Engineered Bacteria Turn Potato Starch into Biodegradable Bioplastic in Just 24 Hours

In a significant stride toward solving the global plastic pollution crisis, researchers at the University of Barcelona have developed a novel method to produce high-value biodegradable bioplastic—polyhydroxybutyrate (PHB)—directly from raw potato starch. The process, which takes only 24 hours in a single fermentation step, bypasses the complex multi-stage procedures traditionally required. This breakthrough offers a promising strategy to reduce the world’s heavy dependence on fossil fuels for plastic production and to cut down on the persistent plastic waste that accumulates in landfills and oceans, while also lowering greenhouse gas emissions associated with conventional plastic incineration.

At the core of this innovation is the bacterium Bacillus subtilis, a safe and widely used industrial microorganism. Using the CRISPR-Cas9 gene-editing tool, the scientists modified the bacterium’s metabolism by introducing the amyQ gene, which encodes the enzyme α-amylase. This genetic tweak enabled the bacteria to efficiently break down starch and convert it into PHB in one integrated step. Laboratory results were impressive, yielding 11.3 g/L of biomass and 5.8 g/L of PHB, with the polymer accounting for 51.8% of the cells’ dry weight—figures that are fully competitive with current commercial standards. Since PHB is derived from renewable resources and is fully biodegradable, this technology represents a viable, eco-friendly alternative to petroleum-based plastics, helping to reduce both the carbon footprint and the accumulation of persistent waste in nature.