An efficient and simple method for constructing an environmental library using mechanically sheared DNA obtained
directly from geothermal sediments is presented. The method is based on blunt-end modification of DNA
fragments followed by 3' -adenylation using Vent DNA polymerase and Taq DNA polymerase, respectively. The
prepared DNA fragments are then ligated into a TA cloning vector and used in the transformation of Escherichia
coli. This method has been successfully applied to the cloning of ORFs derived from uncultivated prokaryotes
present in geothermal sediment.