Publisher Summary The syngas can be converted into liquid biofuels through Fischer-Tropsch (FT) synthesis (using metal catalysts) or direct microbial fermentation knownas syngas fermentation (using microbial catalysts). The FT synthesis usually utilizes metal catalysts such as cobalt (Co), ferrous (Fe), copper (Cu), aluminum (Al), zinc (Zn), molybdenum (Mo), nickel (Ni), rubidium (Ru), and ruthenium (Rh). The major drawbacks of FT synthesis are the high costs of the metal catalyst, a fixed H2:CO ratio (2:1), catalyst poisoning due to inert gases and contaminants containing sulfur, and high operating temperature and pressure. Syngas fermentation via biocatalysts (such as Clostridium ljungdahlii, C. autoethanogenum, C. carboxydivorans, Butyribacterium methylotrophicum, Methanosarcina barkeri, and Rhodospirillum rubrum) produces liquid/gaseous biofuels, and offers several advantages over the biochemical approach and the FT process. Some of the merits of syngas fermentation are the elimination of the need of expensive metal catalysts, a higher specificity of the biocatalysts, the independence of theH2:CO ratio for bioconversion, the operation of bioreactors at ambient conditions, and the elimination of issues concerning noble metal poisoning Biomass-derived syngas fermentation to biofuels is identified as a sustainable alternative for the fast depleting fossil-derived fuels. The process has several advantages including higher availability, low feedstock cost, and no competition with food and feed. The commercialization of syngas fermentation to biofuels is often plagued by the gas-to-liquid mass transfer limitations and low product yield. Innovative reactors designs and metabolic engineering aspects are being studied extensively in recent literature focusing on higher product yields. Use of CHFM (composite hollow fiber membrane) in syngas fermentation is at its infant stage and needs extensive research to prove its economic and scale-up feasibilities. Similarly, research efforts should also be directed toward production of other biofuel such as butanol and gaseous fuel, methane.