Resumo

The marine environments that harbor extremely diverse communities of microorganisms represent very promising and little unexploited biotechnological resource for novel products. Nowadays, secreted bacterial molecules, mainly enzymes, are of special interest, since they play important role in ecological relationships influencing the growth of host organisms, as well as huge biotechnological and industrial applications. This work aimed to analyze the enzymatic activity of bacteria isolated from the scleractinian coral Siderastrea stellata. The bacterial strains were obtained from tissue of healthy and pigmentation altered (pink) colonies of S. stellata collected at Cabo Branco coral reefs, Paraiba State, Brazil. The bacteria were classified according to the cell morphology, response to Gram stain and the endospore formation. The production of extracellular cellulases and proteases was analyzed on solid mineral media with 0.1% of carboxymethylcellulose (CMC) and 2% of gelatin, respectively. The hydrolysis of CMC was detected by using 0.1% Congo red and 1M NaCl, while gelatin hydrolysis was observed using Frazier’s reactive. Among 40 isolates analyzed, three obtained from healthy S. stellata colony and four from pink colony showed cellulolytic activity, and most of the positive strains showed high production of these enzymes. Cellulolytic isolates were represented by Gram positive endospore-forming bacilli (biotype B) (71.4%) and of Gram positive bacilli without endospores (biotype A) (28.6%). Proteolytic activity was detected in eight strains isolated from healthy colony of S. stellata and four from pink colony. The isolates that produced proteases belonged to biotype A (41.7%) and B (33.3% ), and 25.0% of isolates were Gram positive cocci. Several isolates that show enzymatic activity in this study has potential to be explored in future research for biotechnological purpose.