Purification and characterization of a protease produced by submerged fermentation: Ultrasound-enhanced...

Proteases are a large group of enzymes in high demand due to their wide and different biotechnological applications mainly in the biomedical field. Ultrasound (US) has been used successfully in several Bioprocesses in biotechnology, such as in the upregulation of enzymatic hydrolysis (biocatalysis). The objective of this work was to purify an enzyme from Streptomyces parvulus and to characterize it through physic-chemical applications including ultrasound effect. The purified protease has a molecular weight of 78.0 KDa, a yield of 31 % and 11.8-fold, it was stable between pH 4-9, optimum pH at 7.5, temperature of 0-45 °C, and showed optimum temperature at 45 °C, exhibited enhanced activity with Ca²⁺ and Mg²⁺, and was inhibited by PMSF. US in the treatment or pre-treatment of enzymatic reactions showed to be favorable and increase the activity around 85 % for the optimum temperature 45 °C. Also, in circular dichroism spectra it was shown a significant change in enzyme structure under US effect enhancing the real activity. Besides, the US improved the enzyme reactions for all assays. The purified enzyme was successfully immobilized in chitosan film. Thus, the present work demonstrated the promising results of a protease with collagenolytic activity in the field of Biotechnology by proving the positive effect induced by ultrasound.