As we have previously mentioned, we obtained our Winogradsky columns from last semester’s class. We initially met with Professor Chet Fornari and decided that it would be interesting to switch the columns from last semester’s setup. We placed the previously lit column on the opposite side of our lab bench and replaced it with the previously non-lit column. This newly lit column was set directly next to a 75 watt bulb in order to receive constant light. This experiment involved changing a single variable of our Winogradsky column, this variable being a source of light.

We began with some simple observations starting March 5^th and obtained multiple copies of Winogradsky Column data sheets in lab. These became very crucial and beneficial as they were used to sketch out basic growth patterns and colony blooms within each column. We performed these observations weekly until May 7^th, allowing us a visual aid to our documentation of our columns succession. In addition, we each kept updated journals in which we verbally explained growth changes and any observations pertaining to the succession of our column. Between our journals and data sheets we were able to keep an accurate account of our columns over the two month period.

On March 7^th, we met in lab and added our nutrients and chemicals to promote the growth of microbes within each of our columns. To each was added approximately 4.00 grams of Calcium Sulfate, 4.00 grams of Calcium Carbonate, and 1.00 gram of Sodium Sulfide to ensure equal amounts of nutrients in each column. We mixed the chemicals with separate sterile glass pipettes to ensure even distribution of the chemicals with in our columns and to prevent any outside contamination. Our final act on this first weekend was the placement of a plastic bag over the top of each column and securing it with a rubber band to retard evaporation or accidental contamination.

We returned to lab on March 12^th, only five days after adding the chemicals to notice extreme changes within our column, which we documented on our Winogradsky column data sheets and added to our journals. We also documented a pungent odor of rotting eggs in both columns, attributed to the addition of chemicals the previous weekend. At this time we began our initial observations on both column’s pH and temperature. We made it a point to try and measure the pH and temperature twice each week throughout the duration of our observational period and experiment and record them onto our data sheets along with our weekly observations.

Prior to spring break, on March 14^th, our laboratory group felt ambitious and decided to plate organisms from single slides left in each column from last semester’s class. The slides were located directly on the mud surface in each column and time and skill was required for the tedious task of lassoing the slides with fishing line strung through a sterile pipette. After they were finally extracted, we worked quickly to plate each slide onto three successive TSA plates which we kept separate and labeled with their order and from whichever column they were extracted. Within two days of growth in the incubation closet, we were streaking plates for isolated colonies. By the beginning of spring break, March 20^th, we believed we had successfully isolated two colonies which we unfortunately placed back into the incubation closet set to 37 degrees Celsius.

After our return to campus, we returned to lab to find our potential isolates dead and desiccated. After conferring with the lab assistant, we agreed to remove the slides left from the previous semester’s class. We then added our own slides during our laboratory period on April 2^nd. Adding three slides to each column, we secured fishing line around each of them with black electrical tape to prevent having to lasso them and also to make slide extraction much easier. This procedure also helped us secure slides at multiple levels throughout the column. In each column, a slide was placed at three distinct levels, with one placed directly on the surface of the mud, another near the water surface at the top of the column, and a third half way between the two, in the water portion of the column. We felt that hanging slides at these three levels would allow us to collect organisms from a wide variety of environments within each column.

In the next week, our laboratory group was back in the microbiology lab plating different slides just as we had done previous to spring break. After allowing a few days for growth, we were able to start repeatedly plating microbial growth. We later continued by streaking different plates in an attempt to isolate colonies. By mid-April, we each had at least one isolate, often more, which we began to test. Each of us began by Gram staining our isolated bacteria, which we all performed twice to confirm our results. It was interesting and fun, because we each helped each other out in the process of determining our results throughout the duration of the identification process.

Once we obtained our Gram stain results and cell morphology, we consulted the Bergey’s Manual flow charts located in the back of our Customized Microbiology Laboratory Manual. We located our individual flow charts and each began to test our unknown isolates. Although we took an individual approach to the testing of each group members unknown, we found it very helpful and interesting to consult as a group and discuss our own findings. Through these informational meetings, we were able to learn much about our own isolates, as well as each others.