Mystery Microbes of the Sea

Anna Kramer

Author: Douglas Fox
Date: September 26, 2013
Link: https://student.societyforscience.org/article/mystery-microbes-sea?mode=topic&context=79

Summary
A biologist named Alyson Santoro may have discovered the reason to why the large amounts of waste do not turn the ocean into a giant pool of sewage, poisoned with ammonia. Also, the same organisms eating the ammonia must be releasing the nitrous oxide greenhouse gas into the air. Santoro collected samples of seawater in four water bottles and left them in her fridge, forgetting them for two years. Scientists had not been able to grow enough of these microbes to study them, but by leaving the samples in her fridge, Santoro allowed the slow-growing microbes to thrive while the fast-growing microbes which usually outnumber the other microbes died off. Once her sample had a large enough population of the more unique slow-growing microbes, they were able to study it. They realized that it was archaea that was eating the ammonia, not bacteria. Yes, bacteria in the ocean do eat ammonia and release nitrous oxide gas, but the gas did not have the same composition as the nitrous gas released from the ocean. The archaea produced nitrous oxide gas that was much more similar. They hypothesis that these microbes, archaea, that we do not know as much about as bacteria or eukaryotes, are keeping the oceans cleaner. Learning more about this could lead to future predictions about global warming because as more human waste containing ammonia leaks into the oceans, the microbes consume the higher quantities and as a result are releasing more of the nitrous oxide greenhouse gas.

Connection
This connects to our unit on microbes. The whole article is based on the process that these forms of archaea perform in order to keep the oceans clean from the large amounts of ammonia. The article mentions a lot about how archaea were before mostly found in extreme environments, that's why this discovery of archaea in a milder environment like the ocean is appreciated. The similarities that bacteria have to archaea is something else we studied. They talk about how archaea, although seemingly similar to bacteria, are no more related to bacteria as an elephant is to an apple tree. Another topic we studied was the nitrogen cycle, and the story bases a lot on the circling of the ammonia to nitrous oxide gas.