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