Re: Can Bacteria Digest and Metabolize Lipids?


JEDilworth wrote:
I work on anaerobic cultures a lot. Certain organisms really do stink.
Some are so bad we haul out air deodorizers after opening our anaerobe
jars, or burning our wooden mixing sticks for an instant, blowing them
out, and waving the smoking wood in the air to cover up the smell. You
just get used to it.

I've had organisms that smell like familiar bad smells; one Clostridium
sp. I isolated (I don't remember which one now, but it wasn't C.
perfringens) smelled EXACTLY like cow manure. This is obviously the
organism that causes cow poop to smell like it does. It may have been
Clostridium sporogenes but don't quote me.

Another organism I've isolated is Fusobacterium nucleatum - this one
smells like morning breath in humans. We have many bacteria in the
crypts of our gums, and this includes many species of Fusobacteria.
People with bad gums probably have a worse problem. What you smell on
bad breath is obviously partly the byproducts of bacterial metabolism.

Aerobic bacteria also have distinctive smells. I've gotten so I can tell
most of the common enterics by smell. We're not "officially" supposed to
smell bacteria, but many microbiologists rely on smell as an adjunct to
identifications. Obviously, Proteus mirabilis stinks very badly, and
also has a characteristic swarm over the plate. Last night, I had a
Proteus in a specimen I hadn't gotten to yet, but I could smell it WAY
before I got to the plates. Citrobacters, E. coli, Pseudomonas
aeruginosa, Pasteurella multocida, Bacteroides fragilis (an anaerobe),
ALL have distinctive odors. When asking advice from another tech about
identification, we frequently talk about how the bug smells. Hemophilus
smells "mousey." Strep viridans group has a very distinctive smell
depending on which one it is. Coagulase negative Staphylococci smell
like chocolate cake, according to a tech I worked with. I can tell on a
mixed anaerobic culture plate if there's an anaerobe on it to be
isolated just from the smell of the plate, as they distinctively smell
worse than plates with just aerobes that grow anaerobically.

The earthy smell referred to in another post is usually due to
Streptomyces sp. (a fungus). You don't want to go sniffing that kind of
stuff too closely. Some fungi have spores that can cause disease in
humans if you're either immunocompromised or there's just a huge
concentration of spores in an enclosed space.

I guess after 31 years all of this kind of becomes part of your job :-).
People that don't work in micro just don't understand....:-).

Judy Dilworth, M.T. (ASCP)
Microbiology

One correction, Streptomyces sp are bacteria. They are members of the
order Actinomycetaceae which contains, amongst others, the generas
Actinomyces, Corynebacterium, Frankia, Mycobacterium and Streptomyces.

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