10%

There is nothing that situates my thoughts concerning this course more than Ted Talks. I see Ted Talks as window into a world wherein the complex theories we delve into in class manifest into relatively applicable modern scientific studies. 

Last week, I came across a TedTalk given by Bonnie Bassler, a molecular biologist. Her piece, 'How Bacteria Talk', had my head reeling within the first few minutes as she declared "At best, you're only 10% human". What Bassler meant by this statement was that at any moment a human being has about 10 trillion bacterial cells in his or her body, about 10 times as many bacterial cells than human cells. The cells that I believe make me human, allow me to function as a human in our biosphere, cells that feed my cognition, are actually outnumbered by these foreign, distinctly non-human organisms. 

There is no cause for alarm, as the bacteria found in our bodies are not free-loaders. Through evolution, human beings have developed symbiotic relationships with bacteria that allow us to remain healthy, as bacteria aid in food digestion, the education of our immune system to recognize dangerous microbes, and even create vitamins. However, you cannot ignore that there are bacterium that wage war against the human body, such as STDs, cholera, malaria, and so on. One single bacterium can not totally inhibit the function of human beings; it is in a collective that damage is done.

Despite the collective power of a dangerous bacterium such as cholera, bacteria have always been considered too small to have an impact on any environment, and are generally regarded as asocial organisms. Our tendency to perceive bacteria this way is what sparked Bassler and her team to research whether or not there is a different way that bacteria co-exist. The curiosity of the team lead them to study a bacteria called Vibrio Fischeri, which generates bioluminescence through sociability. Bassler notes that, “When the bacteria were alone, so when they were in dilute suspension, they made no light, But when they grew to a certain cell number all the bacteria turned on light simultaneously"(Bassler 2009). The bacteria were able to detect when they were alone and when they were clustered in a community but communicating with one another. I have to be honest, this was a Copernican-esque turn for me. 

Too often, we relegate the power of communication to more evolved organisms, not tiny, unicellular bacterium. Our exclusivity of communication ignores the idea that even electrons and protons, the smallest elements of life, communicate with one another. Bacteria work together in order to achieve one specific goal, in some ways, their actions are purposive. For example, a single bacterium can secrete toxins into a human, but it is unlikely that the actions of one will actually effect the human body as we are enormous and complex organisms. Instead, "they get in you, they wait, they start growing, they count themselves...and they recognize when they have the right cell number that if all of the bacteria launch their virulence attack together." (Bassler 2009) Bacteria hold power in their control of pathogenicity, but is it through will (can I even go as far as to say a 'lowly' bacterium has a will) or programming for survival? 

What was so incredible about Bassler's work is that she and her team discovered a molecule called AI-2, a fixed carbon molecule shared by many species of bacteria. Every bacterium has “the same enzyme and makes exactly the same molecule. So they’re all using this molecule for interspecies communication. This is the bacterial Esperanto.” (Bassler 2009) Through this discovery, Bassler and her team are now focusing on drug resistant bacteria (drug resistance being a characteristic that derives from the bacteria's ability to communicate with one another), and redesigning antibiotics in the 21st century. The inhibiting of intraspecies and interspecies communication systems is key, and Bassler's team are developing a molecule that would basically jam the receptors of hte bacteria, thus making a "species-specific, or disease-specific, anti-quorum sensing molecules." (Bassler 2009) With this, Bassler hopes to create a universal antibiotic that will work against all bacteria.