Gas Biological Conversions: The Potential of Syngas and Carbon Dioxide as Production Platforms

Contemporary challenges in decreasing Green House Gas emissions and finding alternative carbon and energy sources for fueling our society brought in the forefront processes based on biological conversions of gaseous substrates, such as syngas and carbon dioxide. Generation of synthesis gas or syngas (a gaseous mixture mainly of CO, H₂ and CO₂ generated during thermal decomposition of carbonaceous material in the presence of limited amount of an oxidizing agent) is known since the beginning of the 17th century and discovery of Fischer–Tropsch synthetic route in the beginning of the 20th century allowed the development of various routes for chemical catalytic synthesis of fuels and chemicals from syngas. Biological processing of syngas came in the forefront much later, following important advances within Microbiology and Biochemistry disciplines. This thermo-biochemical route for production of low-value products like fuels is considered competitive and advantageous compared to the thermochemical route when small-scale installations are concerned. Production of higher value products via the carboxylate platform is also a promising, and certainly worth-investigating route. Biological conversion of syngas and valorization of CO₂ via biological means, besides contributing in greening our world, come with similar product portfolio and share the same technological challenges. Therefore, the target of the current study is to provide an overview of the latest scientific advances within syngas and CO₂ valorization to fuels and chemicals and industrial applications and propose a way forward taking into account contemporary challenges and needs. Graphical Abstract: [Figure not available: see fulltext.]