Microbio Lab 5/6/7: Media and their results

Blood agar results

beta hemolysis: complete hemolysis (has enzyme hemolysin)

Blood agar results

alpha hemolysis: partial hemolysis

Blood agar results

gamma hemolysis: no hemolysis (does not have enzyme hemolysis)

Mannitol Salt Agar (MSA) results

top: positive for salt tolerance, but negative for fermentation of mannitol

bottom: positive for salt tolerance AND ferments mannitol

Nutrient agar (left) and Phenylethyl Alcohol agar (PEA)

PEA: if growth, bacteria is gram (+)

if no growth, bacteria is gram (-)

Eosin Methylene Blue Agar (EMB) results

Positive for *vigorous* lactose fermentation

(will have green shine)

Eosin Methylene Blue Agar (EMB) results

*little* lactose fermentation lactose (will appear purple)

Eosin Methylene Blue Agar (EMB) results

non-lactose fermentation

(normal color)

Catalase test

negative (bacteria does not have catalase)

Catalase

positive (bacteria has catalase)

coagulase test

negative (bacteria does not have coagulase)

coagulase test

positive ( bacteria does have coagulase)

Phenol red broth

negative for *both* acid and gas production

Phenol red broth results

* acid (+) \[bc yellow\]
* gas (-) \[bc no gas in durham tube\]

Phenol red broth results

* acid (+) \[bc yellow\]
* gas (+) \[bc gas in durham tube\]

Phenol Red Broth

* acid (+)
* gas (+)
* but!!! left incubated for longer than 24hrs so bacteria started using protein as energy source instead of carbohydrates

Simmon’s carbon result

left: (+) for enzyme citrase (can use citrate)

right: (-) for enzyme citrase (cannot use citrate)

Triple Sugar Iron Agar (TSIA)

* red slant (Absence of carbohydrate fermentation)
* red butt (Absence of carbohydrate fermentation)
* no gas formation
* no hydrogen sulfide (H2S)

Triple Sugar Iron Agar (TSIA)

* red slant (dextrose fermentation only)
* yellow butt (dextrose fermentation only)
* (-) gas production
* No hydrogen sulfide (H2S)

Triple Sugar Iron Agar (TSIA)

* Yellow slant (fermentation of dextrose, lactose and/or sucrose)
* yellow butt (fermentation of dextrose, lactose and/or sucrose)
* (+) gas formation (cracks)
* (-) for hydrogen sulfide (H2S) (not black media)

Triple Sugar Iron Agar (TSIA)

* yellow slant (fermentation of dextrose, lactose and/or sucrose)
* black butt
* (+) for gas (cracks)
* (+) for hydrogen sulfide (black media)

Triple Sugar Iron Agar (TSIA)

* red slant (dextrose fermentation only.)
* black butt
* (+) for gas formation
* (+) for hydrogen sulfide (H2S)

Bile Esculine Agar (BEA) results

(-) for esculinase in bacteria

Bile Esculine Agar (BEA) results

(+) for esculinase in bacteria // meaning will hydrolyze esculine in bile

Sulfur reaction results

(+) for hydrogen sulfide (breaks down sulfide)

indol reaction results

(+) for indol (bacteria has tryptophanase)

Motility Reaction results

(+) for motility \\\\ hazy, turbid looking

Motility Reaction results

(-) motility, bacteria is only grown where stab line is

Sulfur Reduction Indol Production Motility

* (-) sulfur
* (+) Indol (red color on top due to kovac reagent))
* (+) motility

Sulfur Reduction Indol Production Motility

* (-) sulfur
* (-) Indol
* (+) motility

Sulfur Reduction Indol Production Motility

* (+) sulfur (black media)
* (-) Indol
* (+) motility (assume since it is black)

Urea results

(-) does not have urease

Urea results

(+) has urease, (urea break down causes alkaine enviorment )