Ecology Continues

January 28, 2011
We’re up to our eyeballs in mold and decomposition in Ecology class. Currently we are monitoring 3 different experiments. In the second week of class we started a compost column with various produce, some potting soil and compost enhancers. The column is constructed out of 2 plastic soda bottles. 2 weeks later, the materials inside the column are covered with green and white mold and no longer recognizable. Thankfully the set up of the column allows for any liquid produced by the decomposition to be drained into a bottom portion of the column. We’ve been checking this brown liquid for nitrate and nitrite levels. This is by far the most aromatic of our experiments. Another experiment we are watching is the growth of mold on petri dishes with jello acting as a culture. There is nothing growing on my control but white spidery mold covers the petri dishes with soil samples on top of the jello culture. Our third experiment involves the growth of mold on pieces of bread. Each of us was asked to conduct this experiment changing 1 variable. I chose to look at whether or not a change in pH would have any effect on the growth of mold. I exposed my preservative-free slices of bread to the air in my kitchen overnight. Afterwards I dipped 1 side of each slice in one of the following: milk, vinegar, lemon juice ammonia, honey, baking soda. The lemon juice and vinegar have higher levels of acidity while the ammonia has a higher alkalinity level. Both the milk and baking soda are more neutral in pH. One piece, my control was dipped in nothing. I decided to include honey in the experiment because it is known as a natural preservative.17 days later the only bread with mold (36 cm) on top is the milk piece. No surprise there but is it the milk that is molding or the bread? Hard to tell. There is 39cm of growth on the bottom of the baking soda piece and 33cm on the bottom of the milk piece. It appears that these 2 two are promoters of mold. Surprisingly to me there is no mold on any part of any of the other pieces. It appears that substances with a neutral pH are better promoters of mold growth. I’m eager to see which slice will begin to sprout mold next. I don’t think they can resist it forever… or can they?