Synthetic biology when it comes to food is a hot topic these days. It seems that every grocery store shopper has an opinion about genetically modified foods, many of which are created using synthetic biology techniques. It appears that synthetic biology may have gotten an unfair reputation, however, due to a lot of inaccurate information available in mainstream media. A good example, took place during one of my favorite TV shows this past Monday.

In general, I enjoy watching the CSI series shows (Miami and Vegas, not New York). I like them, because I think it creates great exposure for technical science on TV. I appreciate the attempt to create authenticity for the audience and I choose not to dissect the generally minor inaccuracies of the show just because I have the training to do so. However, in the case of last week’s episode, and given this week’s Symposium on Synthetic Biology in Toronto, I thought it was important to set the record straight.

Last Monday’s episode of CSI Miami took on foodborne illnesses and involved a young boy and girl who in the end both die of illnesses related to the consumption of food at a local restaurant a few days earlier. The CSI team investigates the death of a young girl, and traces that back to an E. coli infestation at a local produce farm due to a contaminated water supply. Then, her boyfriend also becomes ill with a mysterious illness. Initially it is believed to be E. coli as well, but soon it becomes clear that it is not the same illness. Tissue samples reveal that the boy is ill with botulism, an illness that causes paralysis and death due to the presence of botulinum toxin. Normally, botulism is caused by improperly prepared canned food that contained the bacteria Clostridium botulinum. The bacteria itself is not harmful, but if allowed to grow in an environment without oxygen (anaerobic), the bacteria produces botulinum toxin, one of the most lethal substances known to man (average kill dose is in the range of about 50 – 90 nanograms). At this point, I am intrigued.

The team determines that the boy’s meal at the restaurant where his girlfriend became sick with the E. coli was a veggie burger and a corn on the cob. Nothing in the meal at first glance points to a source of the botulinum toxin. Now enters synthetic biology. The team earlier uncovered a genetically modified corn produced by the same company owning the farm that is the source of the E. coli. By no small coincidence, it turns out that this genetically modified corn is the corn on the cob that the boy ate causing him to become sick. How did the botulinum toxin end up in the corn?

Here is where the authenticity begins. Corn contains a very high quantity of cellulose, a substance that humans know as “fiber” or “roughage” because we cannot digest it. The fictitious company in the show decided to engineer their corn to produce an enzyme that could digest the cellulose, thus making their corn more pleasant to eat (and easier to digest). The CSI team explains to the viewer that this was done by using a Clostridium species gene implanted into the corn giving the corn cells the ability to produce the enzyme that digested the cellulose. They go on to explain that it appears that an unfortunate exchange of genes in the Clostridium culture allowed for the botulinum toxin gene to also be transferred to the corn cells. They explain that this occurred unknowingly through bacterial conjugation. The corn cells then produced the botulinum toxin in addition to the cellulose enzyme causing the boy’s death. It all sounds true right?

In truth, a lot of it is true. Bacterial conjugation is a real process where genetic material is exchanged between bacterial cells in natural or laboratory environments. It is true that it is unpredictable, and so it is believable that the fictitious company scientists obtained the result unknowingly. There are over 10 species of Clostridium bacteria that produce cellulosomes (a complex of enzymes that digest cellulose) and we of course know that botulism is real.

Could the boy have died? In actuality, he could have, but only if he had eaten the corn on the cob raw, and personally, I don’t know anyone who eats raw corn. Botulinum toxin is a protein which is rendered ineffective by heating, and it doesn’t take much heating to render the toxin completely harmless. In fact, corn on the cob heated to only 80 degrees Celsius for less than 1 minute would have been enough to neutralize the toxin. I’ll assume that the restaurant cooked the corn the same way I would, by boiling it, or barbecuing it and so I’m pretty sure that the corn would have achieved at least these temperatures.

In the end, there’s not a lot wrong with the science which makes us believe that the story is true. It makes us worry, that a real company could one day create corn that could give us botulism. The company in the show is portrayed as being pretty unethical, and not that concerned about consumer safety. This contributes to further slant our opinion of the science at hand. All of these elements are things that scare us, and things that lead us to have those conversations about the negative aspects of synthetic biology at the grocery store. However, the information on the heat sensitivity of the botulinum toxin is right on the Wikipedia page for the botulinum toxin (although, they say 60 degrees Celsius, the academic literature I read was more convincingly around 80 degrees Celsius). CSI Miami writers could have looked it up, and so can you.

My point is that a lot of what you hear about synthetic biology in the mainstream media is simply not true. Make sure you educate yourself about it, before you write it off. Synthetic biology isn’t just about engineered foods, it has the potential to allow us to do many things, including making biofuel, using bacteria to produce medicine, and creating foods that are resistant to disease and weather. TV science might seem real, but in the end, it is just TV.