Natural environments usually are not homogeneous, but highly structured, even on a microscopic scale. Very often the amount of nutrients or of e.g. light changes rapidly over a very small distance. Here are some organisms that live in a gradient of sulfide and air, or at the surface of water.
You are welcome to download the images. Annotations are included. If you want to see them first, click on
|
|
|
|
|
|
Beggiatoa spec tends to form white mats on top of sulfide-rich sediments. Here, long filaments at the edge of such a mat can be seen. The filaments have a diameter of about 10 µm.
Phase contrast micrograph
ann |
|
|
|
|
|
|
|
Single filaments of Beggiatoa spec. At theirs ends the filaments sometimes divide into smaller, coccoid cells.
The colony developed in the lab on a sulfide rich marine sediment from the Eel Pond, Woods Hole, MA, USA
Phase contrast micrograph.
Bar: 20 µm
ann |
|
|
|
|
|
|
|
|
Single filaments of Beggiatoa spec. The bacteria life from the oxidation of sulfide with oxigen. The elemental sulfur formed is deposited in the cells and is evident as bright yellow granules.
Phase contrast micrograph.
Bar: 20 µm
ann |
|
|
|
|
|
|
Thiovulum spec. forms narrow veils at the interface between sulfide and oxigen in marine water columns. With a speed of 600µm/sec it is one of the fastest bacteria known. The cells oxidize sulfide with oxigen and deposit sulfur inside. Sinlge cells have a diameter of about 20 µm. Pure cultures do not exist.
Phase contrast micrograph.
ann |
|
|
|
|
|
|
|
Bacteria on the surface of undisturbed water form highly ordered structures. Here is a sample from the surface film of a bucket of sea water.
DIC micrograph
Bar: 20 µm
ann |
|
|
|
|
|
|
|
|
Here is another example of a surface film. The bacteria form some slimy material that holds them together.
DIC micrograph.
Bar: 20 µm
ann |
|
File |
Size
Bytes
pixels |
Annotations |
|
begg1_bg.jpg |
117K
508x480 |
Beggiatoa spec. Filaments at the edge of a microbial mat. Beggiatoa lives from sulfide and air.
Diameter of a filament: about 10 µm
Phase contrast micrograph.
Copyright 1997 Microbial Diversity, Rolf Schauder |
|
beggia02_bg.jpg |
97K
508x480 |
Beggiatoa spec.
Single filaments of the gliding bacterium. The bright spots in the cell are sulfur granules.
Phase contrast micrograph.
Copyright 1997 Microbial Diversity, Rolf Schauder |
|
beggia06_bg.jpg |
126K
508x480 |
Single filaments of Beggiatoa spec. The bacteria life from the oxidation of sulfide with oxigen. The elemental sulfur formed is deposited in the cells and is evident as bright yellow granules.
Phase contrast micrograph.
Copyright 1997 Microbial Diversity, Rolf Schauder |
|
thiovul5_bg.jpg |
96K
508x480 |
Thiovulum spec. forms narrow veils at the interface between sulfide and oxigen in marine water columns. With a speed of 600µm/sec it is one of the fastest bacteria known. The cells oxidize sulfide with oxigen and deposit sulfur inside. Sinlge cells have a diameter of about 20 µm. Pure cultures do not exist.
Phase contrast micrograph
Copyright 1997 Microbial Diversity, Rolf Schauder |
|
seatab04.jpg |
23K
508x480 |
Bacteria on the surface of undisturbed water form highly ordered structures. Here is a sample from the surface film of a bucket of sea water.
DIC micrograph
Copyright 1997 Microbial Diversity, Rolf Schauder |
|
seatab03.jpg |
26K
508x480 |
Bacteria from the surface film of a bucket of sea water. The microbes form a slime that holds them together.
DIC micrograph.
Copyright 1997 Microbial Diversity, Rolf Schauder |
