Białkowska AM, Krysiak J, Florczak T, Szulczewska KM, Wanarska M, Turkiewicz M. The psychrotrophic yeast Sporobolomyces roseus LOCK 1119 as a source of a highly active aspartic protease for the in vitro production of antioxidant peptides.
Biotechnol Appl Biochem 2018;
65:726-738. [PMID:
29569743 DOI:
10.1002/bab.1656]
[Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 03/15/2018] [Indexed: 01/19/2023]
Abstract
A psychrotrophic yeast strain producing a cold-adapted protease at low temperature was classified as Sporobolomyces roseus. In standard YPG medium, S. roseus LOCK 1119 synthesized an extracellular protease with an activity of approximately 560 U/L. Optimization of medium composition and process temperature considerably enhanced enzyme biosynthesis; an approximate 70% increase in activity (2060 U/L). The native enzyme was purified to homogeneity by cation exchange chromatography followed by a size exclusion step, resulting in a 103-fold increase in specific activity (660 U/mg) with 25% recovery. The enzyme displayed 10%-30% of its maximum activity at 0-25 °C, with the optimum temperature being 50°C. Protease G8 was strongly inactivated by pepstatin A, an aspartic protease inhibitor. The enzyme was used to hydrolyze four natural substrates, and their antioxidant activities were evaluated against 1,1-diphenyl-2-picrylhydrazyl. The highest antioxidant activity (69%) was recorded for beef casein.
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