Lab engineers macroscale, modular materials from bacteria

Lab grown living materials display potential to aid efforts in human health, energy, and environmental remediation. Now engineered living materials can be fabricated big and customized with less effort.

In a new development, bioscientists at Rice University have introduced centimetre-scale, slime-like colonies of lab grown bacteria that assemble on their own from bottom up. The engineered bacteria can be modelled to absorb contaminants from the environment or to stimulate biological reactions, among many possible applications.

“We are creating matter from bacteria that works like putty’” stated one of the bioscientists at Rice University. One of the beautiful things about the material is how easy it is to make, which merely requires a few nutrients, little motion, and bacteria.

A study published in Nature Communications provides details of the lab’s creation of flexible, adaptable engineered living materials (ELM) using Caulobacter crescentus as a biological building block. While the engineered bacteria can be genetically modified for various operations, the design and assembling has been long and complicated.

This involved engineering the bacteria to display and secrete the biopolymer matrix for the material to have its form. The expression of the Caulobacter crescentus on a protein that covers its outer membrane is akin to scales on a snake.

The bacteria was modified to express a version of that protein, which they called BUD (bottom-up de novo), with characteristics that are not only favorable for forming BUD-ELMs, but also provide tag for future functionalization.

The objective was to prove it is possible to grow materials from cells, how a tree grows from a seed, stated the lead author of the study. The transformative part of engineered living materials is that they contain living cells that allow self-assembling of the material and self-repair in case of damage.