A Tropical Composting Operation Unit at São Paulo Zoo as a Soure of Bacterial Proteolytic Enzymes

Composting operation systems are valuable sources of microorganisms and enzymes. This work reports the assessment of proteolytic enzymes from cultivable bacteria isolated from a composting facility of the Sao Paulo Zoo Park (SPZPF), Sao Paulo, Brazil. Three hundred bacterial isolates were obtained and identified based on 16S rRNA gene as belonging to 13 different genera. The most common genus among the isolates was Bacillus (67%); some of which show high proteolytic activity in their culture media. Biochemical assays of hydrolytic activities using FRET peptides as substrates allowed the characterization of a repertoire of serine proteases and metalloproteases with different molecular weights secreted by Bacillus strains isolated from composting. Furthermore, thermostable serine and metalloproteases were detected in the composting leachate, which might be of interest for industrial applications.