Pollution to products: recycling of ‘above ground’ carbon by gas fermentation

[Display omitted] •Gas fermentation is an emerging technology for sustainable fuel/chemical production.•A wide range of local, abundant, waste, and low-cost resources can serve as input.•The technology has successfully been proven at full commercial scale.•A range of sophisticated genetic tools have been developed over the last decade.•More than 50 products have already been demonstrated through gas fermentation. Climate crisis and rapid population growth are posing some of the most urgent challenges to mankind and have intensified the need for the deployment of carbon recycling and carbon capture and utilization (CCU) technologies. Gas fermentation offers a solution using carbon-fixing chemolithoautotrophic microorganisms. After a decade of scale up, the technology has recently been commercialized with the first plant operating successfully since 2018 and additional units under construction. Gas fermentation offers unique feedstock and product flexibility when compared to other available gas-to-liquid technologies. Advancements in process technology and synthetic biology enable a broad range of feedstocks including emissions from industry or syngas generated from any biomass resource to be converted into a wide range of molecules realizing a circular economy.