Isolation and identification of extracellular phytase-producing fungal in coastal waters of the Caspian Sea by ITS-PCR

Aim& Caspian Sea is one of the most valuable ecosystems in the world containing a high diversity of fungal species with are capable of producing the enzyme. Phytases are the most important enzymes with vast applications in industry. Phytase hydrolyzes phytic acid releasing inorganic phosphate which could resolve some of the problems caused by phytate in animal feed. The aim of this study was the isolation and identification of phytase-producing fungal from the coastal waters of the Caspian Sea. The water samples were collected from west coast of the Caspian Sea in spring 2011. The samples were cultured on Potato dextrose agar and isolates were cultured on PSM agar to identify phytase-producing fungal again. After DNA extraction, phytase producing fungal were identified via ITS-5.8S rDNA amplification and sequencing. Six phytase-producing fungal species were identified from coastal waters of the Caspian Sea. Among them, three species of Aspergillus ochraceus, Aspergillus flavus and Penicillium olsonii showed higher phytase activity. Also, the two new species Discostromatri cellulare and Cladosporium gossypiicola with accession number of JF811913 and JF811912 were verified and recorded in Genebank, respectively. However, The six species were the plant pathogens fungal which entered from environment to sea and likely to have a suitable phytase activity on phytate. Due to the pollution of the Caspian Sea caused by the phytic acids and their inhibitory effect on animal food chain it can be used for bioremediation and their enzyme for processing vegetable phosphorus.