Enhanced production of Nattokinase by Bacillus aryabhattai RP6 isolated from fermented Brassica oleracea

Nattokinase (NK) in recent times has been identified as an important enzyme for its health benefits and its application in cardiovascular diseases (CVD). NK is known for its thrombolytic activity and has been actively used its low cost of production. The research study aims to enhance the Nattokinase production from fermented Brassica oleracea. Seven different fermented and non-fermented food sources were screened for fibrinolytic protease-producing bacteria. Out of 12 bacterial isolates, 7 were identified as protease producers. However, the strain RP6 isolated from fermented Brassica oleracea exhibited higher fibrinolytic activity. Morphological, biochemical, and molecular characterization revealed RP6 as Bacillus aryabhattai. Optimization studies showed maximum NK production when glycerol and ammonium chloride were used as carbon and nitrogen sources, respectively, at pH 10, inoculum size of 2%, and incubation at 37 °C. The purified enzyme, with an apparent molecular mass of 29 kDa, demonstrated maximum fibrinolytic activity of 88.87% after 3 h. The study identifies Bacillus aryabhattai RP6 as a potent NK-producing strain. Its high yield and strong fibrinolytic activity highlight its potential for industrial-scale NK production and possible application in cardiovascular therapeutics.