In a world increasingly overwhelmed by plastic, all the way from the deepest ocean trenches to the highest mountain peaks—its harmful impacts are becoming clearer than ever. As plastic accumulates in waterways, threatens wildlife, leaches chemicals, and enters the food chain, the search for alternatives is gaining steam.
Finding sustainable alternatives to plastic has driven M.A.S.R. Saadi, a doctoral student at Rice University in Houston, Texas, to study converting bacterial cellulose, a natural and biobased material, into a multi-purpose alternative to plastic.
Spinning bacteria into the future of materials
“The urgency to replace synthetic plastics with greener alternatives is central to addressing environmental and climate challenges,” Saadi said. “It is the most abundant biopolymer on Earth and can be sourced from both plants and microorganisms.”
Unlike plant-derived cellulose, which often carries impurities, bacterial cellulose is remarkably pure. Its nanofibrillar structure offers a promising solution to the plastic problem, with potential uses in everything from water bottles and packaging to wound dressings and other everyday products.
“Inspired by growing global efforts—particularly in Europe—to upcycle microbial materials, I recognized bacterial cellulose as a promising candidate. As a materials engineer, I wanted to push its potential further through careful design and engineering, transforming it into a robust, multifunctional alternative to plastics,” Saadi said.
Reflecting growing concerns about plastic pollution, the European Parliament voted in 2019 to ban single-use plastic items—such as straws, food containers—an effort to reduce marine litter and promote sustainable alternatives.
From lab innovation to scalable sustainability
Saadi’s paper presents a simple, scalable method to create strong bacterial cellulose sheets and multifunctional hybrid nanosheets using fluid flow in a rotational culture device. The resulting materials boast high strength, flexibility, foldability, transparency, and long-lasting mechanical stability, he said.
One of the most innovative aspects of the project was creating a custom-designed rotational culture device where cellulose-producing bacteria is cultured in a cylindrical oxygen-permeable incubator continuously spun using a central driveshaft to produce directional fluid flow.
It took about seven to 10 days to grow the bacteria with the team working on such issues as preventing mold growth.
To enhance the cellulose and expand its functionality, the team added boron nitride nanosheets to the bacterial feed solution, producing bacterial cellulose–boron nitride hybrid nanosheets with superior mechanical strength (tensile strength reaching approximately 553 MPa) and improved thermal performance (dissipating heat three times faster than control samples).