In this study, a non genetically modified strain of Streptomyces fradiae was cultured on ISP medium No. 4 medium supplemented with 1 % glycerol, casein, peptone, and yeast extract, and incubated at pH 7.2 and 27 °C for 7 days. Microbial transglutaminase (MTG) was purified using Q-Sepharose chromatography, and its molecular weight was determined to be 35.6 kDa via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The purified MTG exhibited optimal activity at pH 8.5 and 50 °C. The enzyme\\\\\\\'s half-life was 88.12 ± 0.32 min at 30 °C and 49 ± 0.8 min at 50 °C. Additionally, the Kₘ and Vₘₐₓ values of the MTG reaction were 0.74 μM and 100.5 U/mg, respectively. The addition of 1 % MTG to the yogurt production process significantly reduced the pH from 4.8 to 4.5. Furthermore, syneresis decreased from 2.8 % to 1.5 %, indicating an improvement in the structure and quality of the treated yogurt. The isolated MTG significantly reduced blood clotting time in vitro from 457 ± 2 to 265 ± 2.5 s. In vivo, enzyme application led to a significant reduction in hemostasis time and blood loss in liver tissue. Moreover, histological observations revealed reduced liver damage and hemorrhage after 7 days. Overall, this study first reports that MTG from S. fradiae exhibits great potential as a biocatalyst in both the dairy industry and medical applications.

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