Scientists think their biotechnology breakthrough could end plastic waste forever
Earth.com’s writer
In 2024, an estimated 485 billion pounds of plastic waste was generated globally, making it extremely challenging to manage. Plastic waste often lasts for centuries, so researchers are looking for materials in nature that can safely disappear after use.
Maqsood Rahman, a mechanical engineer at the University of Houston, and his team at Rice University have created bacterial cellulose sheets that are as strong as metal but can decompose like paper.
Why are bacterial cellulose sheets useful?
This biopolymer comes from the cell walls of species such as Novacetimonas hansenii. It forms thin ribbons, just a few nanometers thick, that bond like Velcro and can reach tensile strength over 400 MPa.
Why are bacterial cellulose sheets useful?
This biopolymer comes from the cell walls of species like Novacetimonas hansenii, creating ribbons that are only a few nanometers thick.
The fiber network is compatible with human tissue, making it an effective, transparent wound dressing that decreases pain and speeds up healing.
| RCSB-PDB-4HS4: Crystal structure of a putative chromate reductase derived from Gluconacetobacter hansenii, Gh-ChrR, containing the Y129N substitution. | Scanning electron microscopy image of K. hansenii ATCC 23769 and its CS… |
Dr. Maksud Rahman, a BUET Mechanical Engineer and now Assistant Professor at the University of Houston, stated, “We believe these strong, versatile, and eco-friendly bacterial cellulose sheets will widely replace plastics in many industries, reducing environmental harm.”
He explained that bacteria inside an oxygen-permeable cylinder rotate slowly, swim in one direction, and align their strands side by side. This process converts random mats into organized wires, achieving a strength of 436 MPa and a modulus of 32 GPa.
Researcher Dr. M. S. R. Saeedi said, “The resulting bacterial cellulose sheets exhibit high tensile strength, flexibility, foldability, optical transparency, and long-term mechanical stability.”
Bacteria grow cellulose sheets
The team mixed hexagonal boron nitride flakes, a 2D material with a Young’s modulus of about 0.8 TPa and thermal conductivity over 700 Wm⁻¹K⁻¹.
Maqsood Rahman states that trapping flakes between cellulose ribbons increased strength to 553 MPa and improved heat dissipation by three times, making this single-step process a scalable and versatile method for synthesizing various nanomaterials.
Real-life uses of the bacteria sheets
The tough sheet can be folded into a disposable water bottle, lined with a shipping bag, or reinforced with fiber-based electronics, all without producing microplastic waste.
Biomedical companies are focusing on a platform for burn dressings and tissue scaffolds. Bacterial cellulose absorbs fluid while gradually releasing it, keeping wounds moist.
Petroleum-based plastics resist microbial attack due to their carbon structure, while cellulose decomposes during composting, releasing excess CO₂ into the atmosphere.
Retention over time
A lab reactor currently produces about 7.5 mg per day. Industrial drums will need to significantly increase this output without disturbing the fragile oxygen balance needed for the microbes.
Boron nitride is expensive and impacts mining, so engineers will explore other mineral plates or plant-based nanofibers that might offer similar toughness at a lower price.
Durability tests showed that the spun-bonded bacterial cellulose sheets retained their shape and strength even after 10,000 mechanical loading cycles.
Under stress conditions that mimicked real-world fatigue, their structure remained intact with no visible fractures or surface separation.
The material can endure repeated tension, making it suitable for long-term use in flexible electronics, medical devices, and lightweight structures that require both elasticity and stiffness.
Blending with other materials for new properties.
The research team enhanced strength and thermal conductivity using boron nitride nanosheets, but the setup could also support other additives.
Materials like graphene oxide, cellulose nanocrystals, and clay nanosheets offer properties such as conductivity, flame resistance, and moisture control, based on their use.
Because bacteria spin cellulose in real time, the added particles are embedded directly into the fiber network.
This allows researchers to customize the behavior of each sheet during growth, rather than requiring additional manufacturing steps after production.
Life cycle assessments, regulatory scrutiny, and consumer perception studies are on the horizon, but the flow-guided approach suggests a future where packaging energy doesn’t lead to lasting pollution.
How to scale up bacterial sheet production
The setup uses a custom rotating culture device that spins at 60 rpm and generates about 7.5 mg of dry material daily.
This works for lab experiments, but industrial applications will require much larger volumes and faster throughput.
To scale up, engineers will need to optimize oxygen flow, nutrient cycling, and bacterial strain performance while keeping alignment intact.
If successful, the method could be adapted to existing fermentation or bioreactor infrastructure with minor retrofitting.
Bacterial Cellulose Sheets vs. Plastics and Metals
Expanded bacterial cellulose sheets outperform many commercial polymers and glass in tensile strength and Young’s modulus relative to density, as shown on an Ashby plot.
These charts show that the material achieves stiffness values close to those of some metals and is much lighter.
Its strength-to-weight ratio makes it appealing for aerospace, structural packaging, and thermal insulation, where reducing weight is crucial without sacrificing performance.
The research is published in Nature Communications.
The study is published in Nature Communications.
Courtesy of Earth.com
