What happens when geneticists play with their food?

DNA dumpster dive

The story of Elinne Becket’s latest pet project starts in January, on the weekend after her birthday. Her mother gave her a pot of beef soup, a gift that Becket eagerly awaits every year. By the time February came to a close, Becket, a microbiologist at California State University San Marcos, realized not only that she had forgotten a couple of bowls’ worth in the back of her fridge but also that the soup had turned a stomach-​turning-​yet-stunning shade of blue. Becket says the soup’s “supersecret proprietary recipe” doesn’t contain any cabbage, onion, or beets, which could have imparted bluish anthocyanins or betanin.

She dumped the soup in the trash and then took to Twitter to ask the microbiology community what would cause the bright blue hue. A few encouraging replies later, Becket found herself elbow deep in the trash can, using cotton swabs to gather samples of the beef-and-vegetable medley for analysis.

Among those following the saga was Becket’s Twitter friend and collaborator Sebastian Cocioba, the owner of the genetic engineering contracting company New York Botanics. Cocioba, who is known online for his at-home lab adventures, asked Becket to mail him some of the blue swabs so the duo could set out to identify the colorful culprit.

The team so far suspects that a bacterium was behind the change, and a bluish bacterial colony that Cocioba was able to culture from a swab matches the profile of a couple of Pseudomonas species. Becket’s initial RNA sequencing data also showed that most of the bacterial community is made of pseudomonads, and she has amassed discarded or slightly expired supplies for metagenomic analysis. “We don’t have funding for this project, obviously. And so we have to scrounge for available resources,” she tells Newscripts.

Both Becket and Cocioba champion open-source science, and you can follow their progress on Becket’s Twitter page. “We’re doing it as kind of a social experiment: Can you do a lab notebook in a tweet thread?” Cocioba asks.

The duo say the open notebook is meant to demonstrate that purely exploratory science is meaningful. The project “has reminded everyone why we got into science, which is to just explore things out of curiosity without the burden of trying to appeal to grant reviewers,” Becket says.

Don’t eat the worm. Sequence it

The adage goes something like, “You won’t find answers at the bottom of a bottle,” yet researchers at the Florida Museum of Natural History have done just that. On a balmy night, after doing field research in Oaxaca, Mexico, Akito Kawahara’s team pondered the identity of the storied worms that lie at the bottom of mezcal bottles. Although some people say the worms impart color, flavor, and aphrodisiac properties to the liquor, the researchers say that they became common in the 1950s as a marketing stunt that just worked really well.

Kawahara’s interest shouldn’t be a surprise considering that his phylogenetics lab studies the evolution of insect species’ traits and genes. After some debate and close inspection of several bottles of mezcal, the team figured they were looking at one of three species. Among them was Aegiale hesperiaris, commonly known as the tequila giant skipper; its name “is what started all these questions,” says Jose I. Martinez, a curatorial assistant in Kawahara’s lab. Despite the critter’s nickname, the team realized that bottles of authentic tequila—which is a type of mezcal made exclusively with blue agave—never contain a worm. Also, larvae of this species cost about $250 per kilogram, so it seemed unlikely that they’d be used as a novelty.

Back in Florida, the team got to work sequencing the genomes of larvae from different mezcal brands and ID’d each species. Of the 18 larvae they were able to sequence, they got the same result: all the larvae were chinicuiles (Comadia redtenbacheri), caterpillars that are commonly eaten fried or roasted in many parts of Mexico (PeerJ 2023, DOI: 10.7717/peerj.14948).

The results were not necessarily surprising, but Kawahara and Martinez tell Newscripts it’s important for scientists to step back every once in a while and think about how their work relates to things that people experience every day. Plus, “the sequencing part was not expensive,” Kawahara adds. “Purchasing the alcohol was a whole other issue.”

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