Functional screening of phosphatase-encoding genes from bacterial sources

Phosphatase (APase) enzymes including phytases have broad applications in diagnostic kits, poultry feeds, biofertilizers and plant nutrition. Because of high levels of sequence diversity among phosphatases, an efficient functional screening method is a crucial requirement for the isolation of the encoding genes. This study reports a functional cloning screening method for the isolation of APase-encoding genes from bacterial genomic libraries in a medium containing a chromogenic substrate. The method was optimized to distinguish the desired signal from the background chromosomal APase activity. This screening method led to the isolation of two novel APase-encoding genes from Pseudomonas putida with no similarities to the known genes in the databases, indicating successful implementation of the developed method.