Production process development and safety analysis of domestically isolated Clostridium butyricum S-45-5

The discovery and industrial application of functional microbial strains with probiotic potential have gained global attention. This study focused on Clostridium butyricum S-45-5, a butyrate-producing strain isolated from the feces of breastfed infants in Korea and transferred from the Korea Research Institute of Bioscience and Biotechnology (KRIBB, Jeongeup, Korea). Comparative analyses were conducted with representative commercial strains, including MIYAIRI 588 (Japan) and CGMCC0313 (China), to evaluate origin, cultivation characteristics, and industrial applicability. The S-45-5 strain exhibited superior productivity, stable fermentation profiles, and consistent viable cell counts under large-scale production conditions. Comprehensive safety assessments, including toxicity, antibiotic resistance, and pathogenicity tests, confirmed its compliance with international probiotic safety standards. These findings demonstrate that C. butyricum S-45-5 is a safe and robust probiotic candidate suitable for commercial use. Furthermore, ongoing registration for Generally Recognized As Safe (GRAS) status with the U.S. Food and Drug Administration (FDA) and forthcoming human clinical trials are expected to support its global commercialization. The establishment of a stable mass-production process highlights the potential of S-45-5 as a Korea-origin butyrate-producing probiotic with broad industrial and functional applications.