Microbes and Microalgae: Biotech Takes on Air Pollution and Plastic Waste

Biotechnology is emerging as a key tool against pollution and plastic waste, with projects ranging from microalgae that purify urban air to engineered bacteria that break down PET plastic or convert it into vanilla flavoring. Globally, 19-23 million tonnes of plastic waste leak into aquatic ecosystems every year, and the World Economic Forum warns that oceans could contain more plastic than fish by 2050 if production remains uncontrolled. In response, researchers are engineering microorganisms with tailored DNA to degrade pollutants, recover resources from waste streams, and produce biodegradable alternatives.

One urban concept, the Liquid Planet project, uses biotechnology based on microalgae to capture CO₂, particulate matter and harmful gases from the environment while releasing oxygen. Described by the Minister for the Environment and Energy Security as "one of the most significant convergences between advanced biotechnology, public health and urban vision to have emerged in recent decades," the system frames photosynthesis as a new global economic system, addressing air pollution and climate change alongside economic sustainability.

Synthetic biologists are also expanding the range of engineered microbes beyond laboratory workhorses such as Escherichia coli and Saccharomyces cerevisiae. Scientists look in nature for microbes already capable of degrading contaminants, then use that knowledge to create organisms that do the job better. According to the chief innovation officer at LanzaTech, "Things are now feasible that were considered impossible a decade ago," enabling a shift toward a circular model in which waste is used for fuels, chemicals and materials. However, the field is held back by concerns about releasing genetically modified organisms into the environment and a lack of government funding and incentives.

In plastic waste management, engineered algae developed at the University of Missouri produce limonene, making them water-repellent so that microplastics stick to them and clump into a collectable solid mass. At the University of Edinburgh, scientists engineered E. coli to convert terephthalic acid—obtained by breaking down PET—into vanillin, the primary component of vanilla flavor. A team at Kobe University engineered E. coli to produce pyridinedicarboxylic acid (PDCA) from glucose as a sustainable alternative to PET, achieving concentrations more than seven times higher than previously reported. Researchers at North Carolina State University engineered a marine microorganism, working with Vibrio natriegens and Ideonella sakaiensis, to break down PET in saltwater. At the University of Waterloo, research explores microbial pathways that turn plastic into energy sources and enzyme-based methods that degrade PET in wastewater, including microbes that simultaneously metabolize carbon dioxide and plastic waste.

On the bioplastics front, bioplastics account for just 0.5% of the nearly 414 million tonnes of plastic produced annually, but global production capacity is expected to double from around 2.47 million tonnes in 2024 to approximately 5.73 million tonnes in 2029. Asia dominated in 2025 with about 55% of capacity, while Europe's share is set to increase from 14% to 17.2% by 2030. Experts attribute Asia's lead to strong state support, export-oriented industries, and strength in bio-based production, carbon capture and utilisation, and recycling. Europe, by contrast, has almost no support in market introduction, such as quotas or incentives. The European ViSS project is developing biobased and biodegradable PHBV plastic from poultry and sugar-industry residues through a non-sterile fermentation process; a PHBV pellet has already been developed in Spain with 10–15% and 20–30% 3HV content, and pilot demonstrators could launch by June 2026.