University of Thessaly, Group number:19, Day number:39, Incubation:Light

  Our names are Vasiliki Papadimitriou and Nikos Danavaras and we are presenting our results from Winogradsky column experiment, from day 12 to day 39.

01/04/2016

  In the twelfth day the water is turbid and its colour has become green. The water level is in the same level as it was the previous days and we can also see the thick white line in the middle of our bottle. The sediment continious becoming darker and this is the first day our experiment presents an intense odour.

03/04/2016

03/04/2016

  In the fourteenth day our bottle has pretty much the same occurance except from the water level which is higher and has reached the surface of the bottle. We can also see that the surface layer is thicker.

04/04/2016

04/04/2016

  In the fifteenth day the water level is much lower compared with the previous day and we can see that the white line in the middle of our bottle has disappeared. We can also observe that the protective film in the surface of our bottle has pulled inwards.

06/04/2016

  In the seventeeth day we can see that various residues in the top of our bottle have disappeared and that the water is less turbid and its colour is no longer green.

11/04/2016

  In the twenty second day the water is more turbid and its colour has become green and light purple.

13/04/2016

  In the twenty foutrth day the only difference we can observe is the water colour which has become purple and is explained by the presence of photosynthetic microorganisms.

16/04/2016

16/04/2016

  In the twenty seventh day the water colour is darker purple and the water level is higher compared with the previous days. We can also see that the protective film in the surface of our bottle has pulled inwards, so much, that the shape of our bottle has changed.

21/04/2016

  In the thirty second day the water colour is still purple but in the middle of the bottle, the water is darker and more turbid than in the top of the bottle.

28/04/2016

  Today (39th day) we can see that the water is very turbid and its colour has become dark pink. We can also see that our sediment has started becoming purple, like the water was the previous days.

Univ. of Thessaly, Group number 36 (Christomanos - Yfantis), Day 0-35, Incubation: Dark

Univ. of Thessaly
Group number 36 (Christomanos - Yfantis)
Day 0-35, Incubation: Light

The experiment started on 21/3/16 at Anauros beach. The protocol that we followed is shown below:

1) We took the sediment from the bottom of the sea and mixed it with a few pieces of newspaper and a broken egg with its shell.

2) We filled the 2/3 of a plastic bottle with the mixed sediment and filled the rest with sea water.

3) We covered the column with a trasnparent film and placed it behind a sunny window.

The first day the sediment had a light brown color and the water was light yellow (because of the broken egg).

As the days passed, the color of the sediment began to darken until it became black. On the contrary the water became lighter and after a period of 20 days it turned into purple red as a result of the photosynthetic microorganisms. At the same time the scent of the sample went from bad to worse.

Day 1

day 7

Day 14

day 21

Day 28

Day35

3.-UCA_10B_1: Day 28

Sediments from the San Pedro river + 1g CaSO4

After two weeks, on the illuminated side (Photo 3) we can be observed green filaments and small pockets of air, which may correspond to photosynthetic microorganisms that produce O2 (air bubbles). On the other part where there is no light (Photo 4) we continue observing larger and larger black spots (developing colonies, which are caused by microorganisms that use sulfate as an electron acceptor and transform it into hydrogen sulfide, which reacts with iron causing black iron sulfide (II). The orange color also corresponds to an iron compound, but this time it is iron oxide.

It should be added that there is a small plague of snails on the surface of the column, at the boundary between the water phase and the solid one. On the no illuminated column (Photo 5 and 6) there are many more black spots corresponding to the hydrogen sulfide mentioned above. On the surface, however, there is a kind of reddish fuzz which could be iron oxide.

2.-UCA_10B_1: Day 14

Sediments from the San Pedro river + 1g CaSO4

After two weeks two distinct phases of water and sediment can be seen. In the light face (Photo 1) there is no development of colonies at the first sight , while in the no light face (Photo 2), we can see different types of colonies with different sizes, punctate and black color. At this face it is also possible to see an orange delimitation separating the illuminated face from the dark one. Sediments are greyish on the part that does not receive light and brown on the other. In the water phase numerous fine filaments have developed. When we compared it with the bottle that is in the dark, we realized that this also presents two distinct phases, but water is much murkier than the other. The sand is greyish and it presents many more colonies. It is also possible to observe orange tones as in the case of the bottle exposed to light, but this time is on the sediment surface.

1.-UCA_10B_1: Day 0

Sediments from the San Pedro river + 1g CaSO₄

We mixed sediments with some water (looking like a milkshake) and added one gram of calcium sulfate using a funnel to fill 1/4 of the content. Then we added sediments from The San Pedro river to fill almost the whole. Finally we added some water. At time zero, the bottle has a uniform color (dark brown) and the same in all content. Then we placed on a lit place in order to create an ecosystem with a gradient of O2 which decreases down and one of sulfate which decreases upwards.

