Statistical optimization for improved production of fibrin(Ogen)olytic enzyme by Bacillus cereus strain FF01 and assessment of in vitro thrombolytic potential of protease enzyme

An extracellular fibrin(ogen)olytic protease-producing bacterial strain (FF01) was isolated from a rice beer alcohol producing starter culture of North East India, Assam. Initially, Plackett–Burman design was applied to screen the significant factors influencing the yield of fibrinolytic enzyme (measured in terms of fibrinolytic/caseinolytic ratio) in submerged fermentation after 24 h of incubation at pH 8.0 and 37 °C. Further, response surface methodology (RSM) associated central composite design showed optimum enzyme production after 120 h of incubation with 0.0057% (w/v) of casein and 0.0318%( w/v) of ammonium sulfate at pH 8.0 of the modified M9 medium. This resulted in 5.24 fold enhancement of fibrin(ogen)olytic enzyme production from this bacterium with a corresponding increase in F/C value of culture supernatant from 85 (from initial, unoptimized conditions) to 446 (production under RSM optimized conditions). The partially purified fibrin(ogen)olytic enzyme surpassed plasmin and streptokinase in dissolving the thrombus under identical experimental conditions suggesting future therapeutic application of enzyme under study in the treatment of hyperfibrogenemia and prevention of cardiovascular relevant disorders is highly promising.