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Unknown microscopic life

  1. May 26, 2013 #1
    A while back I managed to get (2) very nice surplus Nikon microscopes from UC Davis (CA). Since then I have taken several grass root and compost samples from my yard and mulch pile and cultured them in glass bottles with purified drinking water.

    I wind up with all kinds of life forms that are not too difficult to classify, but often I get thousands of VERY small, fast-moving life forms. By very small I mean I have to get out the immersion oil and to do a setup for 1000X in order to see any detail. At 400X they are essentially small dots zooming about. At 1000X I can just see that they are somewhat elongated and have just a few dark round spots in their interior.

    It takes about a week plus for them to come out in the "culture," but when they do a single small drop under a cover glass has what must be a thousand of them. I get no indication that they are juveniles of some of the other larger life in the jars, as the number of larger ones does not increase over time.

    I'm a retired electronics guy and the last time I took biology was in high school, so I could really use any information as to what these are or any guidance as to where I could go for further information on such things. Thus far the photos and info online don't seem to match with these little guys.

    Any help appreciated, and by the way, I am having a good time using the microscopes; they are really beautiful pieces of equipment from the '70's.

  2. jcsd
  3. May 26, 2013 #2

    Andy Resnick

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    Could be e. coli or some other bacteria; can you post pics?
  4. May 27, 2013 #3
    Thanks for the reply, but I don't think it would be possible to get a picture of them while alive as they move VERY fast and the scope isn't set up for photos. Furthermore killing them without turning them into plasma-goop is beyond my skills at this point. The best I might be able to do is a make a drawing of what little detail I can see.

    As to the bacteria thing, the ones I have seen are pretty sedentary. These little guys really move. They are about the same size though. We are talking down at the very limit of the X1000 to discern any detail.

    At the present I doubt, as I said, that they are juveniles of a more "normal" sized adult, but it is still possible.
    I will try to optimize the lighting and make a drawing with as much detail as I can. Hopefully they will not croak on me before I can get the job done.
  5. May 27, 2013 #4


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  6. May 27, 2013 #5
    Extreme difference in size. I get what I identify as paramecia (?) from the local reservoir and sometimes from back yard samples. Much bigger. "50 to 300 microns" per Wiki. A paramecium looks big at X400 while these guys are just tiny dots.

    Just finished making some drawing notes and I can say they are much harder to see with any detail at X1000 than I thought before. Will try to get some graphics here tomorrow.
    Last edited: May 27, 2013
  7. May 27, 2013 #6


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    I had my doubts about the size, hence the disclaimer :frown:
  8. May 27, 2013 #7


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    There are bacteria that are very mobile and will zip around on a slide. Most of the pseudomonads, bacillus sp, tons of gram negative rods, etc.

    What would be best is if you could do a gram stain and see what they look like.

    It isn't useful to look at unstained bacteria if you are trying to figure out what they are. You really need to sacrifice them and stain them. Which is really the first step to identifying any bacteria.
  9. May 27, 2013 #8
    OK, thanks for the informative input. Thus far my biology lab is limited to microscopes, slides, cover glasses, immersion oil and some other accessories. Staining would be a whole new ball game for me. I did not realize that some bacteria are very mobile. All the ones I have observed so far, such as common root bacteria just lay there quietly.

    I shall have to check into more advanced techniques like staining, but I doubt, on these at least, if I will be able to see very much at my max of X1000.

    I'll also look into the classifications you mention to see if any pix look like what I am seeing. In the meantime there should be an attached photo of the sketches I made last night, if the process worked. These are what I THINK I saw, so don't hold me to it. At least now I know that they could be bacteria and that is almost enough for me, at least for now.

    Attached Files:

  10. May 27, 2013 #9
    Looks a lot like these, except negative/reversed contrast. Pseudomonas Resinovorans.

    Attached Files:

  11. May 28, 2013 #10


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    I would also guess that they are bacteria. The fast motion is probably not active motion but Brownian motion
    . You could reduce it by increasing the viscosity of the medium (e.g. some gelatineous medium).
  12. May 28, 2013 #11
    If you can see them unstained, then you could try just fixing them with a flame, which is very easy to do. Just wave the slide over an open flame carefully so you evaporate the water without boiling it.
  13. May 28, 2013 #12
    aroc91, I have seen other animalcules disintegrate as they dry, but I will try something similar first. We have very low humidity here and the liquid at the edge of the cover glass dries very quickly. I will just let a slide with the cover glass and sample sit for a while. I can try the heat too.

    DrDu, don't think it is Brownian movement as I can see they are moving in a controlled wiggle, and sometimes they rotate, and appear to be investigating a debris area as if looking for food. I should not be surprised if they have very thin flagella.

    Again thanks for the info gentlemen.
  14. May 29, 2013 #13
    I let a slide with cover glass and sample dry for a while, and most of them were not moving. They do in fact look almost exactly like the drawing that I posted above. They tend to be more like the "rounded" example but they do assume the other shapes in the dry/dead form. There was at least one with 6 of the round dark spots. Most had just 3 or 4 visible.

    Not very much to see with the 1000X limit of the microscope, and tricky to get a good view. Would be interesting to find their role in the overall biological scheme of things.
  15. May 29, 2013 #14


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    Its really not possible to identify bacteria without staining and biochemical testing (which can be done with something like API or on plating).

    Just looking at unstained bacteria will tell you basically if they are cocci or rods (also called bacillus, but that can get confusing because there is a rod shaped gram positive genus bacterial called Bacillus), but that is about as close as you can get to figuring out what they are.

    Any identification algorithm for bacteria starts off with a gram stain, followed by cellular morphology. That's really the first steps you need to do if you intend to identify them.
  16. May 29, 2013 #15
    Thank you.
    Evidence/information/things are pointing towards Pseudomonas Fluorescens just now. More later after one test I have to do.
  17. Jun 4, 2013 #16
    Well, I guess that wasn't it. It's not easy being green.
  18. Jun 7, 2013 #17
    Latest is that Nematodes Elaphonema have sprung up in the sample in rather large numbers and I would assume they are having a feast on the bacteria. They sure are fat and healthy looking.

    Saw my first Amoeba this afternoon in this same sample. I was using shadow/indirect lighting and at first I thought it was a carcass with bacteria running around on it. Then it moved Veryyyyy---slowly. chuckle.

    A friend who is really into photography and I are discussing various ways to set up for micro-photography. I was for years heavy into film cameras, but have been putting off getting a good quality digital one for some time. Holy moly, camera adapters cost almost as much as a nice SLR.

    Guess it is about time to go ahead and get a good camera that I can use for microscope and some aerial photography. Been wanting to do that, too.
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