UCA_1B_3: Days 35,42

Our column remains the same since the last day we checked it. Anyway the water level has risen even more.

University of Cadiz_11B-1B_1: Day 1- The beginning of a glorious empire

Hi everyone!! We are a group of two biotechnology´s students from Cadiz University. We did the Winogradsky column experience two months ago and now we are making public our results. To prepare the column, we just added sediments from Rio San Pedro and mixed it with sea water in a plastic bottle of 1,5L.  Afterwards we exposed our Winogradsky column to sunlight.

We made the Winogradsky column on 23/02/2016. Two weeks later we took the first three pictures.

08/03/2016     (Indirect sunlight exposition) it has appeared orange patches and small black spots.

                       (Direct sunlight exposition) This part has become lighter and now it has a light brown color.

                               

           

            Direct sunlight exposition                       Indirect sunlight exposition                      Half and half

15/03/2016      (Indirect sunlight exposition)  We’ve noticed an important increase of orange patches                            and a descent in the number of black spots.

                         (Direct sunlight exposition) No significant changes.

                             
    

                    Indirect sunlight exposition            Direct sunlight exposition                      Half and half

4/04/2016       (Indirect sunlight exposition) Orange patches have increased even more, we nearly                               can’t appreciate black spots.

                        (Direct sunlight exposition) No significant changes

                        On the surface of the Winogradsky column some algae have grown.

                              

                           Indirect sunlight exposition                   Half and half                           Direct sunlight exposition

Justification

We think that orange patches are rusty iron produced by iron oxidizing bacteria’s metabolism. (Fe²⁺ -->Fe³⁺)

Black spots might be iron sulfides, which could have been made by the combination of rusty iron that we’ve mentioned before and sulfur produced by non-sulfur bacteria.

Algae have grown thanks to the sunlight and the carbon dioxide produced by heterotrophic bacteria, located on the direct sunlight part.

See you soon

To be continued...

UCA_1B_2: Day 14: Orange is the new black.

Rio San Pedro sediment.

After two weeks in darkness some black spots have appeared in the whole column, specially at the bottom of it, while on the top a orange layer has arisen. Water level has risen because the soil has settled more than the last day we checked it.

  

The black spots are FeS, formed by the reacction of H2S (product of the anaerobic respiration of microorganisms) with the iron in the sediment.
The orange layer correspond to FeO, result of the reaction of the iron form the sediment with the oxigen in air.
This arrangement of the different components is due to the fact that as we go deeper in the column, the quantity of oxigen decreases and the sulfur one increases.

UCA_6B_2: Day 14 - The Return of The Column

Rio San Pedro sediment + 1g CaSO4


Our column has return from the dark side (the box) and we can see some changes. The whole column has little dark stains between the sediment and we could recognize them as reduced Iron.

The bottle with the FeS (black stains)

This is a result of two situations: the first one is the change of the pH (which is more acid) and the other and more important one is that some microorganisms obtains energy oxidizing the Iron like, for example the Thiobacillus ferroxidans, so the dark stains we can see are the FeS created by the microorganisms that reduce the Iron.

The water is dimer due to the increase of the organic matter (due to the eutrophication). Compared to the others columns ours is darker because of the high proliferation of the microorganisms, who will reduce the Iron. The high proliferation is helped by the CaSO4 which is use by the chemosyntethic microorganisms as nutrients in the trophic chain.

We add some photos to see what we describe in the post: 

The top of the column.

University of Thessaly

Group Number 32

Incubation Dark

Minimal changes where observed from Day 10-23. The cloudy white substance above the sediment mostly likely due to sulphur oxidising bacteria in an aerobic environment started dissolving through day 15-23 resulting in a white liquid above the sediment. No changes observed in the sediment.

                                                                                    DAY 15

 

                                                                               DAY 20

                                                                                DAY 23

Say hi to our green friend.

UCA_1A-9ª_1: Day 35. 

In the dark column there hasn’t been any great changes. Dark zones are similar as last week but more expanded. It means that sulfate-reducing bacterias keep growing!

This week there is something new in our light column. Some green marks have appeard where sunlight falls! Plus, we have noticed there are less sediment and water than last week. It is possible those green zones are because of phototroph microalgae which use water and CO₂ (produced by aerobic microorganisms) to produce their own sugar and oxygen.

Next week we’ll see if there are more new changes in our columns. See you soon mates!

Light column

Dark column