“Slack”teria Compete in 76th Annual Hunger Games
Group projects: every student’s nightmare. Well, not every student. Granted, there is the occasional lab partner FedEx’d straight from Heaven who pulls her weight. Unfortunately, not everyone is the perfect Timon to your Puumbaa, and you are left struggling under the weight of the assignment while your partner, Houdini, perfects their vanishing act.
This phenomenon can scarcely be escaped, even on a microscopic scale. Certain organisms are more productive than others, caused by cellular “noise,” or natural randomness. On the bright side, at a microbial level, you can wipe out the unproductive cells and they will not be missed.
Studies conducted at Washington University, under Fuzhong Zhang, on Escherichia coli work to reward hardworking bacteria and eliminate the slackers in a productivity Hunger Games. Two strains were studied: one produced free fatty acids used for biofuels, while the other makes the amino acid tyrosine, a pharmaceuticals precursor. Truthfully, only some within each cohort actually produced the required chemicals, while the others mooched off of the available nutrients.
Researchers separated goats from sheep by applying an intracellular population quality control, referred to as “PopQC.” This biosensor was inserted in vivo, and monitored the abundance of the bacteria’s product. If the organism would be doing its job, it would then be rewarded with a protein that regulates the bacterial cell membrane’s permeability to the antibiotic tetracycline, allowing it to live and thrive. If a bacterium fails to meet its quota, this specific protein would not ne released, and the lazy cell would perish at the metaphorical hands of tetracycline.
This survival-of-the-fittest quality-control mechanism maximized the production of the desired chemical products by eliminating the piggybacking group members. The available space and nutrients were thereby allocated to productive members of the bacterial society. The results showed a 300% increase in production of both studied strains of E. coli.
Zhang applied for a patent, and further claimed that this approach may be used for various other biosynthetic pathways, so long as the host is respondent to the intracellular biosensor. Using similar methods on CEGEP classmates may be deemed “insensitive” and “inhumane,” for the time being.