SELF-ASSEMBLING BACTERIA CAN MAKE A BETTER DRUG FACTORY

Various strains of genetically engineered bacteria have been used as industrial workhorses for years. It’s a straightforward idea: you engineer a bacterium’s genome so that when it eats specific things, it exudes or excretes the exact product you want.

Engineered bacteria are making drug compounds, neutralizing toxic waste, and serving a range of other useful purposes.

Researchers at Rice University have streamlined the process of making the bacteria themselves, which has always added time and cost to bacteria-based projects.

The scientists chose a bug called Caulobacter crescentus because it can display a wide variety of proteins on its surface, making it a utility player for industry.

The Rice group tinkered with the bacterium’s genome so that it “self-assembles from the bottom up,” the scientists reported.

That means each bacterium grows from a single engineered cell without further intervention. Put the designer cells in a nutrient medium, set them aside, and come back a day later when the bacteria have reached about a centimeter in size, roughly a third of an inch.

The microbes were engineered to secrete a biopolymer matrix that gives their mass some form, and also are “tunable,” meaning their genomes can be engineered to carry out a wide range of functions.

Self-assembly can save time; it also can cut costs by dispensing with specialized equipment and lab technicians, making “biomanufacturing” available to a range of products and industries that might not have been able to adopt it yet.

The materials, which are shelf-stable for about three weeks, can repair themselves if damaged on the job, so they also last longer and require less human intervention.

In tests, the designer bugs performed as they were engineered to do, including, in one case, pulling cadmium from a water sample.

The new materials are likely to find uses as filters, aids in fermenting and homogenizing, and in making plastics, detergents, and even protein supplements for humans.

TRENDPOST: Biomanufacturing can be simpler, cleaner, and cheaper than using the usual array of machines and synthetic chemicals. As a result, it will claim a larger role in producing a range of products.

However, the same concerns about pollution remain. Not only is there the issue of noxious waste, but also of containing bugs that could mutate or cause unforeseen havoc if they escape into the wild.