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

Sunday, 20 November 2016

                        DIMITRA-IOLI SKOUROLIAKOU
WEEK: 4th
LEFT: control
RIGHT: warmth-exposed

From the 3rd to the  4th week, we observed some differences. Firstly, we can clearly see that in both columns the water is not as clear as it used to be, due to the bacteria and the nutrients from the sediment. Also, a notable difference is the growth of a brown film on the surface of the bottles. This structure is consisted of microorganisms attaching to surfaces and developing biofilms. A biofilm is an assemblage of  microbial cells that is irreversibly associated. Biofilm-associated cells can be differentiated from their suspended counterparts by the generation of an extracellular polymeric substance (EPS) matrix, reduced growth rates, and the up- and down- regulation of specific genes.  The plastic material of our bottles is a great environment for microorganisms to growth. (Donlan et al, 2002) It is also important to mention  that water system biofilm is highly complex, containing corrosion product, clay material and filamentous bacteria. As we can see in the pictures, the concentration of the biofilm in first column is greater from the second one, even though biofilms can grow in very low and high temperatures. Thus, we can assume that in the 2nd column, the rapid fluctuation of temperature affects the bacteria not only directly by limiting the growth of the no-resistant at high temperatures, bacteria, but also it affects them indirectly by the overheating of the plastic bottle, that excretes damaging chemicals. This fact, can reduce even more the growth rates of biofilm. Also, in both columns the sludge is darker from the previous week, due to the anoxic conditions. Finally, it is remarkable that after 4 weeks, we can still observe some Annelida even in the warmth exposed bottle. This fact indicates the toughness of some organisms on the ecosystem of Lake Vrellis.

 In conclusion, the most noticeable difference from the 3rd week, is the growth of biofilms in both columns and the effect of rapid fluctuation of the temperature.

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

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