Winogradsky’s Column

UNIVERSITY OF IOANNINA GREECE
BIOLOGICAL APLICATIONS AND TECHNOLOGY

AQUATIC MICROORGANISMS 

Team 7: Serasidis Konstantinos, Tsinoglou Makrina

Weeks: 5-7

During these three weeks there weren't observed any significant differences between the columns. However, between these weeks and the 4^th week a main difference has been noticed in the Control column. The color of the water in the column appears to have green- brown color. In contrary with the 4^th week the water had bright orange color. This difference is probably caused by the growth of cyanobacteria. Cyanoabcteria have oxygen-evolving photosynthesis like that of plants. Once the cyanobacteria start to grow they can oxygenate most of the water. So, the conditions in the water became aerobic and the purple non sulfur bacteria that need anaerobic conditions and are responsible for the orange color can’t grow anymore. That’s why the color in the water turned from orange to green after a few weeks.

The 7^th week is the last week of Winogradsky’s columns growth. The experiment ended successfully and our hypothesis was confirmed. Our hypothesis was that in conditions that light is absence the growth of phototrophic bacteria will be absence too. The results have showed that clearly, as green and orange color that indicates the growth of phototrophic bacteria was present in the Control column and absence in column in the dark.

2.Column in the dark 

1. Control column