Winogradsky column lab page!

Welcome to the Winogradsky column lab page! Students from the Departments of Biological Applications and Technology, University of Ioannina and Icthyology and Aquatic Environment, University of Thessaly, Greece and the Microbiology course, Faculty of Sciences, University of Cádiz, Spain, discuss their findings on Winogradsky columns they constructed!

If you want to add a post, please feel free to contact the blog administrators (Hera Karayanni, Sokratis Papaspyrou or Kostas Kormas)!

Καλωσορίσατε στη σελίδα των Winobloggers! Διαδικτυακός τόπος συνάντησης φοιτητών, φοιτητριών και διδασκόντων δύο Τμημάτων από την Ελλάδα: Tμήμα Βιολογικών Εφαρμογών και Τεχνολογιών, Παν/μιο Ιωαννίνων και Τμήμα Γεωπονίας, Ιχθυολογίας και Υδάτινου Περιβάλλοντος, Παν/μιο Θεσσαλίας και ενός από την Ισπανία: Σχολή Θετικών Επιστημών, Πανεπιστήμιο του Cadiz. Παρακολουθούμε, σχολιάζουμε, ρωτάμε, απαντάμε σχετικά με τα πειράματά μας, τις στήλες Winogradsky!

Bienvenidos a la pagina web de los Winobloggers! Aquí los estudiantes y profesores de dos departamentos griegos, el Departamento de Aplicaciones y Tecnologías Biológicas de la Universidad de Ioannina y el Departmento de Agricultura, Ictiología y Sistemas Acuáticos de la Universidad de Thessalia, junto con los estudiantes de Microbiología de la Facultad de Ciencias en la Universidad de Cádiz, se reúnen para observar, comentar, preguntar y responder a preguntas relacionadas con nuestro experimento, la columna Winogradsky.

Winogradksy columns

Winogradksy columns
'In the field of observation, chance only favors the prepared mind' Pasteur 1854

Blog posts

Thursday, 10 May 2018

UCA_5B, 6B_1: Day 44

44 days have passed since we last checked our Winogradsky columns. In the column without sugar we can observe that some black sediments have appeared. That indicates the presence of anaerobic microorganisms (as sulfate-reducing bacteria) which produce H2S from CaSO4 (that served its purpose as a sulfur source). This compound finally reacts with the iron present in the sediment of Rio San Pedro, producing FeS, known for its black color. What's more, there's still some water remaining in this column. 

As the columns were placed in the dark we can’t notice the presence of photosynthetic microorganisms in neither of them.

​On the other hand, in the column with sugar we observe that the same anaerobic microorganisms that appeared in the column without sugar have appeared in this one too. 

Furthermore, we can see that some type of fermentation has happened (due to the fact that the water we found in the previous column has been pushed out, likely because of an excessive emission of gasses, such as CO2
), and we could in theory be able to determine its kind. In order to distinguish between lactic and alcoholic fermentation, we should have conducted some analytical experiments that we couldn't afford to do. Despite not knowing exactly what kind of fermentation it was, we can definitely confirm our hypothesis: if there are yeasts in Rio San Pedro (which has been proven to be right), in presence of sugar they'll undergo fermentative processes. 

Thus, we can conclude the experiment was successful and our hypothesis was accurate too.

We've already tested and confirmed our initial hypothesis, so for now on the columns will be placed in the light for further observations. We expect to find some photosynthetic microorganisms that may (or may not) benefit from the increased growth rate found in the column where we placed 4 g of sugar (no more, no less). Considering the enormous emissions of CO2 (coming from either fermentation or cellular respiration) in the sugar column, we believe this could help photosynthetic microorganisms proliferate, which capture and reduce CO2 in order to grow, as shown in the following animation.

Hence, we estimate a greater growth rate of photosynthetic organisms in the sugar column, compared to the control one (that has no sugar at all).

1 comment:

  1. The sulfate of CaSO4 is primarily an electron acceptor for sulfate reducing bacteria.
    Fermentation is not only performed by yeasts. Bacteria also ferment (as you do too in your muscles...).