Unknown Organism

[CheriPeace]

I need help identifying my unknown by Monday.

Here are the results.


1. Gram Stain Positive (Clustered Bacilli)
2. Capsule Negative
3. Endospore Negative*
4. Phenol Red Broth Fermentation with Acid and Gas end products
5. Nitrate Reduction NO3 --> NO2
6. Urea Hydrolysis Does not produce urease or cannot live in broth
7. Methyl Red No mixed acid fermentation
8. Voges-Proskauer Acetoin is not produced
9. Oxidase Cytochrome c Oxidase is present
10. Catalase Catalase is present
11. Starch Hydrolysis *No amylase is present*
12. Citrate Citrate is utilized
13. Phenylalanine Phenylalanine deaminase is present*
14. SIM Medium Sulfur is not reduced, Tryptophan is not broken down, and organism is motile
15. LIA Ferments dextrose only, no lysine deaminase*
16. TSI Ferments dextrose, lactose and/or sucrose

I am 95% positive it is a facultative anaerobe. The ones marked with a "*" I am not completely sure about... My partner and I had varying opinions. Explanations are requested. My micro is a 5 week course and so I am sure I missed some important things. Please help!

[david23]

dont you have a chart that narrows these things down.

[CheriPeace]

@David23
Nope. My professor didn't even explain what the tests meant. All studying has to be done by the student. It's a 5 week course so he must have a lot of other things to worry about.

[Atropa]

Where did you get your sample from and how was it collected? Also, Bergy's Manual is what you need access to, it is a huge book that has results charts and descriptions of various species types... You should have access to it at your school, check your laboratory or the library.

[triton]

amplify 16S rDNA by using universal primer pair and sequence it. Then use the blast tool at NCBI and compare your sequence with the database...and you will know better than from performing these bacteriological tests.

[Cat]

It seems to be some kind of Bacillus species...