“Extracellular proteolytic activity characterization of the alkaliphilic Bacillus sp. PAT 05 isolated from Patagonia arid soils, Argentina”

OLIVERA N., SEQUEIROS C., MARGUET E.R. Y BRECCIA J.D

Florianópolis, Brasil

Simposio; XIV Simpósio Nacional de Fermentaçoes. SINAFERM 2003; 2003

Extracellular proteolytic activity characterization of the alkaliphilic Bacillus sp. PAT 05 isolated from Patagonia arid soils, Argentina. A screening program for alkaliphilic bacteria producers of extracellular proteolytic activity using samples from Patagonia arid soils was performed. A gram-positive, sporulating bacterium was selected for activity/stability properties. The isolate PAT05 belonged to the genus Bacillus,16S rDNA (484 bp) sequence analysis showed that it is related to B. clausii and B. alcalophilus. A plato of optimal proteolytic activity of the supernatant of Bacillus sp. PAT05 was detected in the range of pH between 9-13 and the optimal temperature showed to be around 60°C. The activity was inhibited with penylmethylsulphonyl fluoride, indicating a serine-protease activity. More than 80 % of the enzyme activity was retained in the presence of 10 mM EDTA. SDS-PAGE and casein zymogram analyses confirmed the presence of two protein bands with proteolytic activity. IEF-zymogram revealed an active fraction whose isoelectric point was > 9.3.