UCA_8&4B_3- 8th Week: The column... my treasure

After eight weeks, some changes are noticeable.

Dark Column: Probably column changes are not too remarkable this time, they could be group as a colour darkening. It could be due to an increase bacteria concentration. Top layer is unchanged.

Here, we include an explanation of why dark colour is produced:

Dark area growth indicates the presence of two types of bacteria. Desulfovibrio and Clostridium.

Desulfovibrio genus bacteria uses both by-products of the fermentation carried out by genus Clostridium anaerobic respiration and sulphate salts added in the sediment, generating large amounts of H₂S in the process. This H₂S reacts with iron present in the sediment, producing ferrous sulphide which justifies the black colour.

As said before, dull area progressively expands. This is caused due to Clostridium strictly anaerobic condition (it will die in presence of oxygen). As oxygen which is still contained in the sediment disappears, population will be more spread, producing more metabolites (ethanol and organic acids). This contributes with the increase of Desulfovibrio population thus producing more SH₂ and iron sulphide, obscuring that area of the column.

Clostridium bacteria metabolize the cellulose which comes from paper in order to produce glucose. Afterwards, by fermentation, energy will be gained, obtaining these metabolites in the process. 

Light column: Water has become orange, mollusk died and bateria dominate the column. In the light zone many bacteria have grown while in the dark zone there is nothing. We can see all around the bottle a very intense orange due to iron oxide. In the bottom we see again the sulfate-bacteria that produce the dark colour and we can also see violet spots that tell us there are sulfure-bacteria.

UCA_A4_1: Day 42

Rio San Pedro’s sediment + 30g NaCl + 1.5g CaSO₄ + Piece of paper

6th of April. After 6 weeks since column preparation, we could see them for third time. This time, we didn´t see obvious changes like another ones. It should be pointed out an increase of respiration products of microorganisms, as in the light column with iron oxide (orange) and iron sulphate (black), as in the dark column which prevails only iron sulphate. We can also emphasize an increase of microorganisms on the surface, where are mainly green algae.

UniversidadDeCádiz_GrupoB4B7_Entry4: Day 42

Hi everyone! We have observed both colums after other two weeks

The bottle that it has been kept by the dark has undergone few changes, only the level of the water has increased due to that the number of seaweed has increased too.

Also in the lit bottle the volume of water has increased, besides the water is murkier now, it is owing on to carbon dioxide. Green patch of cyanobacteria remains the same.

The same bottle, in the back where it has got no given it the light, behind the water it was returned darker because of reduced iron.

In addition, the sone of the iron colour has increased, it is due to oxidative iron bacterians.

The bottle ,which is at the left, is at the darkness. And the other bottle, which is at the right, is at the lit.

The  bottle  which is at the lit.                                                           The bottle which is at the darkness

We can see in the comparative photograph:

University of Thessaly
Group number: 20 (Papadopoulou Aikaterini-Papaioannou Evangelia-Anna)
Day number: 45
Incubation: Dark

 Winogradsky colum

Hello to everyone

·                     DAY 14 (4-4-16)

                                        Fig 1  

                                                      Fig 2

·                     DAY 17 (7-4-16):

                              Fig 3

·                     DAY 21 (11-4-16):

 
  Fig 4  

                                                                                                         
Fig 5

·                     DAY 24 (14-4-16):

Fig 6   

                                                                                                
  Fig 7

·                     DAY 28 (18-4-16):

                                

                                   fig 8                                                                  

fig 9

·                     DAY 31 (21-4-16):

fig10

fig 11

·                     DAY 35(25-4-16)

fig 12

fig 13                                                  

    On the 14th day of the experiment (Fig.1)we observed a change in the liquid phas eof the experiment in an intense beige color with white and black colors probably due to the start of the degradative activity of microorganisms and the presence of suspended particles. The precipitate has been tarnished almost entirely due to the iron and other reasons which we have mentioned in our previous post. While the odor has become unpleasant  because of hydrogen sulfide in the column. Also on the surface (Fig 2) growth of the foam was observed and existence of bubbles which may suggest the presence of intense microorganism action and oxygen trapped.

  

  On the 17th (Fig 3) of the experiment change a change was observed in the color of the liquid phase. A beige-brown color replaced the previous beige one, whilst the white foam along with the bubbles remain in the surface. Also the precipitate showed no significant change compared to the previous count while the upper column was a white layer probably due to calcium, which is present in large quantities in seawater.

