The Phytase Subfamily of Histidine Acid Phosphatases: Isolation of Genes for Two Novel Phytases from the Fungi Aspergillus Terreus and Myceliophthora Thermophila

• Published in: Microbiology (Society for General Microbiology) Vol. 143; no. 1; pp. 245 - 252
• Main Authors: Mitchell, David B, Vogel, Kurt, Weimann, Bernd J, Pasamontes, Luis, van Loon, Adolphus P. G. M
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.01.1997; Society for General Microbiology
• Subjects: 6-Phytase - classification; 6-Phytase - genetics; Acid Phosphatase - genetics; Amino Acid Sequence; Aspergillus - enzymology; Aspergillus - genetics; Aspergillus terreus; Base Sequence; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Gene Library; Genes, Fungal; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Microbiology; Mitosporic Fungi - enzymology; Mitosporic Fungi - genetics; Molecular Sequence Data; Myceliophthora thermophila; Mycology; Polymerase Chain Reaction; Sequence Homology, Amino Acid; Species Specificity; Nucleotide sequence; Enzyme; 3-Phytase; Phosphoric monoester hydrolases; Esterases; Fungi; Enzymatic activity; DNA; Hydrolases; Fungi Imperfecti; Aspergillus terreus; Aminoacid sequence; Thallophyta
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-143-1-245

Biotechnology Section, Vitamins and Fine Chemicals Division, F. Hoffmann-La Roche AG, CH-4070 Basel, Switzerland ABSTRACT Phytases catalyse the hydrolysis of phytate ( myo -inositol hexakisphosphate) to myo -inositol and inorganic phosphate. In this study genes encoding novel phytases from two different filamentous fungi, Aspergillus terreus strain 9A-1 and Myceliophthora thermophila were isolated. The encoded PhyA phytase proteins show 60% ( A. terreus ) and 48% ( M. thermophila ) identity, respectively, to the PhyA of Aspergillus niger and have 21-29% identity compared to other histidine acid phosphatases. All three PhyA proteins, in contrast to the A. niger pH 2.5-optimum acid phosphatase, prefer phytic acid as substrate and show enzyme activity at a broad range of acidic pH values. Based on their enzyme characteristics and protein sequence homology, the phytases form a novel subclass of the histidine acid phosphatase family. 1 Author for correspondence: Adolphus P. G. M. van Loon. Tel: +41 61 688 7027. Fax: +41 61 688 1645. Keywords: Aspergillus terreus, Myceliophthora thermophila, gene isolation, histidine acid phosphatase, phytase Present address: Life Systems Design, Kundmannweg 2A, CH-4147 Aesch, Switzerland.