Fall 2017: From Colby to Cable Bacteria

Meg Yoder
This is a confocal microscope, one of the instruments I’m using in my research.

Does sulfur sound like a nice snack to you? Ever had the urge to munch on some iron? I haven’t, but I’ve recently begun learning about bacteria who do. This semester I’ve been working in the Emerson Lab under the guidance of David Emerson and his post doc, Jake Beam. The research in this lab focuses on iron oxidizing bacteria. These bacteria use iron as their energy source, much in the way you and I use food. By studying these bacteria, they aim to understand the role they play in iron cycling, the implications this may have for finding life on other planets, and their potential practical applications, such as reducing groundwater contamination.

I’m a Geology major with a minor in environmental studies, and while I’d heard of metal oxidizing bacteria before, that was pretty much the extent of my geomicrobiological knowledge. Upon arriving at Bigelow, I sat down with David to discuss the independent project I’d be working on for the semester. We landed on investigating sulfur oxidizing cable bacteria as a topic, and before I knew it I was diving right into the research. Jake or David will explain a procedure and then, after seeing it demonstrated, I’ll get the opportunity to try it out myself.

The sulfur oxidizing cable bacteria I’m studying live in marine sediments and feed on hydrogen sulfide. In order to investigate these organisms and their effects on the sediments, we take sediment samples from mud flats near the lab and look at the bacteria under the microscope. We’re also doing geochemical analyses of the sediments, identifying the different amounts of things like sulfur and iron and seeing how they correspond to the presence of the cable bacteria.

One of the most interesting parts of conducting research at Bigelow is how different it is from the lab work I’ve done for my courses at Colby. In those labs, we may not know the actual result before conducting the experiment, but the lab instructor does, and the procedure has been created for us so that we can focus on learning the techniques and analyzing the data. Working in the lab at Bigelow has shown me how different conducting scientific research can be from that meticulous classroom process. So far, a big part of the work that I’ve been doing is actually figuring out how to get the information that I’m looking for. Cable bacteria are a relatively newly discovered species and are not well studied, particularly in the context of worm burrows. This means we’re the ones figuring out the best methods for imaging the cells. It’s really cool to be faced with a challenge and know that there is no known solution yet. I’ve enjoyed my time in the lab so far and am excited to see what else I’ll be working on.

Meg Yoder is a Colby College student in Bigelow Laboratory for Ocean Science’s semester-in-residence program. This intensive research experience is focused on ocean science within a changing global climate.

Fall 2017: From Colby to Cable Bacteria