Tag Archives: hydrogen sulfide

Watching Bacteria Grow: Winogradsky Panel Day 7

The panel is changing more slowly now, but the oranges and greens are getting richer and the sulfur-enriched mud is showing more and coalescing black spots.
IMG_5962The level of the mud dropped overnight.  This could be due to settling of the mud and/or release of gas bubbles.  There are some water-filled gaps, and the water level is lower.  There is now air above the entire length of the water surface, instead of just at the opening of the panel (top left).  Note that there is also a left to right gradient in the water, which was already present before settling.  Near the opening, there is brownish/red colonies growing on the walls, probably aerobes (requires oxygen) explaining why its not present further from the opening.  The water is murky from left to right, perhaps microbes that can tolerate low levels of oxygen, up to a point near the right side where the water layer is still clear.




Watching Bacteria Grow: Winogradsky Panel Day 4

The Winogradsky panel is developing much more quickly than I had expected. Differences are noticeable from day to day.

The panel at day 4.

The colors at the interface are richer and thicker. The green sulfur bacteria below the orange layer are more obvious now.

IMG_5937The modified mud layer now has more black spots and there are now some bright green spots, probably green sulfur bacteria.  GSB are more tolerant of high H2S concentrations than the purple sulfur bacteria, so are growing well in the areas where the black spots tell us there is H2S.  Note the gas bubbles at the bottom center of the image.  The squiggly lines are actually paths left behind by the movement of small, red larvae of midge flies, called blood worms.  They made their way up to the top, and are now all apparently dead.  (And will be food for some bacteria).