2. Series of Tables
STEP # 1 for species known as C11
NAME OF TEST Gram Stain
MEDIUM NA
INCUBATION (if applicable) NA
SPECIAL PROCEDURE(S) (if applicable) NA
REAGENT(S) USED & AMOUNT (if applicable) Crystal violet, Gram’s iodine, decolorizer, safranin
APPEARANCE OF RESULTS
Bacteria are stained pink in color, are bacilli in
shape
RESULT (positive or negative, and for what) Gram-negative bacilli
INTERPRETATION (what do the results mean?)
This particular species lacks a thick peptidoglycan
layer, which means that they cannot be
BACTERIA OR SPECIES ELIMINATED
All Gram-positive species; Gram-negative cocci
species
WHY ELIMINATED?
Gram-positive species stain purple, Gram-negative
cocci are different in shape
POSSIBILITIES REMAINING Gram-negative bacilli
STEP # 2 for species known as C11
NAME OF TEST Mobility Test
MEDIUM Semi-solid agar
INCUBATION (if applicable) 6 days at room temperature (RT)
SPECIAL PROCEDURE(S) (if applicable) NA
REAGENT(S) USED & AMOUNT (if applicable) NA
APPEARANCE OF RESULTS
Fuzzy along stab-line with bacterial growth
towards the top of the medium
RESULT (positive or negative, and for what) Bacteria tests positive for motility
INTERPRETATION (what do the results mean?)
This species is capable of moving through the
semi-solid agar, confirming that the bacteria have
flagella.
BACTERIA OR SPECIES ELIMINATED
All Gram-positive species; Non-motile, Gram-
negative bacilli and cocci
WHY ELIMINATED?
The bacteria known as C11 are motile, Gram-
negative bacilli
POSSIBILITIES REMAINING Motile, Gram-negative bacilli
3. STEP # 3 for species known as C11
NAME OF TEST Catalase Test
MEDIUM NA
INCUBATION (if applicable) NA
SPECIAL PROCEDURE(S) (if applicable) NA
REAGENT(S) USED & AMOUNT (if applicable) Hydrogen peroxide
APPEARANCE OF RESULTS
Presence of bubbling when exposed to hydrogen
peroxide
RESULT (positive or negative, and for what) Positive for the presence of the enzyme catalase
INTERPRETATION (what do the results mean?)
This bacteria produce the enzyme catalase, which
breaks down hydrogen peroxide to water and
carbon dioxide.
BACTERIA OR SPECIES ELIMINATED
All Gram-positive species; Catalase-negative,
Gram-negative, non-motile bacilli and cocci
WHY ELIMINATED?
The species known as C11 produces the enzyme
known as catalase, and are motile, Gram-negative
bacilli
POSSIBILITIES REMAINING
Pseudomonas aeruginosa, Pseudomonas
chlororaphis, Pseudomonas fluorescens,
Pseudomonas putida, Pseudomonas cichorii, and
Pseudomonas syringae.
STEP # 4 for species known as C11
NAME OF TEST Arginine Dihydrolase Test
MEDIUM Arginine-containing medium
INCUBATION (if applicable) 6 days at RT
SPECIAL PROCEDURE(S) (if applicable) NA
REAGENT(S) USED & AMOUNT (if applicable) 1 mL of sterile mineral oil
APPEARANCE OF RESULTS The medium turned a hot pink color throughout
RESULT (positive or negative, and for what) Positive for the utilization of arginine
INTERPRETATION (what do the results mean?)
The species in question tested positive for the use
of arginine as a source for carbon and energy.
BACTERIA OR SPECIES ELIMINATED P. cichorii, P. syringae
WHY ELIMINATED?
Both of the aforementioned species cannot use
arginine as a source of carbon and energy
POSSIBILITIES REMAINING
P. aeruginosa, P. chlororaphis, P. fluorescens, P.
putida.
4. STEP # 5 for species known as C11
NAME OF TEST Glucose Oxidation Test
MEDIUM Hugh & Leifson’s O/F Glucose Agar
INCUBATION (if applicable) 2 days at RT
SPECIAL PROCEDURE(S) (if applicable) Stab inoculation with heavy inoculum
REAGENT(S) USED & AMOUNT (if applicable) NA
APPEARANCE OF RESULTS Yellow discoloration at the top of the medium
RESULT (positive or negative, and for what) Positive for the utilization of glucose
INTERPRETATION (what do the results mean?)
The species in question tested positive for the use
of glucose as a source of carbon.
BACTERIA OR SPECIES ELIMINATED None
WHY ELIMINATED?
No species were eliminated. P. aeruginosa, P.
chlororaphis, P. fluorescens, and P. putida all test
positive for the use of glucose as a source of
carbon
POSSIBILITIES REMAINING
P. aeruginosa, P. chlororaphis, P. fluorescens, P.
putida.
STEP # 6 for species known as C11
NAME OF TEST Arabinose Oxidation Test
MEDIUM Hugh & Leifson’s O/F Arabinose Agar
INCUBATION (if applicable) 2 days at RT
SPECIAL PROCEDURE(S) (if applicable) Stab inoculation with heavy inoculum
REAGENT(S) USED & AMOUNT (if applicable) NA
APPEARANCE OF RESULTS Yellow discoloration at the top of the medium
RESULT (positive or negative, and for what) Positive for the utilization of arabinose
INTERPRETATION (what do the results mean?)
The species in question tested positive for the use
of arabinose as a source of carbon.
BACTERIA OR SPECIES ELIMINATED P. chlororaphis, P. putida
WHY ELIMINATED?
The previously mentioned species are incapable of
using arabinose as a source of carbon
POSSIBILITIES REMAINING P. aeruginosa, P. fluorescens
5. STEP # 7 for species known as C11
NAME OF TEST Gelatinase Test
MEDIUM Nutrient Gelatin Agar Deep
INCUBATION (if applicable) 2 days at 28o
C
SPECIAL PROCEDURE(S) (if applicable) NA
REAGENT(S) USED & AMOUNT (if applicable) NA
APPEARANCE OF RESULTS Solid throughout with no trace of liquid
RESULT (positive or negative, and for what) Negative for the production of gelatinase
INTERPRETATION (what do the results mean?)
The species in question does not produce the
enzyme gelatinase.
BACTERIA OR SPECIES ELIMINATED None
WHY ELIMINATED?
P. aeruginosa tests positive for the production of
gelatinase, and P. fluorescens can give inconclusive
positive or negative results
POSSIBILITIES REMAINING P. aeruginosa, P. fluorescens
STEP # 8 for species known as C11
NAME OF TEST Nitrate/Nitrite Reduction Test
MEDIUM Nitrate broth
INCUBATION (if applicable) 2 days at RT
SPECIAL PROCEDURE(S) (if applicable) NA
REAGENT(S) USED & AMOUNT (if applicable)
15 drops of “Nitrate A”, 15 drops of “Nitrate B”,
zinc
APPEARANCE OF RESULTS
No color change after nitrate A and nitrate B were
added to the broth. After zinc was added, the
broth turned a deep red and produced no gas
RESULT (positive or negative, and for what)
Negative for nitrate reductase and negative for
nitrite reductase
INTERPRETATION (what do the results mean?)
The species does not reduce nitrate to nitrite and
does not reduce nitrite to nitrogen gas or ammonia
BACTERIA OR SPECIES ELIMINATED P. aeruginosa
WHY ELIMINATED?
P. aeruginosa tests positive for both nitrate
reductase and nitrite reductase
POSSIBILITIES REMAINING P. fluorescens
Conclusion
Unknown species “C11” is Pseudomonas fluorescens.
