Bioconversion of agro-industrial wastes for the production of fibrinolytic enzyme from Bacillus halodurans IND18: Purification and biochemical characterization

Background: Agro-wastes were used for the production of fibrinolytic enzyme in solid-state fermentation. The process parameters were optimized to enhance the production of fibrinolytic enzyme from Bacillus halodurans IND18 by statistical approach. The fibrinolytic enzyme was purified, and the properties were studied. Results: A two-level full factorial design was used to screen the significant factors. The factors such as moisture, pH, and peptone were significantly affected enzyme production and these three factors were selected for further optimization using central composite design. The optimum medium for fibrinolytic enzyme production was wheat bran medium containing 1% peptone and 80% moisture with pH 8.32. Under these optimized conditions, the production of fibrinolytic enzyme was found to be 6851 U/g. The fibrinolytic enzyme was purified by 3.6-fold with 1275 U/mg specific activity. The molecular mass of fibrinolytic enzyme was determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis, and it was observed as 29 kDa. The fibrinolytic enzyme depicted an optimal pH of 9.0 and was stable at a range of pH from 8.0 to 10.0. The optimal temperature was 60°C and was stable up to 50°C. This enzyme activated plasminogen and also degraded the fibrin net of blood clot, which suggested its potential as an effective thrombolytic agent. Conclusions: Wheat bran was found to be an effective substrate for the production of fibrinolytic enzyme. The purified fibrinolytic enzyme degraded fibrin clot. The fibrinolytic enzyme could be useful to make as an effective thrombolytic agent.

Biosynthesis and characterization of keratinolytic protease from actinobacterium sp. in solid state culture.

The aim of this study was to use agro-industrial residues for the production of a halotolerant keratinolytic- protease by Actinobacterium sp. in solid-state fermentation. Among various agro-industrial residues that were evaluated, apple pomace supported maximum protease production (8400 U/g material). The optimum conditions required for enzyme production were a fermentation period of 72 h, 10% (w/v) NaCl, pH 7.0, 120% (v/w) moisture and 10% (v/w) inoculum. The enzyme exhibited activity to a range of pH (7.0-9.0) and temperature (30-45°C), with optima at 8.0 and 40 °C, respectively. Most of the divalent ions tested stimulated the protease activity and Ca2+ ion was required for its activity and stability. The enzyme was widely active at the range of NaCl concentration (5%-15%, w/v) and effectively degraded chicken feather. This protease could be useful in fish sauce fermentation and also in feed industry.