Bacteria ?

Jan l'Amie · Post by **Jan l'Amie** » Wed Nov 09, 2011 7:07 am

Those different types of tiny organisms I found next to a dead waterflea.
Are they all bacteria ?

Canon 50D
2.5x Photo oculair
Plan 40/0.65 Plan 25/0.40
Kreutz filter

olivier barth · Post by **olivier barth** » Wed Nov 09, 2011 12:10 pm

Hi Jan
the biggest are probably protozoa. the thin rod-shaped ones are likely bacteria (bacillus).

Jan l'Amie · Post by **Jan l'Amie** » Wed Nov 09, 2011 12:12 pm

O.K. Thanks very much for the reaction.

Franz Neidl · Post by **Franz Neidl** » Wed Nov 09, 2011 2:10 pm

I would not exclude that the bigger ones are bacteria. The bacterium Achromatium oxaliferum is 5 to 100 µm long. Therefore it would be good if you make also some measurements!

Franz

Mitch640 · Post by **Mitch640** » Wed Nov 09, 2011 5:35 pm

Nice images Jan, your oblique lighting is very even and clear.

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 10, 2011 1:18 am

Thanks. At the 3th picture you see the desmids Micrasterias crux-melitensis and Micrasterias thomasiana. Those are about 100 and 250 micron. So the biggest organisms are about 20 to 60 micron.
I think it is Achromatium oxaliferum. They look exactly the same as pictures at the internet.

For oblique light I use only my cheap and very easy to make home-made Kreutz filter.

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 10, 2011 7:23 am

A better picture.

Cactusdave · Post by **Cactusdave** » Thu Nov 10, 2011 10:15 am

That's a fascinating bacterium. Never seen anything like it. It must be as big as a decent sized ciliate, and you can clearly resolve some structure inside the cells. You are squeezing some really nice results from your setup. The low power photo ocular you have is a real bonus in a setup like this.

Mitch640 · Post by **Mitch640** » Thu Nov 10, 2011 10:28 am

I would like to see a picture of your "very easy to make home-made Kreutz filter." Getting good oblique lighting on my scope is like pulling teeth.

Jan l'Amie · Post by **Jan l'Amie** » Thu Nov 10, 2011 11:25 am

I read something about this bacteria and it is indeed a very special thing.
Now and then you see one in a sample but I've never seen so many.

This is a Kreutz filter. I made it from a piece of transparant acrylat foil with on that a piece of black sticky foil. Whit a sharp knife you have to cut a moon-shaped segment out of the black foil with the size of about 1/3 of the filter size. The diafragma whole open and you have oblique light.
Maybe you have to make another one if you not satisfied with the first result.