Caracterização de enzimas proteoliticas produzidas por bactérias de origem marinha

Abstract

Proteases from marine microorganisms have received increased attention due to their advantages compared to other sources. The objetive of this work was the characterization of an extracellular protease produced by a marine strain. The bacterial growth was performed in a liquid culture media, containing bacteriological peptone (1, 2 and 4%), yeast extract (0.5%) and sugar (0.5% saccharose or glucose). Bacterial growth and enzymatic activity were followed for 50 h. Best results were obtained with saccharose, yeast extract and 2% of peptone. The optimum temperature and pH were 60ºC and 6.5, respectively. However, another proteolytic activity maximum was recorded at pH 7.6. The protease was stable at 40ºC for approximately 15h, as well as when pre-incubated for 1h at temperatures between 6 and 50 ºC. However, this protease was quickly denaturated at 60ºC. The incubation of the protease at different pH showed that it was stable at pH 6.5-10.6. This protease was inhibited by EDTA and phenantroline indicating that this protease is a metalloprotease. The addition of ions like Ca2+ and Mg2+ led to an significantly increase of enzyme activity. The characteristics of this protease indicate that this enzyme may be further exploited for various industrial applications.