Partial purification and characterization of an extracellular cold-active protease from <i>Flavobacterium azizsancarii</i>, a novel Antarctic isolate


Otur Ç.

BRAZILIAN JOURNAL OF MICROBIOLOGY, vol.57, no.1, 2026 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 57 Issue: 1
  • Publication Date: 2026
  • Doi Number: 10.1007/s42770-026-01979-9
  • Journal Name: BRAZILIAN JOURNAL OF MICROBIOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, MEDLINE, Latin America & Iberia Database (ProQuest), Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Health Research Premium Collection (ProQuest)
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

Cold-active enzymes exhibit high catalytic efficiency at low temperatures, making them valuable biocatalysts for energy-efficient and environmentally friendly industrial processes. The enzymatic activity of bacteria that thrive in low-temperature environments has attracted the attention of researchers. In this study, an extracellular cold-active protease produced by Flavobacterium azizsancarii (F. azizsancarii), a novel Antarctic isolate, was partially purified by ammonium sulfate precipitation and dialysis. The enzyme showed maximal activity toward casein at pH 8.0 and 20 degrees C. The effects of various metal ions on protease activity indicated that Ca & sup2;(+) did not result in a significant change in activity, whereas Fe & sup2;(+), Zn & sup2;(+), Mg & sup2;(+), and Mn & sup2;(+) significantly inhibited proteolytic function. The enzyme was inhibited by organic solvents, including ethanol, methanol, acetone, toluene, and benzene, and was significantly and partially inhibited by PMSF, suggesting the possible presence of a serine-type protease component. These findings demonstrate that F. azizsancarii produces a cold-active alkaline protease with promising biotechnological potential, particularly for food processing, detergent formulation, and protein hydrolysate production.