  On day 21 of the experiment the only change observed  was in the water column surface (Figure 5) where the foam has taken the form of crust. This is probably a result  of the calcium carbonate which is contained in one of the enrichment materials used in this experiment (egg).
  

  On day 24 of the experiment  the precipitate seems to start losing its beige coloration in the water column (Fig 6) and the foam-bubble crust on the surface (Fig 7). This might be a result of  the death of the microorganisms present  resulting in the lack of oxygen.

On day 28 of the experiment seems  the beige color in the water column (Fig 8) becomes  even lighter for the aforementioned reasons . The same applies to the surface of the water column. It was also observed that the upper column of the white precipitate layer disappeared.
   

  On the 31st day of the experiment the reduction of  the foam-bubble crust (Fig.11) is more noticeable than the changing of the color of the water column, which does not appear to have any change compared to the previous measurement (Fig.10)

The 35th day of the experiment observed reappearance of foam-bubble crust (Fig.13) with small changes in the color of the water column (Fig.12)

Notably, the odor remains strong in all the above measurements.

UCA_GEN_5B-8B_3:Day3

Day 3

01/04/2016

We can differentiate according to previous observations, regarding the column exposed to light we can see that water has lost turbidity, possesses a layer surface bacteria like the previous observation. Only black color apppears at the bottom of the column, the side of the column that does not receive light directly it is darker, i.e. that it possesses more iron sulfide. Shades of Orange appear on both sides of the spine, presenting more orange tones by the part who receives the light directly. The upper part of the column presents hints in greater numbers to the side of the column that does not receive direct sunlight. There are air bubbles throughout the column, especially in the intermediate zone. Compared with the dark column, we can see that there is not any change.

UCA_GEN_5B-8B_2:Day2

Day 2

11/03/2016

Comparing two columns, we can see that after a week the column exposed to sunlight possesses a part of brown color lighter than the rest of the column since you have been exposed to direct light for that area of the column. The part against the light has an almost black color, due to the photosynthetic action of the microalgae. The ground has settled and the water is at the top with turbidity.

With regard to column not exposed to direct sunlight, the major changes that we see are the appearance of dark spots regarding the rest of the column.

UCA_GEN_5B-8B_1:Day1

Day 1

04/03/2016

Sediment San Pedro River, filter paper, 0.5g of calcium carbonate(CaCO3) and 2.0g of calcium sulfate (CaSe4) with salt water.

Mix everything together and then add two bottles one of them will be exposed to sunlight and the other in the dark to observe the different phenomena that occur.

UCA_A8Group_#Day49 Río San Pedro sediment (column in the dark)

Our column doesn't show any changes, this is because our bacteria are in the dark so the only product they can synthesize is FeS. On the other hand, our patners have their column in the light so it shows a lot of colours such as green, red and black, because their bacteria can synthesize more products than ours.



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UCA_GroupA2_Day 47_Rio San Pedro sediment + 1,5 g FeSO4 + paper_(column exposed to sunlight)

Forty-seven days have passed since we prepared the column, and there are important changes on it.

• We can appreciate that the red color has intensified throughout the entire column, but the top of it is more intense than de bottom. This is because more purple non-sulfur bacteria have grown.
• Moreover, the water is more turbid than the last time we see the column, which is a sign that there are more algae. 
•  There are also some green veins in the middle of the column, which indicates that green sulfur bacteria have grown there (like chlorobium).
• At the bottom of the column, we can see that the color is still the same, between black and grey. In this part there are cellulose fermenting microorganisms, because it is the anaerobia part of the column in which microorganisms can´t use the oxygen.
  
  
  
  

UCA_GroupA2_Day28_Río San Pedro sediment + 1.5 g FeSO4 + paper_(column exposed to light)

We noticed that some grey grains have appeared in the column and that the water is becaming turbier. It seems that new algae are growing too and that they are increasing their number.

On the other hand, we can notice that there are little spaces through the column. It seems like they were keeping bubbles. Possibly, they were made in the moment of the creation of the column and now they keep CO2 liberated by the bacteria around them, that is caught by the soil).

Looking carefullier, we notice that violet grains are being made (a new colony of bacteria?) in the middle of the column. The column is exposed to light, so they possibly do photosyntesis… there are black grains through the column too. Instead of the fact that they had already appeared in days before, now they are bigger and darker. It seems like the colony of bacteria that live there are growing or increasing their concentration.