STUDENTS:NENA KOUKOUGELI
                        DIMITRA-IOLI SKOUROLIAKOU
UNIVERSITY OF IOANNINA GREECE
BIOLOGICAL APLICATIONS AND TECHNOLOGY
AQUATIC MICROORGANISMS

WEEK: 7th

LEFT: warmth-exposed

RIGHT: control

   Warmth – exposed column                                          Control column

  

  Between the 6^th and 7^th week, we couldn’t descry any obvious difference.

  The growth of the purple sulfur bacteria in the middle zone is still more visible in the control column than in the warmth-exposed column. During photosynthesis, unlike cyanobacteria or plants, they bind sulfur from the bottom of the column producing hydrogen sulfide, rather than oxygen. Thus, the purple sulfur bacteria cause anoxic conditions in the middle zone they grow.

  In both columns, is still observed the presence of biofilms, the concentration of which, is greater in the first column.

  This gradual distinction in the zones of the column, starting with the display of sulphates purple bacteria, has only been observed in the control column, even after 7 weeks. Thus, it can be assumed that the growth rate of the bacteria in the 2^nd column, is considerably slower, as zoning hasn’t been observed yet. This fact is probably due to the rapid fluctuation of temperature. In the warmth-exposed column, this affects the bacteria directly by limiting the growth of the non-resistant ones at high temperatures. Also, the bacteria in this column, in order to get protected from the temperature fluctuation, could form spores, which means a static metabolic condition. Rather than that, the overheating of the plastic bottle can excrete damaging chemicals for the bacteria.
  

Hypothesis: The rapid fluctuation of the temperature on daily basis, reduces the growth rate of the microorganisms in the 2^nd Winogradsky column

UNIVERSITY OF IOANNINA GREECE
BIOLOGICAL APLICATIONS AND TECHNOLOGY

AQUATIC MICROORGANISMS 

Team 7: Serasidis Konstantinos, Tsinoglou Makrina
Week: 4

Fourth week’s observation: 18/11/2016

Between the previous weeks and this week’s observations several changes have been noticed in the Control column. Firstly, at the bottom of the column green color has been noticed. Specifically, these changes state the growth of green sulfur bacteria. These bacteria require anaerobic conditions, sulfide ions and light effect in order to photosynthesize. Also, at the bottom of the column are noticeable black spots that are caused by anaerobic sulfur-reducing bacteria. These bacteria use either sulfate or oxidized forms of sulfur as the terminal electron acceptor, generating large amounts of H₂S. The H₂S will react with any iron in the sediment, producing black ferrous sulfide. At a higher level of the column a brown color in the sediment shows the growth of heterotrophic bacteria. There is a green color band immediately above the sediment. The green colored band is caused by the diffusion of H₂S from the sediment into the water column that enables anaerobic photosynthetic bacteria to grow. The orange color in the water of the column that is caused of purple non-sulfur bacteria seems to be the same as the previous week. Finally, biofilm is observed at the top of the water column. A biofilm is any group of microorganisms in which cells stick to each other and often these cells adhere to a surface.

At the bottom of the column in the dark, the sediment is observed darker in comparison with the previous week. The darker color of the sediment indicates the increasing growth of anaerobic bacteria. Also, black spots are noticed at the lower levels of the sediment that are caused by anaerobic sulfur-reducing bacteria. Additionally, the black band which formed at the upper levels of the sediment is caused by the growth anaerobic sulfur-reducing bacteria. The anaerobic conditions are formed by the diffusion of H₂S from the sediment into the water column. Finally, biofilm is observed at the top of the water column.

2.Column in the dark 

1. Control column    

STUDENTS:NENA KOUKOUGELI
                        DIMITRA-IOLI SKOUROLIAKOU
UNIVERSITY OF IOANNINA GREECE
BIOLOGICAL APLICATIONS AND TECHNOLOGY
AQUATIC MICROORGANISMS

WEEK: 6th

LEFT: control

RIGHT: warmth-exposed

The differences between the two columns are more obvious from the 5th to the 6th week.

In the first column, growth of urple sulfur bacteria in the middle zone is more odvious.

Purple sulfur bacteria are group of proteobacteria capable of photosynthesis and they are illuminated in anoxic zones. Unlike cyanobacteria or plants they do not use water as ther reducing agent, so they do not produce oxygen. Instead, they use hydrogen sulfide from the botom of the bottle which oxidised ti produse granule of elemental sulfure

In both columns, is still observed the presence of biofilms, the concentration of which, is greater in the first column

After 6 weeks, it has started a gradual distinction in the zones of the column, starting with the disply of sulphates purple bacteria. Considering that the forementioned zoning hasn't been yet observed in the 2nd column we can safely assume that it's groth rate is considerably slower. This happens probably due to the rapid fluctuation of temperature that affects the bacteria, not only directly by limiting the growth of the non-resistant, at high temperatures, bacteria, but also it affects them indirectly by the overheating of the plastic bottle that excretes damaging chamicals.

Hypothesis: The rapid fluctuation of the temperature on daily basis, reduces the growth rate of the microorganisms in the 2^nd Winogradsky column

Methane Production - Test with Fire

University of Ioannina

Team A (Gregoris Notarides & Kostas Karanicolas)