2/16/15
Our adventure began on the small, yet highly potential campus of Birmingham-Southern College. The goal of this extensive experiment was to have a better understanding of all the microbial organisms that lie right beneath our feet. We first chose a prospective area of where we would gather our soil samples from. Our particular area of study lays in front of the Stockholm Women's Building in a small opening between shrubs in the surrounding landscape. We noticed here that plant growth within a ten yard radius of our specific sample of dirt consisted of only shrubs. The building lays about fifteen yards from our location. Our soil sample consisted of dark brown dirt that contained tiny increments of shrub roots and pebbles. It was rather soft and mildly compact with an average amount of moisture.
In order to investigate our site's microbial activity we gathered a small sample of dirt using proper aseptic technique to avoid contamination. To prepare our sample we weighed out a small portion of dirt and mixed it with sterile water thoroughly.
Next, we allowed the particulate matter in the soil to sink to the bottom and pipetted 1ml of this solution into a microfuge tube. From this 1ml sample we prepared five different dilutions. Each dilution contained smaller concentrations of soil extract. Furthermore, we placed 100 ml of soil extract from each dilution into five labeled TSA plates and spread them appropriately. In addition, we placed 100 ml of the 10-4 dilution onto a Rose-Bengal Plate which allows for selective growing of different fungi from or soil sample. After six days we observed our TSA plates for microbial growth and found that nearly all of them contained growth except for our 10-7 dilution plate. With each smaller dilution, we found that the number and size of colonies decreased. We also found that our Rose Bengal plate contained a large amount of fungal growth.
