Gas Fermentation: A Game-Changing Technology from Molecular Engineering to Bioreactors, Modeling, and Optimizing Processes and Apparatuses

Against the backdrop of an increasing global demand for sustainable energy sources, construction materials, and high-quality food to support a growing population, there is heightened research interest in the biotransformation of gaseous substrates. These substrates serve as critical sources of carbon and energy for unique microorganisms that utilize methane, carbon monoxide and carbon dioxide, and hydrogen as nutrients. In addition to the fundamental scientific interest in addressing the mathematical modeling challenges in the biophysics and biochemistry of microorganisms, this research area is characterized by its significant practical implications. Researchers are focusing on several task classes: the application of genetic engineering to optimize metabolic processes for the efficient production of a broad spectrum of products; the study of key biocatalytic enzymes; and the development of innovative engineering solutions for bioreactors. These novel reactor designs aim to enhance process controllability, safety, and efficiency while reducing production costs. To assess the comparative efficiency of existing and emerging bioreactors—particularly regarding mass transfer characteristics and energy consumption—a wide array of tools is now available. These include mathematical methods for describing two-phase gas–liquid systems and hydrodynamic processes, as well as advanced computational techniques such as supercomputing, machine learning algorithms, and neural networks. This work presents several examples and outlines contemporary trends in the development of gas fermentation.