Gas fermentation produces biopolymers for a sustainable plastics industry

Abstract

Plastic pollution is an escalating environmental concern, driving the urgent need for sustainable alternatives to conventional, petroleum-based plastics. Among the most promising solutions is the production of biopolymers, that is, natural polymers synthesized by living organisms such as microbes, plants, and animals. One innovative approach gaining attention is the use of gas fermentation technology, which converts industrial waste gases such as carbon dioxide (CO₂), carbon monoxide (CO), methane (CH₄), and syngas into valuable feedstocks for biopolymer production. This review delves into the integration of microbial fermentation processes with advanced bioreactor systems to efficiently produce biodegradable polymers, including polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and polyhydroxybutyrate (PHB). Key microbial pathways and genetic engineering strategies are explored to enhance the yield, productivity, and cost-effectiveness of biopolymer synthesis. Additionally, this review emphasizes the importance of life cycle assessment (LCA) and carbon capture and utilization (CCU) for minimizing greenhouse gas emissions and improving the process’s overall sustainability. Despite the promise, several technological and economic challenges remain, including gas insolubility, difficulties with large-scale implementation, and higher production costs than traditional plastics. The review also examines environmental policies, industrial innovations, and global initiatives supporting a circular bioeconomy. Through case studies and recent advancements, it highlights the transformative potential of gas fermentation-derived biopolymers in building a sustainable, carbon-neutral future for the plastics industry.