Z.M. Corales-Tirado, R.K. Rivera-Valentin, and C. Rios-Velazquez from the University of Puerto Rico-Mayagüez Biology Department screened three metagenomic libraries from Puerto Rican forests to search for protease activity. They used a function-driven analysis approach, spreading library dilutions on plates with non-fat dry milk to identify clones that could break down the milk, indicating potential protease activity. A total of 20 potential clones were identified and are being analyzed through biochemical and molecular techniques to confirm the activity and determine if it is due to the cloned fragment. Screening for proteases in detergents has great industrial importance as detergent enzymes account for

1. Abstract
Z.M. Corales-Tirado, R.K. Rivera-Valentin, C. Rios- University of Puerto Rico- Mayagüez
Velazquez
Names University
Biology Biotechnology
Department Category
Text (Times New Roman, Font 12)
Functional genomic and culture independent approaches to search for protease activity in
Forest soils in Puerto Rico
Z.M. Corales-Tirado, R.K. Rivera-Valentin, C. Rios-Velazquez, University of Puerto Rico-
Mayagüez, Biology Department.
The recognition that most microorganisms in the environment cannot be culture by standard
methods stimulated the development of metagenomics, which is the genomic analysis of uncultured
microorganisms. Modern biotechnology has a steadily increasing demand for novel bioactive
compounds, biomolecules, and enzymes. Natural and genetic diversity of the soil metagenome has
so far been the best supplier for these novel molecules. Enzymes production is one of the most
important drivers of the industrial processing industry because it uses modern biology in the
production process, and produces the biotechnological products needed for applications in other
industrial areas. Some of these industrial enzymes are the proteases, which have important
biotechnological applications and execute a large variety of functions. The proteases represent one
of the three largest groups of industrial enzymes and have application in detergents, leather
industry, food industry, pharmaceutical industry and bioremediation processes. Probably the largest
application of proteases is in laundry detergents, where they help removing proteins based strains
from clothing. Two approaches, the function-driven analysis and the sequence-driven analysis,
have emerged to extract biological information from metagenomic libraries. Here, we used the
function-driven analysis, which is initiated by identification of clones that express a desired trait,
followed by characterization of the active clones by sequence and biochemical analysis. We
screened three metagenomic libraries generated from forests in Puerto Rico. Serial dilutions of the
libraries were spread on Petri plates supplemented with non-fat dry milk. A clear zone around the
tested clones indicated clones with potential for protease activity. A total 20 potential clones were
found which have being analyzed through biochemical and molecular techniques to confirm

2. whether the activity is due to the cloned fragment. The screening of detergent proteases for
industrial production has a great importance because detergent enzymes account for about 30% of
the total worldwide enzyme production, and represent one of the largest and most successful
applications of modern industrial biotechnology.