Characterization of Butanol‐producing Strains: Physiology and Biochemical Functions of Solvent‐producing Bacterial Strains

Native butanol-producing bacteria typically belong to nonpathogenic solventogenic Clostridium species, which have attracted significant attention as industrial workhorses to produce fuels and bulk chemicals. These Clostridium species can metabolize a wide range of substrates, including glucose, xylose, arabinose, mannose, galactose, maltose, cellobiose, starch, dextrin, and malto- and xylo-oligosaccharides, to support energy production and growth. The diversity among solventogenic Clostridium species extends beyond substrate utilization profiles. They also exhibit considerable variation in genome sizes, the presence or absence of plasmids, and energy-generating pathways such as the Embden–Meyerhof–Parnas pathway, the pentose phosphate pathway, and the phosphoketolase pathway. Furthermore, these microorganisms can produce a broad spectrum of industrially relevant chemicals and fuels, including acetone, butanol, hexanol, ethanol, 1,3-propanediol, exopolysaccharides, isopropanol, and hydrogen. Comprehensive physiological and biochemical characterization of native butanol-producing Clostridium strains is essential to deepen our understanding of their metabolic potential and to inform strategic process and metabolic engineering efforts aimed at overcoming challenges associated with their commercial application in biorefineries.