Safety evaluation of a phytase, expressed in Schizosaccharomyces pombe, intended for use in animal feed

BD006 phytase is the product of the Escherichia coli B appA gene expressed in Schizosaccharomyces pombe strain ASP595-1. This enzyme preparation is intended for use in animal feed applications where it improves the bioavailability of phosphate for monogastric animals. BD006 phytase was tested as an unrefined (DV006U) and a refined (DV006R) preparation for its effects on genotoxicity and in acute, inhalation and subchronic toxicity studies. Dosages ranged from 5000 mug/plate for in vitro toxicity studies to a high of 2000X for oral in vivo toxicity studies. The highest oral dose tested (2000X) is 2000 times the highest expected consumption of product by poultry or swine (X = 50 units of phytase per kg bwt/day). There was no genotoxicity or any in vivo toxicity reported which could be directly related to systemic effects of the product. Other additional safety studies conducted were devoid of any relevant toxicity. The historic safety profile of the production organism S. pombe, and the results of the toxicity studies presented herein, attest to the safety of BD006 phytase for use in animal feed applications. (C) 2003 Elsevier Science (USA). All rights reserved.