Alternative fuels from renewable lignin-cellulosic biomass plant stalks, trunks, steams, leaves, and crop biomass waste, aim to reduce our dependence on fossil oil and to provide a source that decreases the environmental impacts of energy use.(1) Although cellulosic ethanol production has been demonstrated to work in countries like Brazil, attaining a cost-effective, commercial-scale cellulosic bio-fuel industry will require new techniques to lower the price of bio-transforming these materials into bio-fuels. Also there is a high interest in the use of “raw materials” without value in our diet so we don't want to use food crops to convert them to bio-fuels instead of that, we want to use waste crop biomass, switch grass, wood chips and other sources of lignin, cellulose and hemicelluloses. Biotechnological research is the key to accelerating the discovery of new organism that produces unknown catalytically active enzymes that can use these “raw materials” as carbon source and transform them into high energetically value products.  There is where the importance of metagenomics relies. Of the microbial diversity in different ecosystems in our planet, only 1% of those organisms are able to grow under known laboratory techniques. That means that 99% of those microorganisms with possible new genes encoding for different abilities remains undiscovered. The goal of our task is to screen a Metagenomic Library constructed from a sample of Tropical Forest soil of Puerto Rico (provided by Dr. Carlos Ríos Velázquez  Microbial Biotechnology Laboratory; Department of Biology, Mayagüez Campus) searching for enzymes that degrade cellulose, and lignocelluloses.