AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Berka, R. M.
Right arrow Articles by Klotz, A. V.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Berka, R. M.
Right arrow Articles by Klotz, A. V.
Agricola
Right arrow Articles by Berka, R. M.
Right arrow Articles by Klotz, A. V.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, November 1998, p. 4423-4427, Vol. 64, No. 11
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Molecular Characterization and Expression of a Phytase Gene from the Thermophilic Fungus Thermomyces lanuginosus

Randy M. Berka, Michael W. Rey, Kimberly M. Brown, Tony Byun, and Alan V. Klotz*

Novo Nordisk Biotech, Davis, California 95616-4880

Received 17 February 1998/Accepted 10 September 1998

The phyA gene encoding an extracellular phytase from the thermophilic fungus Thermomyces lanuginosus was cloned and heterologously expressed, and the recombinant gene product was biochemically characterized. The phyA gene encodes a primary translation product (PhyA) of 475 amino acids (aa) which includes a putative signal peptide (23 aa) and propeptide (10 aa). The deduced amino acid sequence of PhyA has limited sequence identity (ca. 47%) with Aspergillus niger phytase. The phyA gene was inserted into an expression vector under transcriptional control of the Fusarium oxysporum trypsin gene promoter and used to transform a Fusarium venenatum recipient strain. The secreted recombinant phytase protein was enzymatically active between pHs 3 and 7.5, with a specific activity of 110 µmol of inorganic phosphate released per min per mg of protein at pH 6 and 37°C. The Thermomyces phytase retained activity at assay temperatures up to 75°C and demonstrated superior catalytic efficiency to any known fungal phytase at 65°C (the temperature optimum). Comparison of this new Thermomyces catalyst with the well-known Aspergillus niger phytase reveals other favorable properties for the enzyme derived from the thermophilic gene donor, including catalytic activity over an expanded pH range.

* Corresponding author. Mailing address: Novo Nordisk Biotech, Inc., 1445 Drew Ave., Davis, CA 95616-4880. Phone: (530) 757-0822. Fax: (530) 758-0317. E-mail: magi{at}nnbt.com.

Applied and Environmental Microbiology, November 1998, p. 4423-4427, Vol. 64, No. 11
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1998 by the American Society for Microbiology. All rights reserved.