Microbiology List: FW: Re: Microbiology List: FW: microorganisms in fish tanks

Richard Oeffner roeffner at csusm.edu
Wed Mar 14 17:13:41 EST 2001

Just wanted to mention that for the salt water bacteria, which I have 
done a lot of research in for formulations and ideas,  the standard MA 
2216 may be too rich in nutrients for isolation of many marine bacteria. 
In some cases, it may be that Yeast Extract is actaually toxic to marine 

I am currently comparing a media similar to MA 2216, 1/100th MA 2216 and 
a formulation I came up with using fish peptone/spirulina powder/fish 
emulsion(FPES). From preliminary analysis of colony morphology, it seems 
the 1/100th and FPES have a much wider range of colony morphologies...am 
trying to get funding to actually do some genetic analysis to prove this.

I would suggest using the MA 2216, and maybe a 1/100th concentration of 
it...you might get a wider range of colony types from the low nutrient 


Yersinia wrote:

> Tanya Kuritz writes,
> <Yersinia:
>         Glad to hear from you!  Unfortunately, very few schools, to my
> knowledge, are capable of guiding students in microbiology.  Isolation of
> representative microorganisms from fish tanks is a tricky task even for a
> seasoned microbiologist: enrichment that is necessary to see 
> microorganisms
> will decrease their diversity.  There are several major, distinct groups 
> in
> freshwater tanks to look for (and to enrich for):
> (1) oligotrophs that will grow on R2A or on tap water with dilute vitamins
> (Wolfe's vitamins at 1:10 to 1:100); (2) conventional dear-to-our-heart
> heterotrophs that will be happy on LB or TSB; and my best beloved (3)
> cyanobacteria growing which is a pain as they are very finicky in regards 
> to
> media and even require specially-purified agar.  BG11 or Gromov's media
> would be my first choice.
>         Salt-water tanks will hold a number of good heterotrophs that 
> would
> easily grow on solidified Marine Broth 2216.  Many of those will belong to
> Vibrio or to different spirilla genera (e.g. Oceanospirillum etc.).  Those
> will be equally happy in LB or TSB.  (Presumed) nitrogen-fixing (or 
> rather,
> nifH-gene bearing) heterotrophs that are usually associated with cyanos 
> will
> grow on MB2216.  Growing marine cyanos is a hard task, but some may grow 
> in
> BG11 marine supplemented with vitamins.
>         Many of oligotrophs and cyanobacteria will be slow-growers, and
> growing them will require a stretch of time well beyond one semester.  
> Even
> if everything grows, identification of benign bacteria, especially cyanos,
> is science of its own. 
>         Within one semester, Dutch should be able to grow some 
> heterotrophic
> microorganisms provided that s/he will have access to a micro lab.  
> Yersinia
> has listed equipment and supplies needed for this endeavor.  Good luck!>
> Oh, I've been around on this list, although I haven't posted much lately. 
> But Dutch's proposed study did fascinate me. I'll thank YOU, Tanya, for 
> the mention of the media to be used in enriching and growing the bugs 
> from the saltwater samples. Though I've done plenty of water testing (in 
> pharmaceutical and cosmetic company labs), actual marine microbiology is 
> out of my league; I haven't done any. The closest I ever got was when I 
> sampled water from the pond in the park next door to my apt. building, 
> brought the sample to work and attempted to isolate and ID the bugs. In 
> fact, when I tried to answer Dutch's question, I went through both my 
> Difco Manual (hey, I did look for the Marine broth and couldn't find it!) 
> and my Bergey's to get an idea of what to recommend, and hoped he/she 
> wouldn't ask for a recipe. And I'm ashamed to admit, I didn't even think 
> of the cyanos or nitrogen fixers. Hey, I got a question for you, Tanya:
> I'm positive that no high school science lab would have a Vitek or API 
> strips on hand, and I doubt either of those systems would be of much use 
> in ID'ing many of the bugs found in the fishtanks, BUT....they do have 
> the chemical reaction wells, so do you think it would be possible to just 
> run the "weird" bugs through and use a combination of cell morphology as 
> seen through the microscope with the lists of reactions in Bergey's to 
> make the ID at least to genus level? For instance, a bug that ferments 
> glucose will still ferment the glucose in an API strip, even if the rest 
> of the reactions on the strip produce an ID not found in their database 
> (but might be used with that Bergey's to make, or disprove an ID)? Just 
> my own curiosity on this one, mind you - I doubt this will help Dutch, 
> and even my COLLEGE micro lab didn't have a Vitek or API strips, and we 
> never came close to doing anything like this in the course.
> ~Yersinia.
> ---

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