The inclusion of a plastic-eating enzyme into the manufacture of polylactic acid (PLA) can make the material biodegradable, say researchers at the Toulouse Biotechnology Institute and French biotechnology company Carbios.
The researchers optimized an enzyme to withstand the 160 C (320 F) temperatures of molten PLA during its manufacturing process and added it without modifying any production lines. The so-called enzymatic PLA then degraded fully under home composting conditions in 20–24 weeks, which is less than the 26 weeks needed for certification to be home compostable, leaving no microplastics. The material remained intact in storage and is compatible with industrial packaging applications.
Carbios has an operational production line capable of producing 2,500 metric tons (2,756 U.S. tons) of the Carbios Active enzyme per year, which would create 50,000 metric tons (55,116 U.S. tons) per year of enzymatic PLA.
The study was published in Nature in July 2024.