Winogradsky column lab page!


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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!

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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, 17 January 2019

How does a blue transparent bottle affect the growth of micro-organisms?

Hi everyone,

This is my final report about my Winogradsky Columns.


Materials


  1. Transparent plastic bottle (1.5 L)
  2. Mud from Lake Pamvotis (2/3 of the bottle)
  3. Water from Lake Pamvotis (1/3 of the bottle)
  4. Carbon source (5 g newspaper in small pieces )
  5. Source of sulfur (1 whole boiled egg 70g)
Hypothesis



Since bottle (2) contained 1/3 of the nutritions compared to bottle (1), it would have a slower growth rate (of the organisms it contained) as its metabolic processes would be slowed down .


Bottle (1)                                                     Bottle(2) 
After 60 days 

Summary of Results




The experimental hypothesis was not confirmed as bottle (2) with limited enrichment materials contained greater abundance of microorganisms than bottle (1) with evenly distributed enrichment materials throughout.
It is possible that the color of bottle (1) (transparent blue) affected the light that penetrated it and thus the growth of photosynthetic organisms.
In fact, visible light consists of wavelengths of 400-700 nm. Blue light corresponds to wavelength (λ)= 450 nm, and therefore this λ could not be absorbed by the micro-organisms as it is reflected by the bottle.
In the diagram below you can see the absorption spectra of three basic dyes in photosynthesis:chlorophyll a, chlorophyll b, β-carotene.
All three pigments show a peak for λ ~ 450 nm

Source: khanacademy.org

In particular, all micro-organisms that could be cultured in Winogradsky colums show a peak in their absorption of wavelength λ ~ 450 nm through their pigments.
Source:
Colorful niches of phototrophic microorganisms shaped by vibrations of the water molecule
The ISME Journal 1 p.271-282 (2007) - M. Stomp et. al.
volum1pageM. Stomp et. 
Especially, purple sulfur bacteria,acorrding to a study (Photosynthetic development of purple sulfur bacteria during illumination with green light-Osnitskaia LKChudina VI-1977),use short wavelengths of natural light, blue and green, for CO2 assimilation and biosynthesis of biomass, proteins, and pigments.

Which means that the photosynthetic ability of the micro-organisms in bottle (1) was lowered because their pigments didn't absorb wavelength λ ~ 450 nm. That way, the growth of photosynthetic organisms in bottle (1) was slowed down and in the course of the same time showed lower abundance of micro-organisms than bottle (2).

Christina Diamantopoulou
Department of Biological Applications and Technologies
University of Ioannina-January 2019


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