer: -tests to see if colony is anaerobic
-BAP incubated anaerobically
-CAP incubated with increased CO2
-isolates growing only on BAP plate are "obligate anaerobes"
-isolates growing better on BAP than CAP are "aerotolerant anerobes"
⩥ Bacteroides fragilis. Answer: -gram negative coccobacilli
-B. fragilis = most common
-B. thetaiotaomicron = 2nd most common
-normal flora of colon
COMPREHENSIVE EVALUATION 2026
VERIFIED SOLUTIONS GRADED A+
⩥ facultative anaerobe. Answer: both aerobic and anaerobic growth;
greater growth in presence of oxygen
⩥ obligate anaerobe. Answer: only anaerobic growth; cannot grow in
presence of oxygen
⩥ aerotolerant anaerobe. Answer: anerobic growth; but growth continues
in presence of oxygen
⩥ microaerophilic. Answer: aerobic growth; oxygen required in low
concentration
⩥ capnophilic. Answer: aerobic growth; CO2 required in high
concentration
⩥ Anaerobic Growth Methods. Answer: -anaerobic chamber
-anaerobic "jars"/sealed boxes
-OxyPlate
-Anoxomat
,⩥ Anaerobic chamber. Answer: -materials put into air-lock chamber
through small doors
-operator works through arm ports in airtight sleeves
-chamber filled with 85% N2, 10% H2, and 5% CO2
-not often used anymore
⩥ Anaerobic "jars"/sealed boxes. Answer: -chemical packet containing
sodium bicarbonate and sodium borohydride mix with water to make
hydrogen and CO2 in tightly sealed jar
-catalyst = palladium
-anaerobic indicator placed in jar for monitoring of atmospheric
conditions
⩥ OxyPlate. Answer: -petri plate itself becomes anaerobic chamber
-culture medium contains oxyrase enzyme that combines oxygen with
hydrogen to form water
⩥ Anoxomat. Answer: -jar evacuation and replacement system
-80% N2, 10% H2, 10% CO2
-convenient and cost effective
⩥ Anaerobic indicators. Answer: -oxidation-reduction indicator
,-methylene blue (blue) or resazurin (pink) turn colorless under anaerobic
conditions
⩥ Anaerobic blood agar. Answer: -CDC
-general purpose medium for all anaerobic bacteria
-enriched
⩥ Bacteroides bile esculin agar. Answer: -BBE
-isolates Bacteroides fragilis group
-selective: bile
-differential: hydrolyzation of esculin (black color)
⩥ Kanamycin-vancomycin laked sheep blood agar. Answer: -KVL
-isolates Bacteroides sp. and Prevotella sp.
-selective: prevents growth of facultative bacteria
-differential: Laked blood enhances pigment formation
⩥ Phenylethyl alcohol agar. Answer: -PEA
-isolates most anaerobic organisms
-selective: inhibits faculative anaerobic gram negative bacteria (ex:
enterobacteriaceae)
, ⩥ Colistin Nalidixic Acid agar. Answer: -CNA
-isolates most gram positive anaerobic and facultative anaerobic bacteria
-selective: inhibits gram negative organisms
⩥ Egg yolk agar. Answer: -isolates Clostridium sp.
-selective: detects proteolytic enzymes (lipase and lecithinase)
⩥ Broths with reducing agents. Answer: -can grow anaerobic bacteria
-thioglycollate broth
-"cooked meat" broth
⩥ Aerotolerance testing. Answer: -tests to see if colony is anaerobic
-BAP incubated anaerobically
-CAP incubated with increased CO2
-isolates growing only on BAP plate are "obligate anaerobes"
-isolates growing better on BAP than CAP are "aerotolerant anerobes"
⩥ Bacteroides fragilis. Answer: -gram negative coccobacilli
-B. fragilis = most common
-B. thetaiotaomicron = 2nd most common
-normal flora of colon
