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

Wednesday, 6 April 2016

UCA_1A-9A_1: Day 14 Darker in the dark

Rio San Pedro sediment + 1'48g CaSO4+ filter paper

First of all, I’ll explain how we made our Winogradsky column two weeks ago. We took some sediment from Rio San Pedro and removed all the shells, wood sticks and rubbish that we found. After that, we added 1.48g of CaSO4, some filter paper which it’s rich in cellulose, and some water from the same place as the sediment. Then, we mixed all and filled ¾ parts of the bottle with it. Finally, we filled half of the remaining part of the bottle with water. Later, we made two columns. The first one has been exposed to the sunlight and the second one has been in a closed box.

Some components have separated due to their density, which means that most of the CaSO4 has moved to the bottom of the column while on the top there is a lot of oxygen. Therefore, we expect aerobic microorganisms to grow on the top of the column while anaerobic microorganisms will grow at its bottom. Dark column should contain chemotroph organisms because it has not been exposed to the sunlight, whereas light column might contain chemotroph as well as phototroph organisms.

Dark column:

We can appreciate some dark zones spread around the bottom of the column where there is less oxygen and more CaSO4. This effect occurs because sulfate-reducing bacterias reduce sulfate (SO42- ) to hydrogen sulfide (H2S) which reacts with the iron contained in the sediment and so producing iron sulfide (FeS) which is black.

Light column:

In this column there are more dark zones than in the dark one, which means that there are sulfate-reducing bacterias. They are found at the bottom of the column as well. However, in this case there are red marks all over the column because the Fe3+  is produced by iron-reducing bacterias.

Comparing both columns we found out that there is more Fe3+  where sunlight falls. This is why we see more red marks on the left side of the light column (pic. 3). To conclude, iron-reducing bacterias are phototroph, and sulfate-reducing bacterias are both chemotroph and anaerobic because they accumulate at the bottom of the column. However, both bacterias use carbon from filter paper.

Light column

Dark column

Pic. 3


  1. Excellent observations !!!

  2. Just one comment/correction. Iron reducing bacteria respire organic mater by reducing Fe(III) (solid oxides) to Fe2+ (soluble ion). Iron oxidising bacteria work the other way around, they oxidise Fe2+ to Fe(III) and fix CO2.

    Keep observing!